Metal-Catalyzed Asymmetric Hydrogenation of C═N Bonds

This Review recaps the achievements in the field of metal-catalyzed asymmetric direct hydrogenation of nonactivated and activated imines. A summary of the reported catalytic systems with the corresponding reactivity, selectivity, and limitations is given including a discussion about the effects of some reaction conditions on the enantioselectivity of imine hydrogenation. An analysis of proposed imine hydrogenation mechanisms is discussed.