TY - JOUR AU - Abele, E. AU - Abele, R. AU - Lukevics, E. PY - 2007 TI - Oximes of Five-membered Heterocyclic Compounds with two Heteroatoms. Part 1. Synthesis and Structure SP - 387-407 KW - Oxazole oximes Thiazole oximes Imidazole oximes AB - Review. Data on the prodn. and structure of oxazole, thiazole, and imidazole aldoximes, ketoximes, and amidoximes and their derivs. are reviewed. JO - Chemistry of Heterocyclic Compounds VL - 43(4) ER - TY - JOUR AU - Akiyama, T. PY - 2007 TI - Stronger Bronsted Acids SP - 5744-58 KW - Bronsted acids, catalysts AB - A review. The application of Bronsted acids as catalysts in various reactions is discussed in detail. JO - Chemical Reviews VL - 107(12) ER - TY - JOUR AU - Albu, T.V. AU - Espinosa-Garcia, J. AU - Truhlar, D.G. PY - 2007 TI - Computational Chemistry of Polyatomic Reaction Kinetics and Dynamics: The Quest for an Accurate CH5 Potential Energy Surface SP - 5101-32 KW - Potential energy surface, CH5 AB - A review. Over more than six decades, the H + CH4 reaction and its isotopic variants have represented a target against which to test kinetics and dynamics theories and potential energy surfaces for polyat. reactions. This comprehensive review concerns the development of a multidimensional potential energy surface for the CH5 system and how dynamics calcns. on the various approx. surfaces, that have been developed, compare with exptl. detd. kinetic and dynamic parameters. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Alcaide, B. AU - Almendros, P. AU - Aragoncillo, C. PY - 2007 TI - .b.-Lactams: Versatile Building Blocks for the Stereoselective Synthesis of Non-.b.-Lactam Products SP - 4437-92 KW - Lactams, .b.-, in synthesis Azetidinones, non-.b.-lactam products AB - A review. This review is to surveys the vast chem. of 2-azetidinones for the prepn. of non-.b.-lactam products (non-proteinogenic .a.-amino acids, different kinds of heterocycles, alkaloids, macrolides, taxoids, etc.), concg. on the advances that have been made in the past decade, in particular in the last 5 years. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Aleu, J. AU - Bustillo, A.J. AU - Hernandez-Galan, R. AU - Collado, I.G. PY - 2007 TI - Biocatalysis Applied to the Synthesis of Pheromones SP - 693-705 KW - Pheromones, via biocatalysis AB - A review. The application of biol. derived catalysts to the synthesis of agrochems. has become increasingly popular in recent years. In most cases, the aim of using a biotransformation is either to introduce chirality into the mol., to achieve a regioselective functionalization, or to selectively convert a functional group among other groups with similar reactivity. Pheromones, which have recently been commercialized as agrochems., are generally used in enantiopure forms with their intentional mixts. Since they are usually highly effective, only very small quantities are needed to achieve the desired activity. This review, with approx. 200 refs. covering the period previous to Dec. 2004, describes various efficient means of prepg. optically pure pheromones and their precursors with the aid of isolated enzymes and microorganisms serving as catalysts. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Angell, Y.L. AU - Burgess, K. PY - 2007 TI - Peptidomimetics via Copper-Catalyzed Azide-Alkyne Cycloadditions SP - 1674-89 KW - Peptidomimetics, azide-alkyne cycloaddition Azide-alkyne cycloaddition Click reaction AB - A review. This crit. review concerns the impact of copper-mediated alkyne-azide cycloaddns. on peptidomimetic studies. It discusses how this reaction has been used to insert triazoles into peptide chains, to link peptides to other functionalities (e.g. carbohydrates, polymers, and labels), and as a basis for evolution of peptidomimetics as pharmaceutical leads. This work will be of interest to those studying "Click reaction", peptidomimetic secondary structure and function, and to medicinal chemists. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Antinolo, A. AU - Garcia-Yuste, S. AU - Otero, A. AU - Villasenor, E. PY - 2007 TI - On the Insertion Processes of Unsaturated Molecules into the Nb-X .s.-bond of "Cp'2NbX" Moieties (Cp' = .h.5-C5H4SiMe3; X = H, C, P) SP - 4436-47 KW - Niobocene, insertion reactions AB - A review on a series of insertion processes of different types of unsatd. reagents, namely carbon monoxide, carbon dioxide, isocyanates, isothiocyanates, isonitriles, alkenes and activated alkynes, in the Nb-X .s.-bond, of hydrides (X = H), .s.-organometallic compds. (X = C) and phosphine complexes (X = PR3) of niobocene moieties Cp'2NbX (Cp' = .h.5-C5H4SiMe3). JO - Journal of Organometallic Chemistry VL - 692 ER - TY - JOUR AU - Antonova, A.B. PY - 2007 TI - Use of the Mn:C:C System in Organometallic and Organic Synthesis SP - 1521-60 KW - Organometallics, Mn:C:C system AB - A review. The present review summarizes the syntheses, structures, physicochem. properties and reactivity of complexes contg. .h.1-, .m.-, .m.3- and .m.4-vinylidene ligands. Consideration of mononuclear vinylidene complexes is limited to cymantrene derivs., one of which, viz. Cp(CO)2Mn:C:CHPh (1), has served as the precursor for syntheses of many organometallic and some org. compds. The reactions between phosphites P(OR)3 and complex 1 afford styrylphosphonates PhCH:CHP(O)(OR)2. All the transformations of complex 1 occur under very mild conditions. Special attention is paid to heterometallic complexes, contg. Mn, Fe and the Pt Group metals with bridging vinylidene ligands. The Mn:C:CHR system was used as a building block for dimetal .m.-vinylidene complexes including Mn-M bonds (M = Mo, W, Mn, Re, Fe, Rh, Pd, Pt, Cu) and trimetallic MnFePt .m.3-vinylidene clusters. Transmetalation reactions of the MnPd and MnPt complexes gave .m.4-vinylidene PdFe3 and PtFe3 clusters. Transfer of vinylidene from the Mn atom to another metal atom (Re), to the dinuclear (FePt) and cluster (Os3, PdFe3, PtFe3) systems was shown. A systematic study of a dependence of structural and spectroscopic parameters of mono-, di-, tri- and tetra-nuclear complexes on the vinylidene coordination mode was carried out. JO - Coordination Chemistry Reviews VL - 251 ER - TY - JOUR AU - Arisawa, M. AU - Terada, Y. AU - Takahashi, K. AU - Nakagawa, M. AU - Nishida, A. PY - 2007 TI - Non-Metathesis Reactions of Ruthenium Carbene Catalysts and Their Application to the Synthesis of Nitrogen-containing Heterocycles SP - 238-53 KW - Heterocycles, N-containing, Ru Ruthenium carbens, non-metathesis reactions AB - A review. Non-metathesis reactions of ruthenium carbene catalysts, such as olefin isomerization, hydrogenation, radical reaction, activation of silane, cyclopropanation, epimerization of cyclopropane, [3 + 2] cycloaddn., and cycloisomerization, are summarized. The utility of these reactions was demonstrated by the synthesis of indole using olefin isomerization and subsequent ring-closing metathesis, the synthesis of indoline using cycloisomerization, and the synthesis of the putative structure of fistulosin using cycloisomerization as a key step. JO - Chemical Record VL - 7 ER - TY - JOUR AU - Atzrodt, J. AU - Derdau, V. AU - Fey, T. AU - Zimmermann, J. PY - 2007 TI - The Renaissance of H/D Exchange SP - 7744-65 KW - Deuterium labelling AB - A review. The increasing demand for stable isotopically labeled compds. has led to an increased interest in H/D-exchange reactions at carbon centers. Today deuterium-labeled compds. are used as internal stds. in mass spectrometry or to help elucidate mechanistic theories. Access to these deuterated compds. takes place significantly more efficiently and more cost effectively by exchange of hydrogen by deuterium in the target mol. than by classical synthesis. This review will conc. on the preparative application of the H/D-exchange reaction in the prepn. of deuterium-labeled compds. Advances over the last ten years are brought together and critically evaluated. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Aversa, M.C. AU - Barattucci, A. AU - Bonaccorsi, P. AU - Giannetto, P. PY - 2007 TI - Recent Advances and Perspectives in the Chemistry of Sulfenic Acids SP - 1034-52 KW - Sulfenic acids AB - A review. This review provides a comprehensive survey of the literature on sulfenic acid chem. from 1990 through June 2006, focusing the attention on salient aspects of their structures and involvement in org. processes. Even if the majority of known sulfenic acids cannot be isolated, some stable ones were obtained, and their study helped dramatically the comprehension of chem. and phys. properties of all sulfenic acids and indirectly of the role that Cys-SOHs play in protein biochem. Many papers were published in the last fifteen years about the sulfenic acid intermediacy in org. chem. Once generated, they can be involved in intra- and intermol. addns. to unsatd. mols. Few examples of sulfenic acid addn. to double bonds were recently described and most of them are intramol. processes, whereas the addn. of enantiopure sulfenic acids onto carbon-carbon triple bonds was widely exploited in the synthesis of vinyl sulfoxides to be used in many stereoselective transformations. The thermic .b.-elimination from sulfinyl precursors is a way to generate sulfenic acids but it was also used for removing the sulfinyl moiety from org. mols. and forming double bonds with controlled stereochem. Some significant applications of extrusion processes are also described in the present review. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Bagley, M.C. AU - Glover, C. AU - Merritt, E.A. PY - 2007 TI - The Bohlmann-Rahtz Pyridine Synthesis: From Discovery to Applications SP - 2459-82 KW - Pyridine synthesis AB - A review of our research into the Bohlmann-Rahtz pyridine synthesis. The historic discovery of this reaction and its mechanism are discussed, followed by recent improvements in methodol., such as Bronsted and Lewis acid catalysis, microwave assistance, use of a continuous flow reactor, and incorporation into multicomponent and tandem reactions. Applications of these methods in the synthesis of pyrido[2,3-d]pyrimidines, combinatorial pyridine libraries, heterocyclic .a.- and ?-amino acids, .a.-helix mimetics, and complex natural products are discussed, along with a consideration of future perspectives. JO - Synlett ER - TY - JOUR AU - Ballini, R. AU - Palmieri, A. AU - Righi, P. PY - 2007 TI - Highly Efficient One- or Two-step Sequences for the Synthesis of Fine Chemicals from Versatile Nitroalkanes SP - 12099-121 KW - Nitroalkanes, transformations AB - A review. Environmental and economic pressures are now forcing the chem. community to search for more efficient ways of performing chem. transformations. Nitroalkanes are a valuable source of stabilized carbanions since the high electron-withdrawing power of the nitro group provides an outstanding enhancement of the hydrogen acidity at the .a.-position. The nitronate anions that can be generated from nitroalkanes under basic conditions act as carbon nucleophiles with common electrophiles, leading to single or double carbon-carbon bond formation. Moreover, the nitro group can be easily turned into a respectable array of JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Balskus, E.P. AU - Jacobsen, E.N. PY - 2007 TI - Asymmetric Catalysis of the Transannular Diels-Alder Reaction SP - 1736-40 KW - Diels-Alder reaction, transannular, asymmetric Terpenes, via transannular Diels-Alder Polycycles, via transannular Diels-Alder AB - Transannular chem. reactions are unparalleled in their ability to generate high degrees of stereochem. and architectural complexity in a single transformation. However, the successful application of this approach in synthesis depends on the ability to predict and control the outcome of the transannular reaction. Use of a chiral catalyst in this context represents an attractive, yet unused, strategy. This report describes a catalytic, asym. transannular Diels-Alder (TADA) reaction that affords polycyclic products in high enantiomeric excess. This catalyst system can also alter the inherent diastereoselectivity of cyclizations with substrates contg. chiral centers. Addnl., the catalytic enantioselective TADA has been used as the key step in a total synthesis of the sesquiterpene 11,12-diacetoxydrimane (I); this route may provide a general approach to the polycyclic carbon framework shared by many terpene natural products. JO - Science VL - 317(5845) ER - TY - BOOK AU - Barnes, A.J. AU - Koll, A. AU - Ratajczak, H. AU - Eds PY - 2007 BT - Special Issue: Studies of Hydrogen-Bonded Systems: [In: J. Mol. Structure, 2007; 844-845] CY - Amsterdam, Netherlands PB - Elsevier KW - Hydrogen-bonded systems, book ER - TY - JOUR AU - Basavaiah, D. AU - Rao, K.V. AU - Reddy, R.J. PY - 2007 TI - The Baylis-Hillman Reaction: A Novel Source of Attraction, Opportunities, and Challenges in Synthetic Chemistry SP - 1581-8 KW - Baylis-Hillman reaction AB - A review. The Baylis-Hillman reaction is a successful, useful, and atom-economical carbon-carbon bond forming reaction, which has grown from an obscure level to the level of high synthetic popularity due to its operational simplicity and also due to the enormous applications of the Baylis-Hillman adducts in org. synthesis. In this tutorial review, we briefly describe the way this reaction has grown to its present heights and the opportunities, attractions, and challenges the reaction offers with respect to its asym. and intramol. versions, and mechanistic aspects. