| Chiral rhodium(III) and ruthenium(II) complexes were designed to serve as stereoselective catalysts. These complexes contained the bidentate phosphine ligands, 2,2′-bis(diphenylphosphino)-1,1′ -binaphthyl (BINAP), monoxidized BINAP (BINPO), 1,1′ -bis(diphenylphosphino)methane monoxide (dppmO), (1-(diphenylphosphino)ethyl)diphenylphosphine oxide (Ph2PCH(CH3)P(O)Ph2), 2-dicyclohexylphosphino-2 ′-(N,N-dimethylamino)biphenyl (Me2NC 6H4C6H4PCy2), 2-(dicyclohexylphosphino)biphenyl, and 2-(dicyclohexylphosphino)-2′-methylbiphenyl. The catalysts were applied in several stereoselective reactions.; In the hydrosilylation of phenylacetylene, [Cp*Rh((S)-BINAP)](SbF 6)2 was found to generate β-E vinylsilanes preferentially and gave especially high regioselectivity and stereoselectivity with triphenylsilane (>99%).; Each complex catalyzed the asymmetric Diels-Alder reaction of methacrolein with cyclopentadiene in the following ee: [Cp*Rh(( S)-BINAP)](SbF6)2, 51% (S-exo); [(p-cymene)Ru((S)-BINAP)](SbF6) 2, 50% (R-exo); [Cp*Rh((S)-BINPO)](SbF 6)2, 9% (R-exo); [Cp*Rh(η2-Ph 2PCH(CH3)P(O)Ph2-P,O)](SbF 6)2, 21–38% (S-exo); [Ru(η 6:η1-Me2NC6H4C 6H4PCy2-P)(PPh3)](SbF 6)2, ∼20%. Racemic [Cp*Rh(η2-Ph 2PCH(CH3)P(O)Ph2-P,O)](SbF 6)2 catalyzed the reaction via chiral poisoning by (1R)-(+)-camphor and L-proline. Tethered, chiral-at-metal, [Ru(η6:η1-Me2 NC6H4C6H4PCy2- P)(PPh3)Cl]SbF6, which resolved spontaneously upon recrystallization, served as the enantiopure precursor of [Ru(η 6:η1-Me2NC6H4C 6H4PCy2-P)(PPh3)](SbF 6)2.; The asymmetric transfer hydrogenation of 1′-acetonaphthone with 2-propanol was catalyzed by the racemic, tethered compound, [Ru(η 6:η1-Me2NC6H4C 6H4PCy2-P)Cl2], generating (R)-1-(1-naphthyl)ethanol in 33% ee.; To evaluate the catalyst design, the effect of each transition metal catalyst's structure and chirality on product stereoselectivity was assessed. |
