Catalytic enantioselective protonation of cobalt–enolate equivalents generated by 1,4-reduction with borohydride

Abstract

In the presence of a catalytic amount of the optically active β-ketoiminato cobalt(II) complex and borohydride modified with appropriate alcohols, the 1,4-reduction of α-substituted-α,β-unsaturated carboxamides followed by in situ enantioselective protonation proceeded smoothly to afford optically active α-substituted carboxamides with good enantiomeric excess.