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Bellur, E. AU - Feist, H. AU - Langer, P. PY - 2007 TI - Recent Advances in the Chemistry of 2-(2-Oxoalkylidene)tetrahydrofurans SP - 10865-88 KW - Alkylidenetetrahydrofurans AB - A review dealing with the synthesis of 2-alkylidenetetrahydrofurans and the reactions of 2-alkylidenetetrahydrofurans such as alkylations, brominations, Suzuki coupling reactions, hydrogenation, etc. JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Bertelsen, S. AU - Nielsen, M. AU - Joergensen, K.A. PY - 2007 TI - Radicals in Asymmetric Organocatalysis SP - 7356-9 KW - Radicals, aminocatalysis Aminocatalysis, with radicals AB - A review on how aminocatalysis has developed into a versatile tool for the stereoselective functionalization of carbonyl species. In the search for new organocatalytic transformations. attention has been focused on radicals to expand the scope of aminocatalysis. The successful application of the SOMO (singly occupied MO)-enamine activation has led to a no. of novel transformations. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Bowman, W.R. AU - Storey, J.M.D. PY - 2007 TI - Synthesis using Aromatic Homolytic Substitution-Recent Advances SP - 1803-22 KW - Aromatics, homolytic substitution AB - A review. This crit. review aims at presenting recent developments in intramol. arom. homolytic substitution which has become one of the common methodologies in modern synthesis. The application of Bu3SnH-mediated cyclisations have proved esp. useful. The crit. review illustrates the mechanistic considerations required for planning synthetic applications and a wide range of synthetic protocols and natural product syntheses are shown. The latest evidence for the mechanisms involved in arom. homolytic substitution are presented. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Brackmann, F. AU - De Meijere, A. PY - 2007 TI - Natural Occurrence, Syntheses, and Applications of Cyclopropyl-Group- Containing .a.-Amino Acids. 2. 3,4- and 4,5-Methanoamino Acids SP - 4538-83 KW - Cyclopropylglycines Cyclopropylalanines Methanoamino acids AB - A review. Since research towards 3,4- and 4,5-methanoamino acids, also called cyclopropylglycines and cyclopropylalanines, resp., is a relatively new area that had attracted little attention until 20 years ago, its achievements have not been summarized so far. Thus, this review is intended to particularly compile and briefly discuss the biol. properties, pharmacol. activities, and successful synthesis of 3,4- and 4,5-methanoamino acids. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Brackmann, F. AU - De Meijere, A. PY - 2007 TI - Natural Occurrence, Syntheses, and Applications of Cyclopropyl-Group- Containing .a.-Amino Acids. 1. 1-Aminocyclopropanecarboxylic Acid and Other 2,3-Methanoamino Acids SP - 4493-537 KW - Aminocyclopropanecarboxylic acids Methanoamino acids AB - A review. This review is intended to compile the various syntheses, biol. properties, and pharmacol. activities of 1-aminocyclopropanecarboxylic acid, the unsubstituted 2,3-methanoamino acid, and its substituted derivs. thereof. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Braune, S. AU - Deb, S. AU - Hase, T. AU - Wahala, K. PY - 2007 TI - Homologation of Estrone or Estradiol. Appending a Carbon Substituent into the 3-Hydroxyestra-1,3,5-Triene Skeleton SP - 383-405 KW - Estrone, homologation Estradiol, homologation AB - A review. Recent work is reviewed concerning the synthesis of estrone or estradiol homologues, of interest in diagnostics, drug discovery research etc. The survey is limited to reactions where a carbon atom or a carbon chain becomes directly attached to the steroid ring system. Also conversions of non-estranoid starting materials to substituted estrone/estradiol derivs. are discussed. The organization of the review follows steroid numbering. JO - Current Organic Chemistry VL - 11 ER - TY - BOOK AU - Brown, D.J. AU - Wipf, P. AU - Taylor, E.C. AU - Eds PY - 2005 BT - Cinnolines and Phthalazines: Chemistry of Heterocyclic Compounds, Supplement II; Vol. 64 CY - Hoboken, N.J. PB - Wiley SP - 500 KW - Heterocycles, cinnolines, book Heterocycles, phthalazines, book ER - TY - JOUR AU - Bullock, R.M. PY - 2007 TI - An Iron Catalyst for Ketone Hydrogenations under Mild Conditions SP - 7360-3 KW - Ketones, hydrogenation, with Fe AB - A review on the use of an iron-based homogeneous catalyst for ketone hydrogenation was reported, thus avoiding the used of a precious metal. Excellent yields and chemoselectivity for hydrogenation are found under mild conditions (25°C, 3 atm H2). An ionic hydrogenation mechanism allows the delivery of a proton from the OH group and a hydride from the metal center. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Cano, J. AU - Sudupe, M. AU - Royo, P. PY - 2007 TI - Synthesis and Reactivity of Di(silylamido)cyclopentadienyl Titanium and Zirconium Complexes SP - 4448-59 KW - Di(silylamido)cyclopentadienyl ligand Ethene polymerization catalysts AB - A review. The authors present in this account the synthesis and recent developments of a new class of Group 4 metal complexes with the tridentate di(silylamido)cyclopentadienyl ligand. These doubly silyl-bridged Group 4 metal amido chelates are receiving increasing interest as they are efficient catalysts for ethene polymn. when activated with MAO despite generating 14-electron d0 cationic species free of the alkyl group required for the 1st insertion reaction in the polymn. process. JO - Journal of Organometallic Chemistry VL - 692 ER - TY - JOUR AU - Catellani, M. AU - Motti, E. AU - Della Ca, N. AU - Ferraccioli, R. PY - 2007 TI - Recent Developments in Catalytic Aryl Coupling Reactions SP - 4153-65 KW - Aryl coupling, with metallacycles AB - A review. The present microreview is aimed at describing the evolution of the methodol. used in aryl coupling reactions towards catalytically efficient and highly selective procedures, which have been achieved through the use of assisted and metallacycle-directed reactions. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Chapelon, A.-S. AU - Moraleda, D. AU - Rodriguez, R. AU - Ollivier, C. AU - Santelli, M. PY - 2007 TI - Enantioselective Synthesis of Steroids SP - 11511-616 KW - Steroids, enantioselective synthesis AB - A review. JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Chen, M.S. AU - White, M.C. PY - 2007 TI - A Predictably Selective Aliphatic C-H Oxidation Reaction for Complex Molecule Synthesis SP - 783-7 KW - C-H oxidation, Fe with H2O2 AB - Realizing the extraordinary potential of unactivated sp3 C-H bond oxidn. in org. synthesis requires the discovery of catalysts that are both highly reactive and predictably selective. We report an iron (Fe)-based small mol. catalyst that uses hydrogen peroxide (H2O2) to oxidize a broad range of substrates. Predictable selectivity is achieved solely on the basis of the electronic and steric properties of the C-H bonds, without the need for directing groups. Addnl., carboxylate directing groups may be used to furnish five-membered ring lactone products. We demonstrate that these three modes of selectivity enable the predictable oxidn. of complex natural products and their derivs. at specific C-H bonds with preparatively useful yields. This type of general and predictable reactivity stands to enable aliph. C-H oxidn. as a method for streamlining complex mol. synthesis. JO - Science VL - 318(5851) ER - TY - JOUR AU - Chizhevsky, I.T. PY - 2007 TI - Large-cage (11-13-vertex) Dicarbon Metallacarboranes of Platinum Metals with Mono- and Polycyclic Diolefin Ligands SP - 1590-619 KW - Metallacarboranes, Pt, diolefin ligands AB - A review. Different types of 11-13-vertex metallacarboranes of Pt metals with unsatd. .p.-hydrocarbon ligands derived from mono- and polycyclic diolefins are reviewed. The purpose is to provide an overview of significant findings and trends in the synthetic and structural chem. of these compds. Some basic information on their catalytic and unique chem. properties, including the results on fluxional behavior and transformations of agostic (C-H···M) metallacarboranes in soln., are also discussed. JO - Coordination Chemistry Reviews VL - 251 ER - TY - JOUR AU - Clavier, H. AU - Grela, K. AU - Kirschning, A. AU - Mauduit, M. AU - Nolan, S.P. PY - 2007 TI - Sustainable Concepts in Olefin Metathesis SP - 6786-801 KW - Olefin metathesis, Ru AB - A review. Ruthenium-catalyzed olefin metathesis reactions represent an attractive and powerful transformation for the formation of new carbon-carbon double bonds. This area is now quite familiar to most chemists as numerous catalysts are available that enable a plethora of olefin metathesis reactions. Nevertheless, with the exception of uses in polymn. reactions, only a limited no. of industrial processes use olefin metathesis. This is mainly due to difficulties assocd. with removing ruthenium from the final products. In this context, a no. of studies have been carried out to develop procedures for the removal of the catalyst or the products of catalyst decompn., however, none are universally attractive so far. This situation has resulted in tremendous activity in the area dealing with supported or tagged versions of homogeneous catalysts. This Review summarizes the numerous studies focused on developing cleaner ruthenium-catalyzed metathesis processes. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Coleman, A.W. AU - Perret, F. AU - Moussa, A. AU - Dupin, M. AU - Guo, Y. AU - Perron, H. PY - 2007 TI - Calix[n]arenes as Protein Sensors SP - 31-88 KW - Calixarenes, protein sensors AB - A review. The use of calix[n]arene derivs. for the sensing of proteins is described. Initially the properties of the calix[n]arenes are described. In order to better understand how the calix[n]arenes may be used for protein sensors, a detailed survey of the interactions between the mols. and amino acids and peptides is presented. The known complexes between proteins and various calix[n]arene derivs. is described and the biol. activity of the mols. summarized. The use of calix[n]arenes as protein sensors obsd. by Scharader using amphiphilic calix[n]arenes shows that these mols. may allow nanomolar sensing. The major section of the work deals with the development of a para-sulfonato-calix[n]arene-based system for the prion protein responsible for bovine spongiform encephalitis and variant-Creutzfeldt-Jacobs disease(v-CJD) in humans. Initially, the development of the test was based on a Western Blot detection, however, the need for large scale testing after the discovery that blood transfusion may lead to infection with v-CJD led to the transfer of the technol. to an ELISA-based test. JO - Topics in Current Chemistry VL - 277 ER - TY - JOUR AU - Compain, P. PY - 2007 TI - Olefin Metathesis of Amine-Containing Systems. Beyond the Current Consensus SP - 1829-46 KW - Olefin metathesis, to amine heterocycles Olefin metathesis, to alkaloids AB - A review. Olefin metathesis is one of the most powerful synthetic tool to access amine-contg. heterocycles and alkaloids. A major drawback assocd. with the use of amines concerns their ability to coordinate to metal-alkylidene complexes and to interfere unproductively with catalytic activity. Based on literature precedents, it was established as a dogma that efficient metathesis reactions are suppressed in the presence of basic amines and that such substrates must invariably be deactivated by conversion of the amines to the corresponding carbamates or ammonium salts. However, an increasing no. of examples of amine-contg. compds. that are good substrates for metathesis is being reported in the literature. How can this non-classical reactivity be rationalized and exploited. The purpose of this review was to provide an overview of successful metathesis reactions performed with amine-contg. compds. in order to allow some guidelines to be formulated. A special emphasis was placed on the different parameters that may influence the outcome of the reaction such as steric effects, amine basicity, and the nature of the catalyst. JO - Advanced Synthesis & Catalysis VL - 349 ER - TY - JOUR AU - Davies, A.G. PY - 2007 TI - Organosilicon Peroxides: Radicals and Rearrangements SP - 10385-405 KW - Organosilicon peroxides AB - A review. JO - Tetrahedron VL - 63 ER - TY - BOOK AU - de Vries, J.G. AU - Elsevier, C.J. AU - Eds PY - 2007 BT - Handbook of Homogeneous Hydrogenation, Vol. 2-3 CY - Weinheim, Germany PB - Wiley-VCH SP - 535 KW - Hydrogenation, homogeneous, book ER - TY - JOUR AU - Diaz, D.J. AU - Darko, A.K. AU - McElwee-White, L. PY - 2007 TI - Transition Metal-Catalyzed Oxidative Carbonylation of Amines to Ureas SP - 4453-65 KW - Amines, carbonylation to ureas Ureas, from amines, via CO AB - A review. The synthesis of ureas from amines has traditionally been accomplished with stoichiometric reactions of phosgene or its derivs., which are assocd. with environmental and waste disposal issues. Because of the prevalence of urea moieties in mols. of interest for several applications, alternative catalytic routes for the oxidative conversion of amines to ureas using CO as the carbonyl source have been developed. This microreview discusses recent developments in transition metal-catalyzed oxidative carbonylation of amines to ureas as an alternative to phosgene and its derivs. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Dieguez, M. AU - Claver, C. AU - Pamies, O. PY - 2007 TI - Recent Progress in Asymmetric Catalysis using Chiral Carbohydrate-Based Ligands SP - 4621-34 KW - Carbohydrate ligands, asymmetric catalysis Phosphine ligands, asymmetric catalysis AB - A review describes the use of the most representative carbohydrate deriv. ligands in asym. catalysis between 1972 and 2006 (approx.). Particular emphasis is placed on the latest results published in the most active period of this area of research (1998 to Jan. 2007). In the 1st sections the results obtained using homodonor ligands were covered, such as phosphines, phosphinites, phosphites and dithioethers. In the next sections, the authors present the results of using heterodonor ligands, such as P-P', P-S, P-N and N-S ligands. