%0 Journal Article %A Carmona, Daniel %A Vega, Cristina %A García, Néstor %A Lahoz, Fernando J. %A Elipe, Sergio %A Oro, Luis A. %A Lamata, M. Pilar %A Viguri, Fernando %A Borao, Rosana %D 2006 %T Chiral Phosphinooxazoline−Ruthenium(II) and −Osmium(II) Complexes as Catalysts in Diels−Alder Reactions %U https://acs.figshare.com/articles/journal_contribution/Chiral_Phosphinooxazoline_Ruthenium_II_and_Osmium_II_Complexes_as_Catalysts_in_Diels_Alder_Reactions/3231193 %R 10.1021/om050973d.s008 %2 https://acs.figshare.com/ndownloader/files/5065261 %K BF %K R Ru %K SbF 6 %K PN i Pr %K MeC %K R M %K phosphinooxazoline ligand %K OPOF 2 %K PNOH %K S Os %K phosphinooxazoline chloride complexes %K PNF i Pr %X The synthesis and characterization of optically active phosphinooxazoline chloride complexes (SM and RM)-[(η6-p-MeC6H4iPr)MCl(PN)]A (M = Ru, Os; PN = phosphinooxazoline ligand; A = counteranion) and the derived aqua complexes (RM and SM)-[(η6-p-MeC6H4iPr)M(PN)(H2O)](A)2 are reported. The OPOF2-containing compounds (RM and SM)-[(η6-p-MeC6H4iPr)M(OPOF2)(PNiPr)][PF6] (M = Ru, Os; PNiPr = (4S)-2-(2-diphenylphosphinophenyl)-4-isopropyl-1,3-oxazoline) have been also prepared and characterized. The molecular structures of (SM)-[(η6-p-MeC6H4iPr)MCl(PNiPr)][SbF6] (M = Ru, Os), (SRu)-[(η6-p-MeC6H4iPr)RuCl(PNInd)][SbF6] (PNInd = (3aS,8aR)-2-(2-diphenylphosphinophenyl)-3a,8a-dihydroindane [1,2-d]oxazole), and (RRu)-[(η6-p-MeC6H4iPr)Ru(PNiPr)(H2O)][SbF6] and that of the OPOF2-containing compounds (RRu and SRu)-[(η6-p-MeC6H4iPr)Ru(OPOF2)(PNiPr)][PF6] have been determined by X-ray diffractometric methods. Dichloromethane solutions of the aqua complexes [(η6-p-MeC6H4iPr)M(PN)(H2O)][SbF6]2 are active catalysts for the Diels−Alder reaction between methacrolein and cyclopentadiene. The reaction occurs rapidly at room temperature with good exo:endo selectivity (from 85:15 to 96:4) and moderate enantioselectivity (up to 47%). The intermediate Lewis acid−dienophile compound (RRu and SRu)-[(η6-p-MeC6H4iPr)Ru(PNInd)(methacrolein)][SbF6]2 was isolated, and the molecular structure of the S epimer was determined by diffractometric means. The osmium complexes (SOs and ROs)- [(η6-p-MeC6H4iPr)Os(PN)(H2O)][A]2 (PN = PNiPr, A = SbF6, BF4; PN = PNInd, A = SbF6) evolve to the phenyl-containing compounds (SOs and ROs)-[(η6-p-MeC6H4iPr)OsPh(PN‘)][SbF6] (PN‘ = (4S)-2-(2-hydroxyphenylphosphinophenyl)-4-isopropyl-1,3-oxazoline (PNOHiPr), PN‘ = (3aS,8aR)-2-(2-hydroxyphenylphosphinophenyl)-3a,8a-dihydroindane[1,2d]oxazole] (PNOHInd)) and (SOs and ROs)-[(η6-p-MeC6H4iPr)OsPh(PNFiPr)][BF4] (PNFiPr = (4S)-2-(2-fluorophenylphosphinophenyl)-4-isopropyl-1,3-oxazoline), respectively, in which the phosphinooxazoline ligand incorporates a hydroxy or fluoro functionality. On the basis of spectroscopic and crystallographic observations, a common pathway for these reactions is proposed. %I ACS Publications