Enantioselective borohydride 1,4-reduction of α,β-unsaturated carboxamides using optically active cobalt(II) complex catalysts

The enantioselective borohydride reduction catalyzed by cobalt(II) complex was successfully applied to 1,4-reduction of β,β-disubstituted α,β-unsaturated carboxamides. In the presence of less than 1 mol% of optically active aldiminato cobalt(II) complex catalyst, the corresponding carboxamides were obtained in high yields with high enantiomeric excesses.