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Diez-Gonzalez, S. AU - Nolan, S.P. PY - 2007 TI - N-Heterocyclic Carbene-Copper(I) Complexes in Homogeneous Catalysis SP - 2158-67 KW - Carbenes, N-heterocyclic, copper complexes AB - A review. N-Heterocyclic carbenes (NHCs) have become increasingly popular as ligands for transition metals, thanks to their remarkable successes in metathesis and cross-coupling areas. Important advances have also been achieved in organocopper chem. To date, the reported neutral N-heterocyclic carbene-copper(I) complexes have shown outstanding catalytic activity. In this account, authors describe the application of such complexes in a variety of org. transformations. JO - Synlett ER - TY - JOUR AU - Dunne, J.F. AU - Woo, L.K. PY - 2006 TI - Synthesis and Reactivity of Molybdenum Imido Diamido Metallacyclopentenes and Metallacyclopentadienes and the Mechanism of Ethylene Exchange with Metallacyclopentane Complexes SP - 186-92 KW - Metallacyclopentenes AB - A review. The title research of E. Ison, K. Abboud and J. Boncella (2006) is reviewed with commentary and 5 refs. JO - Chemtracts VL - 19 ER - TY - BOOK AU - Dyker, G. AU - Ed PY - 2005 BT - Handbook of C-H Transformations: Applications in Organic Synthesis, Vol. 2 CY - Weinheim, Germany PB - Wiley-VCH KW - C-H transformations, book ER - TY - JOUR AU - Eisch, J.J. AU - Fregene, P.O. AU - Gitua, J.N. PY - 2007 TI - The Epimetallation and Carbonation of Carbonyl and Imino Derivatives: Epivanadation Route to 2-Amino and 2-Hydroxy Acids SP - 4647-53 KW - Ketones, hydrocarboxylation Aldehydes, hydrocarboxylation Imines, hydrocarboxylation AB - The feasibility of hydrocarboxylating carbonyl and imino derivs. by the two-step process of epimetallation and carbonation has been demonstrated with the model substrates of 9-fluorenone and 9-fluorenone anil. With lithium vanadium dihydride as the epimetallating agent, such hydrocarboxylation has led to 75% yield of 9-hydroxy-9-fluorenecarboxylic acid and a 65% yield of 9-(N-phenylamino)-9-fluorenecarboxylic acid, resp. Some initial success in extending the scope of this reaction to other substrates, such as benzophenone, has been achieved by using other epimetallating agents, like the presumed LiV(CH3)2 and Ti(OCHMe2)2. A brief review of the processes and org. synthetic applications of epimetallation and transfer epimetallation of C-C .p.-bonds is offered as background. JO - Journal of Organometallic Chemistry VL - 692 ER - TY - JOUR AU - Enders, D. AU - Niemeier, O. AU - Henseler, A. PY - 2007 TI - Organocatalysis by N-Heterocyclic Carbenes SP - 5606-55 KW - Carbenes, N-heterocyclic, organocatalysis Thiazol-2-ylidenes Triazol-2-ylidenes Imidazol-2-ylidenes Diketones, 1,4-, N-heterocyclic carbenes AB - A review. This review highlights the extensive applications and reaction pathways of thiazol-, triazol-, imidazol-, and imidazolin-2-ylidenes as versatile synthetic methods. JO - Chemical Reviews VL - 107(12) ER - TY - BOOK AU - Enders, D. AU - Jaeger, K.-E. AU - Eds PY - 2007 BT - Asymmetric Synthesis with Chemical and Biological Methods CY - Weinheim, Germany PB - Wiley-VCH SP - 445 KW - Asymmetric synthesis, book ER - TY - JOUR AU - Federsel, H.-J. AU - Hedberg, M. AU - Qvarnstroem, F.R. AU - Sjoegren, M.P.T. AU - Tian, W. PY - 2007 TI - Construction of a Chiral Central Nervous System (CNS)-Active Aminotetralin Drug Compound Based on a Synthesis Strategy Using Multitasking Properties of (S)-1-Phenylethylamine SP - 1377-84 KW - Phenylethylamine, AR-A2 synthesis Aminotetralin AR-A2 drug synthesis AB - A review. This Account describes the design and development of a scalable synthesis for the drug mol. AR-A2 ((2R)-4-(morpholin-4-yl)-N-[1,2,3,4- tetrahydro-5-methyl-8-(4-methylpiperazin-1-yl)naphthalen-2-yl]benzamide) starting from the discovery route originating in medicinal chem. Special emphasis is placed on the introduction of the correct (R) stereochem. on C2, which was ultimately achieved in a diastereoselective imine-reducing step applying NaBH4. After optimization, this transformation was operated on a large pilot-plant scale (2000 L), offering the desired product (((2R)-8-bromo-1,2,3,4-tetrahydro-5-methylnaphthalen-2-yl)((1S)-1- phenylethyl)amine) in 55% yield and 96% diastereomeric excess at a 100 kg batch size. From a synthesis strategy point of view, the choice of (S)-1-phenylethylamine was crucial not only for its role as a provider of the NH2 functionality and the stereo-directing abilities but also as an excellent protecting group in the subsequent N-arylation reaction, according to the Buchwald-Hartwig protocol. As one of the very 1st examples in its kind, the latter step was scaled up to pilot manufg. (125 kg in 2500 L vessel size), delivering an outstanding isolated yield of 95%. This consecutive series of chem. transformations was completed with an environmentally friendly removal of the phenethyl appendage. An elegant method to synthesize the tetralone substrate 8-bromo-3,4-dihydro-5- methylnaphthalen-2(1H)-one, as well as a novel and robust procedure to use imidazole as a buffer for the selective formation of the mono-HBr salt of AR-A2, will be briefly described. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Ferber, B. AU - Kagan, H.B. PY - 2007 TI - Metallocene Sulfoxides as Precursors of Metallocenes with Planar Chirality SP - 493-507 KW - Metallocene sulfoxides AB - A review. The prepn. of metallocene sulfoxides and their ortho-diastereoselective functionalization are described. The applications of enantiopure 1,2- and 1,3-disubstituted metallocenes are reviewed, with special emphasis on the prepn. of ligands for asym. catalysis. The sulfoxide functionality is a useful, traceless, chiral diastereoselective ortho-directing group, as explained in the article. It allows one to synthesize a wide range of enantiopure metallocenes with planar chirality and predictable configuration. Most of the examples are related to the ferrocene area. JO - Advanced Synthesis & Catalysis VL - 349 ER - TY - JOUR AU - Ferrand, Y. AU - Crump, M.P. AU - Davis, A.P. PY - 2007 TI - A Synthetic Lectin Analog for Biomimetic Disaccharide Recognition SP - 619-22 KW - Lectin analog Disaccharide receptor, synthetic AB - Carbohydrate recognition is biol. important but intrinsically challenging, for both nature and host-guest chemists. Saccharides are complex, subtly variable, and camouflaged by hydroxyl groups that hinder discrimination between substrate and water. We have developed a rational strategy for the biomimetic recognition of carbohydrates with all-equatorial stereochem. (.b.-glucose, analogs, and homologs) and have now applied it to disaccharides such as cellobiose. Our synthetic receptor showed good affinities, not unlike those of some lectins (carbohydrate-binding proteins). Binding was demonstrated by NMR, induced CD, fluorescence spectroscopy, and calorimetry, all methods giving self-consistent results. Selectivity for the target substrates was exceptional; minor changes to disaccharide structure (for instance, cellobiose to lactose) caused almost complete suppression of complex formation. JO - Science VL - 318(5850) ER - TY - JOUR AU - Ferraris, D. PY - 2007 TI - Catalytic, Asymmetric Alkylation of Imines SP - 9581-97 KW - Imines, asymmetric alkylation AB - A review. Two main strategies exist for the catalytic, asym. alkylation of imines. The first strategy is a chiral Lewis acid approach. This approach employs the use of a transition metal catalyst bound to a chiral ligand. The second strategy employed in catalytic, asym. alkylation of imines is the chiral nucleophile approach. In this approach, the chiral agent is either directly or indirectly part of the nucleophile before addn. to the imine. JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Flynn, A.B. AU - Ogilvie, W.W. PY - 2007 TI - Stereocontrolled Synthesis of Tetrasubstituted Olefins SP - 4698-745 KW - Alkenes, tetrasubstituted AB - A review discusses the regio- and stereoselective synthesis of various tetrasubstituted olefins. The reactions reviewed include carbometalation of alkynes using copper-, boron-, tin-, or magnesium-based organometallic reagents, carbonyl olefination, olefin metathesis, elimination and cyclization reactions, and olefin modifications. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Gansaeuer, A. AU - Fan, C.-A. AU - Keller, F. AU - Karbaum, P. PY - 2007 TI - Regiodivergent Epoxide Opening: A Concept in Stereoselective Catalysis Beyond Classical Kinetic Resolutions and Desymmetrizations SP - 8084-90 KW - Epoxide opening, regiodivergent AB - A review. An approach to highly regiodivergent epoxide openings (REOs) is presented. The very popular kinetic resolns. of epoxides and openings of meso-epoxides constitute subclasses of such REOs. REOs are attractive for parallel resolns., double asym. reactions of enantiomerically enriched epoxides, and for semisynthetic applications in the functionalization of JO - Chemistry--A European Journal VL - 13 ER - TY - JOUR AU - Garabatos-Perera, J.R. AU - Saez-Diaz, R.I. PY - 2006 TI - New Highly Efficient Ruthenium Metathesis Catalysts SP - 270-9 KW - Ruthenium metathesis catalysts AB - A review. The title research of J. S. Kingsbury, J. P. A. Harrity, P. J. Bonitatebus and A. H. Hoveyda, et. al. (1999-2006) is reviewed with commentary and 13 refs. JO - Chemtracts VL - 19 ER - TY - JOUR AU - Gibson, S.E. AU - Rudd, M. PY - 2007 TI - The Role of Secondary Interactions in the Asymmetric Palladium-Catalyzed Hydrosilylation of Olefins with Monophosphine Ligands SP - 781-95 KW - Alkenes, hydrosilylation AB - A review presents a structure-activity survey of monophosphine ligands used in the asym. Pd-catalyzed hydrosilylation reaction of olefins and used to assess the role of secondary interactions on catalyst activity and selectivity. JO - Advanced Synthesis & Catalysis VL - 349 ER - TY - JOUR AU - Glueck, D.S. PY - 2007 TI - Metal-Catalyzed Asymmetric Synthesis of P-Stereogenic Phosphines SP - 2627-34 KW - Phosphines, P-stereogenic AB - A review. This account summarizes our attempts to develop metal-catalyzed asym. syntheses of P-stereogenic phosphines. While such phosphines undergo pyramidal inversion slowly at room temp., inversion is rapid in metal-phosphido complexes (M-PR2). These observations were the basis for catalytic, dynamic kinetic resoln. processes in which racemic secondary phosphines [PR(R')H] were converted into enantioenriched tertiary phosphines [PR(R')(R'')] by platinum-catalyzed asym. hydrophosphination of acrylonitrile or related Michael acceptors, by palladium-catalyzed asym. phosphination of aryl iodides using secondary phosphines or phosphine-boranes, and by platinum-catalyzed asym. alkylation of secondary phosphines. The key intermediates were diastereomeric phosphido complexes with chiral ancillary ligands (Ln*-M-PRR'). Their relative rates of P-inversion and phosphorus-carbon bond formation controlled the enantioselectivity of product formation, whether the phosphorus-carbon bonds were formed by reductive elimination (for Pd), or by the reaction of a platinum-phosphido complex with an electrophile (an alkene in hydrophosphination, or a benzyl bromide in alkylation). The results of mechanistic studies and their use in the design of improved catalytic reactions are described. JO - Synlett ER - TY - JOUR AU - Grajewska, A. AU - Rozwadowska, M.D. PY - 2007 TI - Stereoselective Synthesis of Cytoxazone and Its Analogs SP - 803-13 KW - Cytoxazone, synthesis AB - A review. A variety of synthetic routes to (-)-cytoxazone, a cytokine modulator isolated from Streptomyces cultures, its stereoisomers and its regioisomers were reviewed. JO - Tetrahedron: Asymmetry VL - 18 ER - TY - JOUR AU - Greaves, T.L. AU - Drummond, C.J. PY - 2008 TI - Protic Ionic Liquids: Properties and Applications SP - 206-37 KW - Ionic liquids, protic AB - This review covers the ionicity, physicochem. and thermal properties of protic ionic liqs., along with a description of their applications, and where they have been used, including org. synthesis, chromatog., biol. applications, fuel cells, explosives, and, very recently, industrial lubricants. JO - Chemical Reviews VL - 108(1) ER - TY - JOUR AU - Grobelny, Z. AU - Stolarzewicz, A. AU - Maercker, A. PY - 2007 TI - Stepwise Two-Electron-Transfer Reduction of Cyclic Ethers and Lactones with Alkalide K-, K+(15-Crown-5)2 SP - 1126-34 KW - Lactones, with potassium anions Ethers, cyclic, with K anions AB - A review. The potassium anion possesses two valence electrons in its outer orbital. These two electrons might be transferred to an acceptor mol. simultaneously or stepwise. The stepwise mechanism had been stated till now exptl. only for the reaction of alkalide K-, K+(18-crown-6) with phenylacetylperoxide. A concept of this review was to ascertain if that mechanism has a more general character. Reactions of potassium anions of alkalide K-, K+(15-crown-5)2 with some cyclic ethers and lactones of different ring size were selected for that purpose. