10.1021/om030623w.s001
Victor Martinez
Victor
Martinez
Jean-Claude Blais
Jean-Claude
Blais
George Bravic
George
Bravic
Didier Astruc
Didier
Astruc
Coupling Multiple Benzylic Activation of Simple Arenes
by CpFe<sup>+</sup> with Multiple Alkene Metathesis Using Grubbs
Catalysts: An Efficient Carbon−Carbon Bond Formation
Strategy Leading to Polycycles, Cyclophanes, Capsules,
and Polymeric Compounds and Their CpFe<sup>+</sup> Complexes
American Chemical Society
2004
Ru
Grubb
CpFe
FeCp
selectivity
CM metathesis
arene
Multiple Benzylic Activation
allyl
catalyst
2 Cl 2
KOH
RCM
Multiple Alkene Metathesis
benzylic hydrogens
2004-02-16 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Coupling_Multiple_Benzylic_Activation_of_Simple_Arenes_by_CpFe_sup_sup_with_Multiple_Alkene_Metathesis_Using_Grubbs_Catalysts_An_Efficient_Carbon_Carbon_Bond_Formation_Strategy_Leading_to_Polycycles_Cyclophanes_Capsules_and_Polymeric_Compounds_and_Their_C/3349939
The CpFe<sup>+</sup>-induced perallylation of arenes containing benzylic hydrogens in the complexes
[FeCp(η<sup>6</sup>-arene)][PF<sub>6</sub>] using a base and allyl bromide has been improved by using room-temperature conditions and KOH as a base, which simplifies the procedure and brings the
selectivity when some benzylic hydrogens remain. This reaction has been combined with
RCM metathesis of two allyl groups borne by the same benzylic carbon using the Grubbs
catalyst [Ru(CHPh)(PCy<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>] (<b>1</b>) in a few minutes at room temperature and with cross-metathesis (CM) in refluxing dichloroethane using the more efficient second-generation
Grubbs catalyst [Ru(CHPh)(PCy<sub>3</sub>)<sub>2</sub>{C(NMesCH<sub>2</sub>)<sub>2</sub>Cl<sub>2</sub>}] (<b>2</b>). The FeCp<sup>+</sup> tag allows an easy
separation of the product from the catalyst and slows down the CM reaction for steric reasons,
providing selectivity for the RCM reaction. The iron-free polyallyl arenes undergo both RCM
and CM metathesis, and catalysis can also be carried out in the ionic liquid 1-butyl-3-imidazolium hexafluorophosphate as the solvent at 80 °C. CM metathesis of the perallylated
arenes gives organoiron and organic macrocycles, cyclophanes, capsules, and polymers, all
these compounds being conveniently detected by MALDI-TOF mass spectroscopy, which also
gives useful information concerning the advancement of the metathesis reaction and the
purity or mixture of the metathesis products.