Selective diethylzinc reduction of imines in the presence of ketones catalyzed by Ni(acac)2

A selective reduction method of an electronically deficient imine in the presence of ketone was developed by employing Et(2)Zn and 5 mol % of Ni(acac)(2). The method was applied in the reduction of S(S)-tert-butanesulfinyl ketimines 1 to afford amines 2 in 23-92% yields and 73:27 to 98:2 diastereoselectivities. A plausible mechanism was proposed on the basis of an NMR study.