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Guillena, G. AU - Najera, C. AU - Ramon, D.J. PY - 2007 TI - Enantioselective Direct Aldol Reaction: The Blossoming of Modern Organocatalysis SP - 2249-93 KW - Aldol reaction, direct, enantioselective AB - A review discusses a plethora of organocatalytic systems used for intermol. and intramol. direct enantioselective aldol reactions and allowing to reach extraordinary levels of efficiencies. Several modifications have been introduced to overcome some of the initial drawbacks of simple (S)-proline, such as long reaction times, high catalyst loading, excess of reagents, etc., improving the expectations for use of these catalysts in large scale synthesis. Thus, various L-proline JO - Tetrahedron: Asymmetry VL - 18 ER - TY - JOUR AU - Gunanathan, C. AU - Ben-David, Y. AU - Milstein, D. PY - 2007 TI - Direct Synthesis of Amides from Alcohols and Amines with Liberation of H2 SP - 790-2 KW - Amides, direct synthesis AB - Given the widespread importance of amides in biochem. and chem. systems, an efficient synthesis that avoids wasteful use of stoichiometric coupling reagents or corrosive acidic and basic media is highly desirable. We report a reaction in which primary amines are directly acylated by equimolar amts. of alcs. to produce amides and mol. hydrogen (the only products) in high yields and high turnover nos. This reaction is catalyzed by a ruthenium complex based on a dearomatized PNN-type ligand [where PNN is 2-(di-tert-butylphosphinomethyl)-6- (diethylaminomethyl)pyridine], and no base or acid promoters are required. Use of primary diamines in the reaction leads to bis-amides, whereas with a mixed primary-secondary amine substrate, chemoselective acylation of the primary amine group takes place. The proposed mechanism involves dehydrogenation of hemiaminal intermediates formed by the reaction of an aldehyde intermediate with the amine. JO - Science VL - 317(5839) ER - TY - JOUR AU - Hamid, M.H.S.A. AU - Slatford, P.A. AU - Williams, J.M.J. PY - 2007 TI - Borrowing Hydrogen in the Activation of Alcohols SP - 1555-75 KW - Alcohols, activation Amines, from alcohols AB - A review. Alcs. can be temporarily converted into carbonyl compds. by the metal-catalyzed removal of hydrogen. The carbonyl compds. are reactive in a wider range of transformations than the precursor alcs. and can react in situ to give imines, alkenes, and .a.-functionalized carbonyl compds. The metal catalyst, which had borrowed the hydrogen, then returned it to the transformed carbonyl compd., leading to an overall process in which alcs. can be converted into amines, compds. contg. C-C bonds and .b.-functionalized alcs. JO - Advanced Synthesis & Catalysis VL - 349 ER - TY - JOUR AU - Harada, T. AU - Kusukawa, T. PY - 2007 TI - Development of Highly Enantioselective Oxazaborolidinone Catalysts for the Reactions of Acyclic .a.,.b.-Unsaturated Ketones SP - 1823-35 KW - Oxazaborolidinone catalysts, unsaturated ketones AB - A review. Chiral Lewis acid catalysis for ketones is one of the active areas in enantioselective reactions to expand the scope of substrates previously limited to aldehydes and bidentate carbonyl compds. In this account, we describe the development of new oxazaborolidinone (OXB) catalysts derived from allo-threonine for asym. Mukaiyama-Michael and Diels-Alder reactions of acyclic .a.,.b.-unsatd. ketones. The scope of these reactions is outlined with particular emphasis on the origin of the enantioselective activation by the oxazaborolidinone catalysts. JO - Synlett ER - TY - JOUR AU - Hierso, J.-C. AU - Smaliy, R. AU - Amardeil, R. AU - Meunier, P. PY - 2007 TI - New Concepts in Multidentate Ligand Chemistry: Effects of Multidentarity on Catalytic and Spectroscopic Properties of Ferrocenyl Polyphosphines SP - 1754-69 KW - Ferrocenyl polyphosphines AB - A review. This tutorial review devoted to ligand chem. deals with the design and properties of ferrocenyl polyphosphines, an original class of multidentate ligands. The development of a varied library of ferrocenyl tetra-, tri- and diphosphine ligands is reviewed. The multidentate nature of these species has led to unique spectroscopic and catalytic properties, in which the spatial proximity of phosphorus atoms is crucial. Regarding their catalytic applications, the key issues of catalyst longevity and ultralow catalyst loadings are discussed. Another part is concerned with fundamental advances gained in phys. chem. for structure elucidation by the study of the intriguing "through-space" NMR spin-spin J couplings existing within several of these polyphosphines. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Huynh, M.H.V. AU - Meyer, T.J. PY - 2007 TI - Proton-Coupled Electron Transfer SP - 5004-64 KW - Electron transfer, proton-coupled AB - A review. Proton-Coupled Electron Transfer (PCET) describes reactions in which there is a change in both electron and proton content between reactants and products. It originates from the influence of changes in electron content on acid-base properties and provides a mol.-level basis for energy transduction between proton transfer and electron transfer. A review with 855 refs. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Iesce, M.R. AU - Cermola, F. AU - Rubino, M. PY - 2007 TI - Photooxygenation of Non-Aromatic Heterocycles SP - 1053-75 KW - Heterocycles, Si, Ge, Te, photooxygenation AB - A review. Photooxygenation of non-arom. heterocycles and cyclic compds. contg. non-usual heteroatoms, namely silicon, germanium, and tellurium was reviewed. All three types of photooxygenation (Types I-III) can take place. Moreover the heteroatom can be frequently involved endorsing electron-transfer reactions which turn out to be the main pathways, even in singlet oxygen oxygenation. A vast collection of novel and unexpected products are often formed, sometimes in a stereocontrolled manner. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Inai, Y. AU - Komori, H. AU - Ousaka, N. PY - 2007 TI - Control of Helix Sense in Protein-Mimicking Backbone by the Noncovalent Chiral Effect SP - 191-202 KW - Peptomimetics, helix AB - A review. The authors have reviewed their previous work regarding induction or control of a peptide helix sense through chiral stimulus to the peptide chain terminus. An optically inactive 310-helix designed mainly with unusual .a.-amino acid residues was commonly employed. Such an N-terminal-free peptide generates a preferred helix sense by chiral acid mol. A helix sense pre-directed in chiral sequence is also influenced or controlled by the chiral sign of such external mol. Here JO - Chemical Record VL - 7 ER - TY - JOUR AU - Iriondo-Alberdi, J. AU - Greaney, M.F. PY - 2007 TI - Photocycloaddition in Natural Product Synthesis SP - 4801-15 KW - Photocyclization, natural product synthesis AB - A review. The application of photocycloaddn. to natural product synthesis continues to produce innovative and effective strategies for key bond constructions in the complex mol. environment. This micro-review surveyed the recent literature for examples that illustrate the power and versatility of photocycloaddn. chem. drawing from [2 + 2], [3 + 2], [4 + 2], [5 + 2] and [4 + 4] reactions. The discussion was confined to natural product syntheses, and included photocycloaddn. key steps in both completed routes and those in progress. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Ishida, T. AU - Haruta, M. PY - 2007 TI - Gold Catalysts : Towards Sustainable Chemistry SP - 7154-6 KW - Gold catalysis, alcohol oxidation Alcohol oxidation, with Au AB - A review. Polymer-supported gold nanoparticles are becoming popular as catalysts for the selective oxidn. of alcs. using mol. oxygen under moderate conditions. Appropriate selection of the polymer substrates, functional groups, size of the gold particles, and solvents leads to higher catalytic activities than with gold catalysts supported on metal oxides or on activated carbon. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Jensen, H.H. AU - Pedersen, C.M. AU - Bols, M. PY - 2007 TI - Going to Extremes: "Super" Armed Glycosyl Donors in Glycosylation Chemistry SP - 7576-82 KW - Glycosylation AB - A review with refs. This concept article gives an overview of stereoelectronic effects in monosaccharide systems and how these can be used to dramatically enhance the reactivity of glycosyl donors in oligosaccharide synthesis. JO - Chemistry--A European Journal VL - 13 ER - TY - BOOK AU - Kappe, C.O. AU - Stadler, A. AU - Eds PY - 2005 BT - Microwaves in Organic and Medicinal Chemistry CY - Weinheim, Germany PB - Wiley-VCH SP - 410 KW - Microwaves, medicinal chemistry, book ER - TY - JOUR AU - Kawase, T. PY - 2007 TI - The Synthesis and Physicochemical and Supramolecular Properties of Strained Phenylacetylene Macrocycles SP - 2609-26 KW - Phenylacetylene macrocyles AB - A review. Strained phenylacetylene macrocycles, cyclic [3]- and [4]metaphenylacetylenes ([n]CMPAs) and methoxy derivs., and cyclic [5]- to [9]paraphenylacetylenes ([n]CPPAs) were prepd. using a strategy based on the McMurry coupling reaction. The physicochem. and supramol. properties of these substances were detd. Interestingly, apart from [3]CMPAs, compds. in these series possess preorganized three-dimensional cavities. JO - Synlett ER - TY - JOUR AU - Kienle, M. AU - Dubbaka, S.R. AU - Brade, K. AU - Knochel, P. PY - 2007 TI - Modern Amination Reactions SP - 4166-76 KW - Amination Amines, functionalized, synthesis Amines, diaryl-, synthesis AB - A review. The synthesis of functionalized arom. and heteroarom. amines has attracted much interest due to their importance as building blocks for pharmaceuticals, polymers, or materials. In this microreview, new developments involving palladium-, nickel-, and copper-catalyzed amination reactions are discussed. The synthesis of functionalized secondary amines or diarylamines by addn. of polyfunctionalized arylmagnesium reagents to nitroarenes or arylazo tosylates is also presented. Finally, primary, secondary, and tertiary amines prepd. by the oxidative coupling of polyfunctional lithium amidocuprates using chloranil as oxidant are highlighted. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Klosin, J. AU - Landis, C.R. PY - 2007 TI - Ligands for Practical Rhodium-Catalyzed Asymmetric Hydroformylation SP - 1251-9 KW - Bis-phosphite ligands Hydroformylation, with Rh, ligands AB - A review. Bis-phosphite and bis-phosphine ligands for asym. hydroformylation reactions were evaluated. Bis-phosphite ligands lead, in general, to high regioselectivities across a range of substrates while good enantioselectivities are limited to only a few examples. Bis-phospholane-type ligands, such as bis-diazaphospholanes and bis-phospholanes, can lead to very high regio- and enantioselectivities for several different substrates. JO - Accounts of Chemical Research VL - 40 ER - TY - BOOK AU - Knochel, P. AU - Ed PY - 2005 BT - Handbook of Functionalized Organometallics: Applications in Synthesis, Vol. 1-2 CY - Weinheim, Germany PB - Wiley-VCH SP - 117 KW - Organometallics, in synthesis, book ER - TY - JOUR AU - Koeck, M. AU - Grube, A. AU - Seiple, I.B. AU - Baran, P.S. PY - 2007 TI - The Pursuit of Palau'amine SP - 6586-94 KW - Marine natural products, palau’amine AB - A review. Since its discovery in 1993, the marine natural product palau'amine has intrigued natural product chemists. Its exotic mol. architecture and purported bioactivity made it an ideal target for synthesis. However, as the years went by and related marine alkaloids were isolated, a skeptical eye was cast on the structure of palau'amine revised. This minireview gives a careful overview of the structural revision and its ramifications to both its biogenesis and total synthesis. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Kotha, S. AU - Lahiri, K. PY - 2007 TI - Synthesis of Diverse Polycyclic Compounds via Catalytic Metathesis SP - 2767-84 KW - Spirocyclic compounds, synthesis Sulfones, cyclic, synthesis Amino acids, .a.-, constrained, synthesis Cyclophanes, via ring-closing metathesis Tetracyclic compounds, synthesis Catalytic metathesis reactions AB - A review. A variety of olefin-metathesis protocols were used to prep. spirocyclic compds., cyclic sulfones, and constrained .a.-amino acid derivs. Conceptually, a new approach to a novel cyclophane ring system was realized via ring-closing metathesis (RCM). Also, tetracyclic compds. related to anthracycline antibiotics were assembled using Claisen rearrangement and RCM as key steps. Further, a sequential use of the Diels-Alder reaction and ring-opening cross-metathesis delivered highly functionalized spiroindane derivs., and trisubstituted benzene derivs. were assembled using Grubbs' catalyst. Finally, the enyne and cross-enyne metathesis sequences were used to prep. several constrained .a.-amino acid derivs. JO - Synlett ER - TY - BOOK AU - Kotschy, A. AU - Timari, G. AU - Eds PY - 2005 BT - Heterocycles from Transition Metal Catalysis: Formation and Functionalization CY - Berlin, Germany PB - Springer KW - Heterocycles, via transition metals, book ER - TY - JOUR AU - Lee, V.Y. AU - Sekiguchi, A. PY - 2007 TI - Aromaticity of Group 14 Organometallics: Experimental Aspects SP - 6596-620 KW - Aromatics, group 14 organometallics AB - A review. The long story of arom. compds. has extended over almost two centuries, since the discovery by Faraday of bicarburet of hydrogen, or C6H6, now called benzene. Since then, the chem. of arom. compds. was developed extensively; this is reflected in the synthesis of novel classes of arom. derivs. including charged species, nonclassical (Moebius, three-dimensional , homo-, metalla-) aroms., and fullerenes. The theory of aromaticity has also undergone a spectacular evolution since the 1st definition of aromaticity by Hueckel; the classification of aromaticity now requires the consideration of versatile criteria: energetic, structural, magnetic, among others. In this Review, the authors discuss the current state of affairs in the chem. of arom. compds. of the heavier Group 14 elements, the latest exptl. achievements, as well as future prospects in the field. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Lee, A.W.M. AU - Chan, W.H. AU - Zhang, S.-J. AU - Zhang, H.-K. PY - 2007 TI - Non Camphor Based Sultam Chiral Auxiliaries SP - 213-28 KW - Sultams, chiral, non-camphor AB - A review. Sulfonamide is an important functional group. Its cyclic version, sultam, has been successfully employed as a chiral auxiliary in controlling diastereoselectivities of numerous org. transformations. The uses of chiral sultams that are not derived from camphor as chiral auxiliaries in asym. syntheses are reviewed. JO - Current Organic Chemistry VL - 11 ER - TY - BOOK AU - Li, J.J. AU - Ed PY - 2005 BT - Name Reactions in Heterocyclic Chemistry CY - Hoboken, N.J. PB - John Wiley SP - 558 KW - Heterocycles, named reactions, book ER - TY - JOUR AU - Li, P. AU - Sergueeva, Z.A. AU - Dobrikov, M. AU - Shaw, B.R. PY - 2007 TI - Nucleoside and Oligonucleoside Boranophosphates: Chemistry and Properties SP - 4746-96 KW - Boranophosphates, nucleosides AB - A review on the chem. and properties of nucleoside boranomonophosphates, boranodiphosphates and boranotriphosphates, dinucleoside and oligonucleoside boranophosphates, nucleoside boranophosphate prodrugs and acyclonucleoside boranophosphate, is reported. