Modification of chiral monodentate phosphine (MOP) ligands for palladium-catalyzed asymmetric hydrosilylation of styrenes

In the palladium-catalyzed asymmetric hydrosilylation of styrene with trich lorosilane, several chiral monophosphine ligands, (R)-2-diarylphosphino-1,1 '-binaphthyls (2), were examined for their enantioselectivity. The highest enantioselectivity was observed in the reaction with (R)-2-bis[3,5-bis(trif luoromethyl)phenyl]phosphino- 1,1'-binaphthyl (2g), which gave (S)-1-phenyl ethanol of 98% ee after oxidation of the hydrosilylation product.