Progress on the Catalytic Asymmetric Hydrogenation of Imines

Abstract

Chiral amines are important synthetic intermediates in the preparation of many physiologically active compounds. Catalytic asymmetric hydrogenation of prochiral imines represents one of the most direct and convenient route to chiral amines and their derivatives. During the past two decades, significant progress has been made in the asymmetric hydrogenation of imines. Many highly enantioselective chiral catalysts have been disclosed, some new methods and strategies have been developed, and some challenging imines substrates have been efficiently hydrogenated in high enantioselectivities. Despite these achievements, catalytic asymmetric hydrogenation of imines still have challenges of low reactivity, narrow substrate scope, harsh hydrogenation conditions and difficulty in catalyst reuse. Therefore, development of new catalyst system with high reactivity and enantioselectivity as well as environmental friendship in the asymmetric hydrogenation of imines is of great interest. This review presents a brief overview on the progress in catalytic asymmetric hydrogenation of cyclic and acyclic imines.