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Li, Y.-M. AU - Kwong, F.-Y. AU - Yu, W.-Y. AU - Chan, A.S.C. PY - 2007 TI - Recent Advances in Developing New Axially Chiral Phosphine Ligands for Asymmetric Catalysis SP - 2119-44 KW - Phosphine ligands, axially chiral AB - A review. This review article illustrates the concept and approach for designing new C2-sym. chelating atropisomeric chiral phosphines contg. heterocyclic scaffolds. The versatility in structural modification is highlighted, and that it offers an effective avenue to access chiral ligands of diverse electronic and steric properties for optimization in various catalytic asym. transformations. In this article, the uses of atropisomeric chiral phosphines in some asym. transformations such as hydrogenation and alkyl-/arylation reactions are discussed with ref. to updated literature findings as well as the author's original research. JO - Coordination Chemistry Reviews VL - 251 ER - TY - JOUR AU - Liddle, S.T. AU - Edworthy, I.S. AU - Arnold, P.L. PY - 2007 TI - Anionic Tethered N-Heterocyclic Carbene Chemistry SP - 1732-44 KW - Carbenes, N-heterocyclic AB - A review. Since the discovery of a stable "bottleable" N-heterocyclic carbene (NHC), there has been a spectacular explosion of interest in this ligand class. This interest stems from a desire to understand the fundamentals of the structure and bonding of these systems, but also because of their numerous and emerging applications in small mol. activation, homogeneous catalysis and Lewis acid-catalyzed reactions. In this Tutorial Review, we introduce the reader to NHCs, cover general synthetic methods to prep. anionic tethered NHCs and their metal complexes, and discuss emerging applications in reactivity and catalytic studies. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Lin, Z. PY - 2007 TI - Current Understanding of the .s.-Bond Metathesis Reactions of LnMR + R'-H --> LnMR' + R-H SP - 2280-91 KW - Organometallic chemistry C-H activation Sigma bond activation AB - A review. The metathesis reactions of LnMR + R'-H ? LnMR' + R-H are important fundamental reactions in organometallic chem. and catalysis. The authors reviewed the current understanding of the reactions from a theor. point of view. Selected examples of the reactions involved in catalysis were discussed. JO - Coordination Chemistry Reviews VL - 251 ER - TY - JOUR AU - Lin, L. AU - Liu, X. AU - Feng, X. PY - 2007 TI - Asymmetric Hetero-Diels-Alder Reactions of Danishefsky's and Brassard's Dienes with Aldehydes SP - 2147-57 KW - Danishefsky’s dienes, Diels-Alder AB - A review. The work done by the authors on asym. hetero-Diels-Alder reactions of three Danishefsky's dienes and two Brassard's dienes with aldehydes are summarized. Chiral ligand (R)-1,1'-bi-2-naphthol [(R)-BINOL] and its derivs. complexed with Ti(OPr-i)4 were efficient catalytic systems for the reactions with Danishefsky's dienes, proceeding via a Mukaiyama aldol pathway. Meanwhile, tridentate Schiff base ligands complexed with Ti(OPr-i)4 or Cu(OTf)2 were efficient for the reactions of Brassard's dienes, following the Diels-Alder pathway. JO - Synlett ER - TY - JOUR AU - Liu, S. AU - Han, Y.-F. AU - Jin, G.-X. PY - 2007 TI - Formation of Direct Metal-Metal Bonds from 16-Electron "Pseudo-Aromatic" Half-Sandwich Complexes Cp”M[E2C2(B10H10)] SP - 1543-60 KW - Pseudo-aromatic half sandwich complexes AB - A review. Continuous study on prepn. of multimetallic clusters is stimulated by their rich coordination chem. and promising applications in a variety of interesting fields. Although numerous efforts were devoted to this field, the rational design of homo- and hetero-multimetallic compds. with direct metal-metal bonding supported by 1,2-dicarba-closo- dodecaborane-1,2-dichalcogenolates will still be an important step forward. This tutorial review focuses on the synthetic approach via redox reactions between the pseudo-arom. half-sandwich organometallic carborane precursors Cp''M[E2C2(B10H10)] (Cp'' = .h.5-C5Me5, .h.5-C5H5, .h.5-1,3-tert-Bu2C5H3, .h.6-4-isopropyltoluene) and low-valent transition metal reagents. The tailoring of reaction conditions and the structural information from the resulting products are discussed extensively. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Liu, R. AU - Zhou, X. PY - 2007 TI - Reactivity of the Metal-Cyclopentadienyl (Indenyl, Fluorenyl and Cycloheptatrienyl) Bonds SP - 4424-35 KW - Metal-cyclopentadienyl bonds AB - A review. The focus of this review concerns the reactivity patterns of metal-cyclopentadienyl (indenyl, fluorenyl and cycloheptatrienyl) bonds. The advances in the metal-C(.h.5) insertion chem. demonstrated that the .p.-bonding character provides addnl. reaction opportunities which are not shown by metal-alkyl compds. and these differences are highlighted. JO - Journal of Organometallic Chemistry VL - 692 ER - TY - JOUR AU - Lombardo, M. AU - Trombini, C. PY - 2007 TI - .a.-Hydroxyallylation Reaction of Carbonyl Compounds SP - 3843-79 KW - Alk-1-ene-3,4-diols, synthesis Hydroxyallylation, .a.- of carbonyls AB - A review. This review deals with the straightforward and versatile approach to alk-1-ene-3,4-diols represented by the formal .a.-hydroxyallylation of carbonyl compds. by means of synthetic equiv. of the 1-hydroxyallyl anion. Among the efficient synthetic protocols developed in the last two decades, attention is focused on properly designed 3-oxyallyl organometallic compds. POCH:CHCH2MLn capable of providing stereocontrolled routes to alk-1-ene-3,4-diols. Oxyallyl organometallic compds. POCH:CHCH2MLn, where M is a metal center, L is a JO - Chemical Reviews VL - 107(9) ER - TY - BOOK AU - Loupy, A. AU - Ed PY - 2006 BT - Microwaves in Organic Synthesis: Second, Completely Revised and Enlarged Edition, Vol. 1-2 CY - Weinheim, Germany PB - Wiley-VCH SP - 523 KW - Microwaves, in synthesis, book ER - TY - JOUR AU - Lyaskovskyy, V.V. AU - Voitenko, Z.V. AU - Kovtunenko, V.A. PY - 2007 TI - 11H-Isoindolo[2,1-a]benzimidazoles (review) SP - 253-76 KW - Isoindolobenzimidazoles AB - Review. Data on methods for the synthesis of isoindolo[2,1- a]benzimidazole and its derivs. and their chem. characteristics are reviewed. Data from quantum-chem. calcns. of certain structures are presented. Possible practical applications of the compds. are indicated. JO - Chemistry of Heterocyclic Compounds VL - 43(3) ER - TY - JOUR AU - Ma, J.-A. AU - Cahard, D. PY - 2007 TI - Strategies for Nucleophilic, Electrophilic, and Radical Trifluoromethylations SP - 975-96 KW - Trifluoromethylation AB - A review. Recent advances in the development of new strategies in nucleophilic, electrophilic, and radical trifluoromethylations were reviewed. The emphasis was given to the description of the trifluoromethylating agents, their activation mode, their reaction with carbonyl compds. and derivs., as well as application in asym. synthesis. JO - Journal of Fluorine Chemistry VL - 128 ER - TY - JOUR AU - Mallat, T. AU - Orglmeister, E. AU - Baiker, A. PY - 2007 TI - Asymmetric Catalysis at Chiral Metal Surfaces SP - 4863-90 KW - Metals, chiral modified AB - A review dealing with strategies in heterogeneous enantioselective catalysis, chirally modified metals, and asym. reactions at chirally modified surfaces. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Marciniec, B. PY - 2007 TI - Catalytic Coupling of sp2- and sp-Hybridized Carbon-Hydrogen Bonds with Vinylmetalloid Compounds SP - 943-52 KW - Alkenes, silylative coupling Alkenes, metalation AB - A review. In the account given herein, it has been shown that silylative coupling of olefins, well-recognized as a new catalytic route for the activation of :C-H bond of olefins and :C-Si bond of vinylsilicon compds. with ethylene elimination, can be extended over both other vinylmetalloid derivs. (:C-E) (where E = Ge, B, and others) as well as the activation of =C-H, :Caryl-H, and -O-H bond of alcs. and silanols. This general transformation is catalyzed by transition-metal complexes (mainly Ru and Rh) contg. or initiating TM-H and/or TM-E bonds (inorganometallics). This new general catalytic route for the activation of :C-H and =C-H as well as :C-E bonds called metalative coupling or trans-metalation (cross-coupling, ring-closing, and polycondensation) constitutes an efficient method (complementary to metathesis) for stereo- and regioselective synthesis of a variety of mol. and macromol. compds. of vinyl-E (E = Si, B, and Ge) and ethynyl-E (E = Si and Ge) functionality, also potent organometallic reagents for efficient synthesis of highly .p.-conjugated org. compds. The mechanisms of the catalysis of this de-ethenative metalation have been supported by equimolar reactions of TM-H and/or TM-E with initial substances and reactions with deuterium-labeled reagents. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Marek, I. AU - Simaan, S. AU - Masarwa, A. PY - 2007 TI - Enantiomerically Enriched Cyclopropene Derivatives: Versatile Building Blocks in Asymmetric Synthesis SP - 7364-76 KW - Cyclopropene building blocks AB - A review. Enantiomerically enriched cyclopropene derivs., the smallest possible unsatd. carbocycles, are of great synthetic interest since they serve as versatile building blocks. Their reactivity results from the relief of the ring strain in the small mol. They can be transformed into a wide variety of complex chiral structures and a special emphasis will be directed towards the prepn. of enantiomerically enriched methylene- and alkylidenecyclopropane derivs. The ready availability of a wide range of these chiral entities now provides an excellent opportunity to discover new and unique transformations that can further enrich mainstream synthetic methodol. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Marek, R. AU - Lycka, A. AU - Kolehmainen, E. AU - Sievanen, E. AU - Tousek, J. PY - 2007 TI - 15N NMR Spectroscopy in Structural Analysis: An Update (2001-2005) SP - 1154-205 KW - NMR, 15N AB - Since our previous review article, significant improvements and an array of 15N NMR applications in structural anal. have been published. This report aims to update coverage of improvements in methodol. and various types of applications published over the period 2001 - 2005. Substantial progress in cryogenic probe technol. and the com. availability of JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Marschner, C. PY - 2007 TI - Hafnium: Stepping into the Limelight! SP - 6770-1 KW - C-H activation, Hf Hafnium, bond activation AB - A review. Hafnium, a largely underrated element, showed unexpected C-H and Si-C bond activation chem., which was found during the course of the first synthesis of hafniumbis(silyl)alkyne complexes. As for the case of N2-activation, hafnium proves to be superior to zirconium in this respect. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Martins, M.B. AU - Carvalho, I. PY - 2007 TI - Diketopiperazines: Biological Activity and Synthesis SP - 9923-32 KW - Diketopiperazines Peptides, cyclic, diketopiperazines AB - A review. Only recently have 2,5-diketopiperazines attracted attention due to their biol. properties. Diketopiperazines are the smallest cyclic peptides known. JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Mateo-Alonso, A. AU - Guldi, D.M. AU - Paolucci, F. AU - Prato, M. PY - 2007 TI - Fullerenes: Multitask Components in Molecular Machinery SP - 8120-6 KW - Fullerenes Molecular machines, from fullerenes AB - A review. Mol. machines are mol.-scale devices that carry out predetd. tasks derived from mol. motion. This minireview illustrates how fullerenes can be used as multitask building blocks in mol. machinery, providing new perspectives for fullerenes. Indeed, C60 can be applied as a photo- and electroactive stopper owing to its size, as a probe for mol. motion as a result of its well-defined physicochem. properties, and to induce motion through .p.-.p. interactions. Such mol. motion can be employed to modulate light-driven electron-transfer events, extending the potential applications of mol. machines to the typical fields of application of fullerenes. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - JOUR AU - Mellah, M. AU - Voituriez, A. AU - Schulz, E. PY - 2007 TI - Chiral Sulfur Ligands for Asymmetric Catalysis SP - 5133-209 KW - Sulfur ligands AB - A review discusses the use of nonracemic sulfur-contg. compds. as ligands in asym. synthesis. The formation of carbon-carbon bonds by asym. Grignard coupling, allylic substitution, Diels-Alder and hetero-Diels-Alder, Heck, aldehyde addn., and conjugate addn. reactions, the formation of carbon-hydrogen bonds by asym. carbonyl and alkene redn., and the asym. formation of carbon-nitrogen bonds using sulfur-contg. catalysts is discussed. JO - Chemical Reviews VL - 107 ER - TY - JOUR AU - Mentel, M. AU - Breinbauer, R. PY - 2007 TI - The Witkop-Winterfeldt Oxidation of Indoles SP - 159-76 KW - Indoles, oxidation Quinolones, from indoles AB - A review. In the early 1950s Witkop described in a series of papers that oxidn. of indoles with a variety of oxidn. reagents leads to the formation of quinolones. The mechanism of this reaction involves the oxidative cleavage of the 2,3-double bond of the indole moiety (Witkop oxidn.) followed by a Camps cyclization forming the quinolone ring. Winterfeldt identified conditions which allow a one pot Witkop oxidn./Camps cyclization sequence and applied this strategy for the synthesis of pyrrolo[2,3-c]quinolones starting from 1,2,3,4-tetrahydro- .b.