CATALYTIC ENANTIOSELECTION BY CHIRAL TRANSITION-METAL COMPLEXES. I. DEHYDROGENATION OF RACEMIC α-PHENYLETHANOL BY RuCl2(PPh3)3 AND (+)-NEOMENTHYLDIPHENYLPHOSPHINE

The enantioselective dehydrogenation of racemic (R-(+) and S-(−)) α-phenylethanol by RuCl2(PPh3)3 and (+)-neomenthyldiphenylphosphine at 180°C showed constant ratios of kR⁄kS in the absence of benzalacetone. The kR⁄kS value increased almost linearly with the benzalaceton concentration and decreased with the larger amounts of the chiral phosphine under the present reaction conditions.