-carbolines. This review gives a comprehensive description of all described examples of this reaction including a definition of scope and limitations and a discussion of the mechanism of this transformation. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Mentel, M. AU - Breinbauer, R. PY - 2007 TI - Electrons as a Reagent in Solid-Phase Organic Synthesis SP - 4283-92 KW - Solid-phase synthesis, electron transfer reactions AB - A review. Solid-phase org. synthesis (SPOS) has become an important tool for the high-throughput synthesis of bioactive mols. or new catalysts. The main advantage of this approach is the covalent attachment of a substrate to an insol. support, enabling reaction workup through simple filtration. However, the heterogeneous nature of SPOS imposes limitations on the org. reactions applicable on solid phase. Electron-transfer reactions and electroorg. synthesis are reaction types that have not yet received much attention in this context. In this review the current status of electron-transfer reactions carried out on solid phase is described and future developments are discussed. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Meyer, C.D. AU - Joiner, C.S. AU - Stoddart, J.F. PY - 2007 TI - Template-directed Synthesis Employing Reversible Imine Bond Formation SP - 1705-23 KW - Imines, in template directed synthesis AB - A review. The imine bond formed by the reversible condensation of an amine and an aldehyde and its applications as a dynamic covalent bond in the template-directed synthesis of mol. compds., is the focus of this tutorial review. Template-directed synthesis - or expressed another way, supramol. assistance to covalent synthesis - relies on the use of reversible noncovalent bonding interactions between mol. building blocks in order to preorganize them into a certain relative geometry as a prelude to covalent bond formation to afford the thermodynamically preferred product. The use of this so-called dynamic covalent chem. (DCC) in templated reactions allows for an addnl. amt. of reversibility, further eliminating potential kinetic products by allowing the covalent bonds that are formed during the template-directed reaction to be proofread for errors, thus making it possible for the reaction to search out its thermodn. min. The marriage of template-directed synthesis with DCC has allowed chemists to construct an increasingly complex collection of compds. from relatively simple precursors. This new paradigm in org. synthesis requires that each individual piece in the mol. self-assembly process is preprogrammed so that the multiple recognition events expressed between the pieces are optimized in a highly cooperative manner in the desired product. It offers an extremely simple way of making complex mech. interlocked compds., such as catenanes, rotaxanes, suitanes, Borromean rings and Solomon knots from relatively simple precursors. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Miyabe, H. AU - Takemoto, Y. PY - 2007 TI - Enantioselective Radical Cyclizations: A New Approach to Stereocontrol of Cascade Reactions SP - 7280-6 KW - Cascade radical cyclization, enantioselective AB - A review discusses the research of the Miyabe and Takemoto groups on the stereoselective and enantioselective cascade radical cyclizations of unsatd. hydroxamates in the presence of nonracemic ligands and Lewis acid catalysts to give nonracemic satd. heterocycles, particularly ?-lactams. JO - Chemistry A European Journal VL - 13 ER - TY - JOUR AU - Mori, M. PY - 2007 TI - Regio- and Stereoselective Synthesis of Tri- and Tetrasubstituted Alkenes by Introduction of CO2 and Alkylzinc Reagents into Alkynes SP - 4981-93 KW - Alkenes, tetrasubstituted, from alkynes Carboxylation, alkylative AB - A review. Carbon dioxide (CO2) is a useful C-1 unit resource in synthetic org. chem. It was known that a low-valent nickel complex could coordinate to CO2 to form an oxanickelacyclopropane, which reacts with a terminal alkyne to form an oxanickelacyclopentene. Transmetalation of the oxanickelacyclopentene with an alkylzinc reagent gives a trisubstituted alkene in high yield after hydrolysis. A novel synthetic method for heterocycles from terminal alkynes contg. suitably positioned heteroatoms was developed, using this alkylative carboxylation followed by a hetero-Michael reaction. Using this procedure, the synthesis of JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Murphy, P.V. PY - 2007 TI - Peptidomimetics, Glyco-mimetics and Scaffolds from Carbohydrate Building Blocks SP - 4177-87 KW - Peptidomimetics Glyco-mimetics AB - A review with refs. Saccharides, due to their high d. of functional groups and availability as chiral building blocks are scaffolds for bioactive compd. discovery. Pyranosides and imino-sugar-based peptidomimetics have been synthesized as ligands for somatostatin receptors and HIV protease. The synthesis of poly-hydroxylated macrolides related to natural products and cyclophanes has been achieved from carbohydrate fragments with a view to investigation of their potential as scaffolds. In addn., the trajectory of arom. systems grafted to saccharides have been studied and this has led to the synthesis of probes for the study of carbohydrate protein interactions. These compds. include geometrically diverse bivalent glyco-mimetics derived from scaffolds that are hybrids of sugars and arom. groups. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Mutai, T. AU - Araki, K. PY - 2007 TI - Fluorescent Oligopyridines and Their Photo-functionality as Tunable Fluorophores SP - 195-211 KW - Fluorescent oligopyridines Oligopyridines, fluorescent AB - A review. Oligopyridines connected through the 2- and 6- positions have long been the subject of continuing interest because of their high ability to interact with metal ions and/or other mols., and their transition-metal complexes have been intensely studied for decades because of their characteristic photophys. properties. However, relatively little was known in regard to the photophys. and photo-functional properties of oligopyridine derivs. From the late 1990s, fluorescent oligopyridines have been of considerable interest as tunable fluorophores by intermol. interaction, and the design and synthesis of novel oligopyridine derivs. and their application to fluorescent sensors has increasingly been studied. Recent developments of fluorescent oligopyridines and their photo-functionality are reviewed. JO - Current Organic Chemistry VL - 11 ER - TY - JOUR AU - Najera, C. AU - Sansano, J.M. PY - 2007 TI - Catalytic Asymmetric Synthesis of .a.-Amino Acids SP - 4584-671 KW - Amino acids, .a.-, synthesis AB - A review. The authors have compiled literature (up to 2005) devoted to catalytic enantioselective synthesis of .a.-amino acids in this detailed and comprehensive review. The asym. synthesis methodol. is organized into four sections: enantioselective introductions of the .a.-hydrogen, the .a.-amino group, the .a.-side chain and the carboxy group. JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Neugebauer, J. PY - 2007 TI - Induced Chirality in Achiral Media-How Theory Unravels Mysterious Solvent Effects SP - 7738-40 KW - Chiral solvent effect AB - A review. Quantum chem. investigations show that chiroptical properties can originate mainly from a chiral solvent shell rather than from the chiral solute. By using this approach it is possible to explain, for example, why the optical rotation of (S)-methyloxirane is pos. in water, but has a relatively strong neg. value in benzene. JO - Angewandte Chemie, International Edition VL - 46 ER - TY - BOOK AU - Olah, G.A. AU - Klumpp, D.A. AU - Eds PY - 2008 BT - Superelectrophiles and Their Chemistry CY - Hoboken, N.J. PB - John Wiley SP - 301 KW - Superelectrophiles, book ER - TY - JOUR AU - Oueslati, I. PY - 2007 TI - Calix(aza)crowns: Synthesis, Recognition, and Coordination. A Mini Review SP - 10840-51 KW - Calix(aza)crowns Calixarenes, azacrown AB - A review. Attaching azacrown bridges on calixarene platform generates calix(aza)crown family. This article reviews synthetic routes for their design and discusses their ion-binding properties by means of coordination and stability consts. JO - Tetrahedron VL - 63 ER - TY - BOOK AU - Overman, L.E. AU - Ed PY - 2007 BT - Organic Reactions, Vol. 69 CY - Hoboken, N.J. PB - John Wiley KW - Dioxirane oxidation, book Fluorination, N-F, book ER - TY - JOUR AU - Ozturk, T. AU - Ertas, E. AU - Mert, O. PY - 2007 TI - Use of Lawesson's Reagent in Organic Syntheses SP - 5210-78 KW - Lawesson's reagent Sulfonation AB - A review. Lawesson's reagent has now been an indispensable reagent for sulfur chem. particularly for converting almost all kinds of oxo groups to thios, which are important functional groups to perform various org. reactions or to use them as end products in material, medicinal, etc. chem. Lawesson's reagent fast and slow reactions toward the functional groups such as alcs., P:Os, amides, ketones, and esters provide the synthetic chemists with a tool of designing their synthetic methodol. accordingly. Moreover, LR is widely applied for the synthesis of almost all kinds of heterocyclic compds. incorporating sulfur atom(s). JO - Chemical Reviews VL - 107(11) ER - TY - JOUR AU - Painter, T.O. AU - Brummond, K.M. PY - 2006 TI - The Direct Proline-Catalyzed Enantioselective Aza-Diels-Alder Reaction: From Development to Use in Natural Product Synthesis SP - 377-84 KW - Aza-Diels-Alder reaction AB - A review with commentary on the title research of A. Cordova (2004), H. Sunden, et al. (2005), and A. Gagnon and S. J. Danishefsky (2006). JO - Chemtracts VL - 19 ER - TY - JOUR AU - Pal, R. AU - Ghosh, S.C. AU - Chandra, K. AU - Basak, A. PY - 2007 TI - Synthesis of .b.-Lactams Using the Kinugasa Reaction SP - 2321-30 KW - Lactams, .b.-, Kinugasa synthesis AB - A review. The development of new strategies for the synthesis of .b.-lactams and their derivs. remains at the forefront of org. synthesis. The copper(I)-catalyzed cycloaddn. of a terminal alkyne and a nitrone, the Kinugasa reaction, leading to the formation of a .b.-lactam has recently drawn to the attention of org. chemists because of its wide scope as well as interesting mechanism. This report aims to give an account of developments in this area with particular emphasis on asym. examples. JO - Synlett ER - TY - JOUR AU - Pellissier, H. PY - 2007 TI - Asymmetric Organocatalysis SP - 9267-331 KW - Organocatalysis, asymmetric AB - A review with 337 refs. discusses the application of organocatalysts in asym. org. synthesis. The article is divided into 3 major sections (nucleophilic addn. to electron deficient carbon-carbon double bonds, nucleophilic addn. to carbon-oxygen double bonds, and nucleophilic addn. to carbon-nitrogen double bonds), which are further subdivided according to the different types of reactions (Michael reactions, aldol reactions, Mannich reactions, etc.). JO - Tetrahedron VL - 63 ER - TY - JOUR AU - Piccialli, V. PY - 2007 TI - Oxidative Cyclization of Dienes and Polyenes Mediated by Transition-metal-oxo Species SP - 2585-607 KW - Dienes, oxidative cyclization AB - A review. During the last forty years, several groups have reported results concerning the oxidative cyclization of polyenes, mostly dienes, with transition-metal-oxo species such as permanganate, ruthenium tetroxide, perruthenate and osmium tetroxide, but only recently has a systematic study of some of these processes been undertaken. The formation in a single step of THF, polytetrahydrofuran, tetrahydropyran and oxepane products with complete relative stereocontrol, and the unique postulated mechanisms, render these processes very appealing from both the synthetic and theor. points of view. Recent synthetic applications of these oxidative transformations have highlighted their usefulness. This review summarizes the state of the art in this field, in an attempt to provide a comprehensive view of these processes. Some similarities between the chem. of ruthenium tetroxide and rhenium(VII)-oxo species are highlighted. JO - Synthesis ER - TY - JOUR AU - Prakash, G.K.S. AU - Hu, J. PY - 2007 TI - Selective Fluoroalkylations with Fluorinated Sulfones, Sulfoxides, and Sulfides SP - 921-30 KW - Fluoroalkylations, with sulfones AB - A review. Efficient fluoroalkylations have been proven to be a highly useful strategy for the synthesis of bioactive fluorine-contg. compds. and other materials. The design and use of a single category of reagents for multiple synthetic goals are much more attractive to preparative org. chemists. In this Account, we show how we have succeeded in the nucleophilic trifluoromethylation, difluoromethylation, difluoromethylenation, (phenylsulfonyl)difluoromethylation, (phenylthio)difluoromethylation, and monofluoromethylation as well as radical (phenylsulfonyl)difluoromethylation and electrophilic difluoromethylation by using fluorinated sulfones, sulfoxides, sulfides, or fluorinated sulfonium salts. The chem. not only provides practically powerful synthetic methods, but the mol. design concept that we have developed may also be adopted to tackle other related chem. problems. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Ramon, D.J. AU - Yus, M. PY - 2007 TI - Chiral Ligands with an Isoborneol-10-sulfonamide Structure: A Ten-year Odyssey SP - 2309-20 KW - Isoborneolsulfonamide ligands AB - A review. The isoborneol-10-sulfonamide unit represents a new type of chiral structure that was successfully prepd. and used in different reactions of organometallic addn. to aldehydes and ketones. The obtained results were excellent in some cases, and this type of ligand is unique as it is able to promote the enantioselective addn. of dialkylzinc reagents to simple ketones. The scope of these catalyzed reactions, together with some synthetic applications, is outlined. Refs. to important related work from others are also included. JO - Synlett ER - TY - BOOK AU - Ramsden, C.A. AU - Ed PY - 2007 BT - Compounds with Two Carbon-Heteroatom Bonds. [In: Sci. Synth., 2007; 31a] CY - Stuttgart, Germany PB - Georg Thieme Verlag SP - 1181 KW - Heterocycles, two heteroatoms, book ER - TY - JOUR AU - Rashatasakhan, P. AU - Harmata, M. PY - 2006 TI - Chiral Nitrenes from Sulfonimidamides SP - 143-51 KW - Nitrenes, chiral, from sulfonimidamides AB - A review with commentary on research by L. Deca et al ( 2004) and by F. Robert-Paillard et al (2004-2006). JO - Chemtracts VL - 19 ER - TY - JOUR AU - Recupero, F. AU - Punta, C. PY - 2007 TI - Free Radical Functionalization of Organic Compounds Catalyzed by N-Hydroxyphthalimide SP - 3800-42 KW - N-hydroxyphthalimide, C-H activation C-H activation, N-hydroxyphthalimide Phthalimido-N-oxyl radical AB - A review. A new organocatalyst, N-hydroxyphthalimide (NHPI), has recently been introduced as an effective system for C-H activation by hydrogen abstraction. It acts as a precursor of the phthalimido-N-oxyl (PINO) radical, which is the effective abstracting species in all of the free radical processes mediated by this N-hydroxy deriv. E.g., NHPI has been used to catalyze the oxidn. of many different classes of org. compds. JO - Chemical Reviews VL - 107(9) ER - TY - JOUR AU - Richardson, S.K. AU - Howell, A.R. PY - 2007 TI - Synthesis and Reactions of 2-Alkylidene Thiiranes and Thietanes SP - 2755-78 KW - Thiiranes, alkylidenes Thietanes, alkylidenes AB - This review covers the synthesis and applications of three- and four-membered sulfur-contg. rings with adjacent exocyclic unsatn. Alkylidene thiiranes have been of largely theor. interest with few applications. Conversely, alkylidene thietanes and dithietanes have been JO - Synthesis ER - TY - JOUR AU - Risseeuw, M.D.P. AU - Overhand, M. AU - Fleet, G.W.J. AU - Simone, M.I. PY - 2007 TI - A Compendium of Sugar Amino Acids (SAA): Scaffolds, Peptide- and Glyco-Mimetics SP - 2001-10 KW - Sugar amino acids Peptidomimetics, sugar amino acids AB - A review. Sugar amino acids (SAAs) are carbohydrate derivs. bearing both amino and carboxylic acid functionalities. SAAs are very versatile conformationally biased building blocks amenable to serve as glyco- or peptidomimetics. The stereochem. arrangement of the substituents of the sugar ring, its ring-size as well as the presence of addnl. functional groups, provide a plethora of possible combinations. In this overview, the structures of oxygen heterocylic SAAs that have been reported thus far are provided, having 3, 4, 5, 6-membered rings as well as several bicyclic counterparts. JO - Tetrahedron: Asymmetry VL - 18 ER - TY - JOUR AU - Roseblade, S.J. AU - Pfaltz, A. PY - 2007 TI - Iridium-Catalyzed Asymmetric Hydrogenation of Olefins SP - 1402-11 KW - Alkenes, asymmetric hydrogenation, with Ir AB - A review. Asym. hydrogenation is one of the most important catalytic methods for the prepn. of optically active compds. For a long time the range of olefins that could be hydrogenated with high enantiomeric excess was limited to substrates bearing a coordinating group next to the C=C bond. The authors found a new class of catalysts, iridium complexes with chiral P, N ligands, that overcome these limitations. For a wide range of unfunctionalized olefins, excellent enantioselectivities could be achieved. Because these catalysts do not require the presence of any particular functional group in the substrate, they considerably broaden JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Rosillo, M. AU - Dominguez, G. AU - Perez-Castells, J. PY - 2007 TI - Chromium Arene Complexes in Organic Synthesis SP - 1589-604 KW - Chromium arene complexes AB - A review. The complexation of an arene to a chromium tricarbonyl unit changes its chem. behavior, giving rise to unprecedented transformations. The electron-withdrawing effect of the unit allows efficient nucleophilic attack (SNAr and dearomatization reactions), stabilizes neg. charges in benzylic positions, and activates CAr-halogen bonds for cross-coupling reactions. In addn., the Cr(CO)3 moiety exerts great facial control so it can be used as an auxiliary that can easily be removed. The 1,2- and 1,3-unsym. disubstituted complexes are planar chiral and there are various ways to prep. them in enantiomerically pure form. Planar chiral chromium complexes are becoming useful intermediates and ligands for asym. catalysis. This mature field of organometallic chem. has given rise to several synthetic applications of chromium arene complexes in the synthesis of natural products. This chem. is overviewed in this tutorial review, giving special attention to the most recent and outstanding contributions in the area. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Satoh, T. PY - 2007 TI - Recent Advances in the Chemistry of Magnesium Carbenoids SP - 1561-72 KW - Magnesium carbenoids AB - A review. This tutorial review deals with recent advances in the chem. and synthetic use of Mg carbenoids. The reactivity of traditional carbenoids (.a.-haloalkyllithium species) was successfully reduced by using Mg as the metal instead of Li. Properties of these relatively stable carbenoids, Mg carbenoids, were widely studied and the Mg carbenoids have very interesting reactivity toward several nucleophiles. The Mg carbenoids, Mg cyclopropylidenes, Mg alkylidene carbenoids, and Mg .b.-oxido carbenoids are generated from .a.-chloroalkyl (or .a.-chloroalkenyl) aryl sulfoxides with a Grignard reagent at low temp. by sulfoxide-Mg exchange reaction. The stability of the generated Mg carbenoids and several new reactions based on the electrophilicity of the Mg carbenoids, including 1,3-CH insertion, are reviewed. Mg carbenoids open up the new world of the chem. of carbenoids. JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Saudan, L.A. PY - 2007 TI - Hydrogenation Processes in the Synthesis of Perfumery Ingredients SP - 1309-19 KW - Hydrogenation, perfume synthesis AB - A review. Homogeneous catalytic hydrogenation has played an important role in the development of modern org. synthesis. Indeed, the discovery of highly regio- and stereoselective catalysts for C=C and C=O bonds redns. has allowed the efficient synthesis of optically active compds. As the fragrance industry has turned to synthetic ingredients to fulfill the need for novel, cost-effective, and environment-friendly products, the use of catalytic processes are more and more in demand. In this review, the author highlights the application of catalytic hydrogenation in the synthesis of fragrance ingredients. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Schaefer, M. AU - Drayue, M. AU - Springer, A. AU - Zacharias, P. AU - Meerholz, K. PY - 2007 TI - Radical Cations in Electrospray Mass Spectrometry: Formation of Open-Shell Species, Examination of the Fragmentation Behavior in ESI-MSn and Reaction Mechanism Studies by Detection of Transient Radical Cations SP - 5162-74 KW - Mass spectrometry, electrospray AB - A review. The ion formation mechanism in electrospray MS is reviewed, with special focus on the electrochem. red/ox reactions responsible for the formation of radical mol. ions. Prerequisites influencing the likelihood of formation and observation of a particular compd. as an open-shell mol. species in ESI-MS (i.e., the structure and the oxidn. potential of the analyte, the solvent and additives) are evaluated. For illustration of the ESI phenomena governing radical cation formation, an ESI-MS study of tetra(aryl)benzidine compds. is presented. The facile formation of abundant radical mol. cations in ESI-MS demonstrates imposingly that the basicity of the analyte's nitrogen atoms is strongly overcompensated by the ability to stabilize unpaired electrons. ESI-MSn spectra of the tetra(aryl)benzidine mol. ions exhibit a characteristic feature in the loss of radicals. This process is the major fragmentation pathway of open-shell mol. precursor ions in their MS2 spectra, and also that even-electron ions in sequential MSn spectra. The collision-induced dissocn. (CID) behavior suggests a general assumption: easily oxidizable compds. (e.g., hydrocarbon polyenes, polycyclic arom. hydrocarbons, porphyrins etc.) generating predominantly mol. radical cations in ESI-MS contradict the even electron rule in ESI-MSn expts. The strong ability to stabilize unpaired electrons in preserved in product ions and makes the formation of open-shell species energetically less demanding. A selection of soln.-phase reaction mechanistic studies in which open-shell intermediates were detected and structurally characterized by ESI-MS and ESI-MSn for mechanistic studies of chem. reaction are critically discussed. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Selina, A.A. AU - Karlov, S.S. AU - Zaitseva, G.S. PY - 2006 TI - Metallocanes of Group 14 Elements. 1. Derivatives of Silicon and Germanium. (Review) SP - 1518-56 KW - Metallocenes, Si and Ge AB - A review. Results on the synthesis of silocanes and germocanes, eight-membered heterocycles with the general formula D(CH2CH2Z)2MXY are analyzed and classified. The chem. behavior of these compds. and the characteristics of the element-nitrogen transannular bond are studied. JO - Chemistry of Heterocyclic Compounds VL - 42(12) ER - TY - JOUR AU - Sellars, J.D. AU - Steel, P.G. PY - 2007 TI - Advances in the Synthesis of Aryltetralin Lignan Lactones SP - 3815-28 KW - Aryltetralin lignan lactones Anticancer agents, podophyllotoxins AB - A review. Etoposide and tenoposide, derivs. of the aryltetralin lignan lactone podophyllotoxin (I), are clin. important anticancer agents. The structure of podophyllotoxin includes four contiguous chiral centers contained within a stereochem. unstable trans-fused tetrahydronaphthalene lactone skeleton. Reflecting this challenging structure and important biol. role there has been long-standing interest in developing efficient stereocontrolled syntheses of this class of natural product. This microreview summarizes the key developments toward this end focusing on more recent developments both from within the authors group and elsewhere. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Serra, S. AU - Fuganti, C. AU - Brenna, E. PY - 2007 TI - Recent Advances in the Benzannulation of Substituted 3-Alkoxycarbonyl-3,5- Hexadienoic Acids and 3-Alkoxycarbonylhex-3-en-5-ynoic Acids to Polysubstituted Aromatics SP - 6782-91 KW - Aromatics, polysubstituted, via benzannulation AB - A review. The benzannulation reactions of substituted 3-alkoxycarbonyl-3,5-hexadienoic and 3-alkoxycarbonylhex-3-en-5-ynoic acids offer a straightforward access to various polysubstituted arom. compds. The process is very flexible, and can be applied to the regiospecific prepn. of oligoaryls, naphthalenes, ring-fused heterocycles, chiral tetrahydronaphthalenes, C-aryl-glycosides and many natural products of different structure. In this Concept article, we highlight the potential of this annulation reaction by illustration of our recent contribution to this field, as well as the studies previous reported by others. JO - Chemistry--A European Journal VL - 13 ER - TY - JOUR AU - Shoji, M. AU - Hayashi, Y. PY - 2007 TI - Chemistry of Epoxyquinols A, B, and C and Epoxytwinol A SP - 3783-800 KW - Epoxyquinols Epoxytwinols AB - A review. The asym. total synthesis of epoxyquinols A, B, and C and epoxytwinol A, and computational anal. of the key biomimetic oxidative dimerization procedure are described. In the first-generation synthesis a HfCl4-mediated diastereoselective Diels-Alder reaction of furan with Corey's chiral auxiliary has been developed. In the second-generation synthesis, a chromatog.-free prepn. of an iodolactone using acryloyl chloride as the dienophile in Diels-Alder reaction of furan and a lipase-mediated kinetic resoln. of a cyclohexenol deriv. have been developed. This second-generation synthesis is suitable for large-scale synthesis. A biomimetic cascade reaction involving oxidn., 6.p.-electrocyclization, and then Diels-Alder dimerization is the key reaction in the formation of the complex heptacyclic structure of epoxyquinols A, B, and C. Epoxytwinol A is synthesized by the cascade reaction involving oxidn., 6.p.-electrocyclization, and formal (4+4) cycloaddn. reactions. A 2H-pyran, generated by oxidn./6- electrocyclization, acts as a good diene, reacting with several dienophiles to afford polycyclic compds. in one step. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Shuklov, I.A. AU - Dubrovina, N.V. AU - Boerner, A. PY - 2007 TI - Fluorinated Alcohols as Solvents, Cosolvents and Additives in Homogeneous Catalysis SP - 2925-43 KW - Fluorinated alcohols AB - This review presents the use of fluorinated alcs. as solvents, cosolvents or additives in homogeneous catalysis. The effect of these particular compds. on efficiency, regioselectivity and stereoselectivity of metal-catalyzed reactions, as well as on reactions mediated by organocatalysts, is described. Where available in several cases, the effect of fluorous alcs. on the catalytic mechanism is analyzed in detail and rationalized by their unique phys. and chem. properties. In most instances, a comparison to the effect of commonly employed solvents is elaborated. JO - Synthesis ER - TY - JOUR AU - Singh, S. AU - Roesky, H.W. PY - 2007 TI - Fluorine Functionalized Compounds of Group 13 Elements SP - 369-77 KW - Organoaluminum fluorides AB - The review gives a short survey of some developments in the synthetic chem. of organoaluminum fluorides. Into the focus is brought the Janus-faced Lewis base-Lewis acid Al compd., group 13 difluorodiorganometalates, fluorine functionalized carbaalane derivs., fluorination of aluminum imide clusters, diamidoaluminum fluoride, and some group 13 .b.-diketiminate mono- and difluorides. JO - Journal of Fluorine Chemistry VL - 128 ER - TY - JOUR AU - Skucas, E. AU - Ngai, M.-Y. AU - Komanduri, V. AU - Krische, M.J. PY - 2007 TI - Enantiomerically Enriched Allylic Alcohols and Allylic Amines via C-C Bond-Forming Hydrogenation: Asymmetric Carbonyl and Imine Vinylation SP - 1394-401 KW - Alcohols, allylic, synthesis Amines, allylic, synthesis Aldehydes, alkyne addition Imines, alkyne addition AB - A review discusses the research of the Krische group and particularly their method for the stereoselective and enantioselective prepn. of allylic alcs. and amines by hydrogenative addn. of alkynes to aldehydes and imines. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Snape, T.J. PY - 2007 TI - Recent Advances in the Semi-Pinacol Rearrangement of .a.-Hydroxy Epoxides and Related Compounds SP - 1823-42 KW - Hydroxy epoxides, semi-pinacol rearrangement Semi-pinacol rearrangement, with .a.-hydroxy epoxides AB - A review. The semi-pinacol rearrangement is fast becoming an extremely reliable reaction in org. synthesis allowing the rapid construction of relatively complex stereodefined products in high yield. Recent advances in asym. synthesis have also enabled enantiopure precursors to partake in the rearrangement showing that extremely high levels of stereospecificity are obsd. In this crit. review recent advances in the semi-pinacol rearrangement over the past 15 years were examd. which demonstrate the extremely high utility of this reaction towards the development of structurally diverse org. building blocks (74 refs.). JO - Chemical Society Reviews VL - 36 ER - TY - JOUR AU - Solinas, A. AU - Taddei, M. PY - 2007 TI - Solid-supported Reagents and Catch-and-Release Techniques in Organic Synthesis SP - 2409-53 KW - Solid supports Catch-and-release synthesis AB - A review. The use of polymer-supported reagents, catalysts and scavengers (and their appropriate combinations) represents a powerful approach for the synthesis of org. compds., using both traditional and parallel soln.-phase methodologies, and it has been of great interest in recent years, esp. in the field of pharmaceutical research. Polymer-supported synthesis circumvents the need to bind the substrate to a solid support, and thereby allows for the reactions to be monitored with familiar anal. techniques. The purpose of this publication is to review the recent synthetic transformations (from 2001) carried out with solid-supported reagents, including the catch-and-release techniques, which represent a hybrid approach in between scavenging and solid-phase synthesis. JO - Synthesis ER - TY - JOUR AU - Takeda, T. PY - 2007 TI - Titanium Carbene Complexes as Useful Tools in Organic Synthesis SP - 24-36 KW - Titanium carbenes Olefin metathesis, Ti carbenes AB - A review. Various titanium carbene complexes are prepd. by the reductive titanation of thioacetals, gem-dihalides, and related organosulfur and organohalogen compds. with the titanocene(II) reagent Cp2Ti[P(OEt)3]2. Alkylidene-, heteroatom-substituted methylidene-, 2-alkenylidene-, 2-alkynylidene-, and vinylidene-titanocenes thus formed are highly reactive toward org. compds. bearing a multiple bond and are employed for a variety of org. transformations such as carbonyl olefination and olefin metathesis. JO - Chemical Record VL - 7 ER - TY - JOUR AU - Takeda, N. AU - Tokitoh, N. PY - 2007 TI - A Bulky Silylene Generated Under Mild Conditions: Its Application to the Synthesis of Organosilicon Compounds SP - 2483-91 KW - Organosilicon compounds AB - A review. By taking advantage of the bulky silylene Tbt(Mes)Si: (1) [Tbt = 2,4,6-(Me3Si)3C6H2, Mes = 2,4,6-Me3C6H2], generated under mild conditions from disilene Tbt(Mes)Si:Si(Mes)Tbt (2) or silylene-isocyanide complex Tbt(Mes)SiCNAr (Ar = C6H2(i-Pr)3-2,4,6, Tbt, Mes* (Mes* = C6H2(t-Bu)3-2,4,6)), the synthesis of a variety of reactive Si compds., such as 2H-azasilirene, 2H-phosphasilirene, vinylsiliranes, silanone (intermediate) and silacyclic compds. contg. chalcogens, was achieved. Some unique reactivities of silylene 1, i.e., [1+2] cyclo-addn. reactions to benzene and naphthalene, a double addn. reaction with CS2 giving a disilacyclobutanethione deriv., and insertion reactions into B-H, B-F, B-Cl, and B-B bonds, were also revealed. JO - Synlett ER - TY - JOUR AU - Terao, J. AU - Kambe, N. PY - 2007 TI - Transition Metal Catalyzed Carbon-Silicon Bond Forming Reactions Using Chlorosilanes Promoted by Grignard Reagents SP - 57-67 KW - Chlorosilanes, C-Si bonds Silylation, with chlorosilanes AB - A review. New catalytic C-Si bond-forming reactions using chlorosilanes are described. These reactions proceed efficiently under mild conditions by the combined use of Grignard reagents and transition metal catalysts, such as Ti, Zr, Ni, and Pd. It is proposed that ate complex intermediates formed by the reaction of transition metals with Grignard reagents play important roles as the active catalytic species. The present study demonstrates the practical use of chlorosilanes in transition metal catalyzed silylation reactions providing convenient methods for allyl- or vinylsilane synthesis. The reaction pathways of these transformations as well as the scope and limitations are discussed. JO - Chemical Record VL - 7 ER - TY - BOOK AU - Tietze, L.F. AU - Eicher, T. AU - Diederichsen, U. AU - Speicher, A. AU - Eds PY - 2007 BT - Reactions and Syntheses in the Organic Chemistry Laboratory CY - Weinheim, Germany PB - Wiley-VCH SP - 582 KW - Synthesis, book ER - TY - BOOK AU - Ulrich, H. AU - Ed PY - 2007 BT - Chemistry and Technology Carbodiimides CY - West Sussex, U. K. PB - John Wiley SP - 294 KW - Carbodiimides, book ER - TY - JOUR AU - van den Bos, L.J. AU - Codee, J.D.C. AU - Litjens, R.E.J.N. AU - Dinkelaar, J. AU - Overkleeft, H.S. AU - van der Marel, G.A. PY - 2007 TI - Uronic Acids in Oligosaccharide Synthesis SP - 3963-76 KW - Uronic acids, in oligosaccharides Oligosaccharides, with uronic acids AB - A review with refs. This Micro-review covers some general strategies for the prepn. of uronic acid residues and their incorporation into anionically charged oligosaccharides. Two distinct strategies can be recognized: (1) glycosylation followed by oxidn., and (2) oxidn. of the monosaccharide building blocks followed by glycosylation. Examples of both strategies are discussed, with a focus on the advantages and disadvantages of the resp. strategies. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Vicario, J.L. AU - Badia, D. AU - Carrillo, L. PY - 2007 TI - Organocatalytic Enantioselective Michael and Hetero-Michael Reactions SP - 2065-92 KW - Michael additions AB - A review of the enantioselective methods reported to date for carrying out conjugate addns. of C- and heteroatom-centered nucleophiles to electron-deficient olefins, using small chiral org. mols. as catalysts, is presented. JO - Synthesis ER - TY - JOUR AU - Vilotijevic, I. AU - Jamison, T.F. PY - 2007 TI - Epoxide-Opening Cascades Promoted by Water SP - 1189-92 KW - Epoxides, cascade opening Tetrahydropyran template Polyethers, ladder AB - Selectivity rules in org. chem. have been inferred largely from nonaq. environments. In contrast, enzymes operate in water, and the chem. effect of the medium change remains only partially understood. Structural characterization of the "ladder" polyether marine natural products raised a puzzle that persisted for 20 years: Although the stereochem. of adjacent tetrahydropyran (THP) cycles would seem to arise from a biosynthetic cascade of epoxide-opening reactions, experience in org. solvents argued consistently that such a pathway would be kinetically disfavored. We report that neutral water acts as an optimal promoter for the requisite ring-opening selectivity, once a single templating THP is appended to a chain of epoxides. This strategy offers a high-yielding route to the naturally occurring ladder core, e.g. I, and highlights the likely importance of aq.-medium effects in underpinning certain noteworthy enzymic selectivities. JO - Science VL - 317(5842) ER - TY - JOUR AU - Wang, Y. AU - Jiang, W. AU - Yan, T. AU - Voth, G.A. PY - 2007 TI - Understanding Ionic Liquids through Atomistic and Coarse-Grained Molecular Dynamics Simulations SP - 1193-9 KW - Ionic liquids, properties AB - A review. Understanding the phys. properties of ionic liqs. (ILs) via computer simulation is important for their potential technol. applications. The goal of IL research is to obtain a unified understanding of the properties of ILs with respect to their underlying mol. structure. From atomistic mol. dynamics simulations, the many-body electronic polarization effect is important for modeling ILs, esp. their dynamics. The multiscale coarse-graining methodol. also was employed to increase the simulation speed by a factor of ?100, thereby making it possible to study the mesoscopic behavior of ILs by computer simulations. With these simulation techniques, ILs with an amphiphilic cation exhibited a spatial heterogeneity due to the aggregation of their nonpolar alkyl tails. This spatial heterogeneity is a key feature in interpreting many phys. phenomena of ILs, such as their heterogeneous self-diffusion and surface layering, as well as their surfactant-like micelles formed in IL/H2O mixts. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Welch, G.C. AU - San Juan, R.R. AU - Masuda, J.D. AU - Stephan, D.W. PY - 2006 TI - Reversible Metal-Free Hydrogen Activation SP - 152-6 KW - Hydrogen activation, metal-free AB - A review of the title research of G. C. Welch, R. R. San Juan, J. D. Masuda and D. W. Stephan (2006) is presented with commentary and 4 refs. JO - Chemtracts VL - 19 ER - TY - JOUR AU - West, D.C. PY - 2006 TI - Recent Progress toward Catalyzed Anti-Selective Mannich-Type Reactions SP - 129-35 KW - Mannich-type reactions, anti-selective AB - A review with commentary on research by S. Mitsumori et al (2006) and by T. Kano et al (2005). JO - Chemtracts VL - 19 ER - TY - JOUR AU - Wolter, F. AU - Schoof, S. AU - Suessmuth, R.D. PY - 2007 TI - Synopsis of Structural, Biosynthetic, and Chemical Aspects of Glycopeptide Antibiotics SP - 143-85 KW - Glycopeptide antibiotics AB - A review. Glycopeptide antibiotics represent a very important group of natural products with regard to medicinal application as antibacterial agents and for cancer treatment. A characteristic for assignment as a glycopeptide antibiotic, next to antibiotic potential, is the modification of the peptide aglycon with various types of carbohydrates. According to this definition, vancomycin (including five subtypes), ramoplanin, bleomycin, mannopeptimycins and salmochelin belong to the family of glycopeptide antibiotics. In this article, an overview is given on the structural aspects, the biosynthesis and the mode of action of glycopeptide antibiotics. Structure-activity relationships of important functional groups contributing to enhanced antibiotic properties are highlighted. Finally, similarities with regard to structural features, the biosynthesis and the modes of actions are discussed. According to current knowledge, glycopeptide antibiotics mostly act as inhibitors of bacterial cell wall biosynthesis. It is to be expected that the actual list of glycopeptides will be continuously extended due to discoveries from ongoing screening programs. JO - Topics in Current Chemistry VL - 267 ER - TY - JOUR AU - Yoshioka, R. PY - 2007 TI - Racemization, Optical Resolution and Crystallization-Induced Asymmetric Transformation of Amino Acids and Pharmaceutical Intermediates SP - 83-132 KW - Amino acids, asymmetric transformations AB - A review. Tanabe Seiyaku has been investigating an efficient optical resoln. method for the prodn. of optically active amino acids since the 1950s. As one of the practical applications of the resoln. methods, we focused on crystn.-induced asym. transformation, with which it is possible to obtain more than 50% of one enantiomer of a racemate. In order to achieve the asym. transformation, an elegant method for racemization of optically active amino acids and their salts was developed. This successful racemization procedure led to efficient and economical prepn. paths for various optically active amino acids by the two crystn.-induced asym. transformations, one of which is a combination of enantiomeric resoln. and simultaneous racemization and the other is a combination of diastereomeric resoln. and simultaneous epimerization. Here, many examples of our studies and recent reports of pharmaceutical intermediates are presented. JO - Topics in Current Chemistry VL - 269 ER - TY - BOOK AU - Zewail, A. AU - Ed PY - 2007 BT - Hydrogen-Transfer Reactions: Vol. 1-2, Physical and Chemical Aspects CY - Weinheim, Germany PB - Wiley-VCH KW - Hydrogen transfer reactions, book ER - TY - JOUR AU - Zhang, W. AU - Chi, Y. AU - Zhang, X. PY - 2007 TI - Developing Chiral Ligands for Asymmetric Hydrogenation SP - 1278-90 KW - Ligands, phosphocyclic Ligands, atropisomeric Ligands, bisphosphine AB - A review. This Account outlines our efforts in ligand development for asym. hydrogenation. The successful development of three classes of ligands is presented, including (1) ligands with phosphocyclic motifs, (2) ligands with atropisomeric backbones, and (3) bisphosphine ligands inspired by the structure of 2,3-O-isopropylidene-2,3-dihydroxyl-1,4- bis(diphenylphosphino)butane (DIOP). With this large ligand toolbox, we have prepd. many pharmaceutically valuable chiral products efficiently. JO - Accounts of Chemical Research VL - 40 ER - TY - JOUR AU - Zhou, Y.-G. PY - 2007 TI - Asymmetric Hydrogenation of Heteroaromatic Compounds SP - 1357-66 KW - Heteroaromatics, asymmetric hydrogenation AB - A review. Asym. hydrogenation of heteroarom. compds. has emerged as a promising new route to satd. or partially satd. chiral heterocyclic compds. In this review, the author outlines recent advances in asym. hydrogenation of heteroarom. compds., including indole, quinoline, isoquinoline, furan, and pyridine derivs., using chiral organometallic catalysts and organocatalysts. JO - Accounts of Chemical Research VL - 40 ER -