Asymmetric hydrogenation of imines

The asymmetric hydrogenation of imines is a high atom economy method to prepare chiral amines. This review discusses the achievements made in the homogeneous metal-catalyzed asymmetric hydrogenation of imines, with particular emphasis on the last 10 years. Ir-catalysts have shown the highest activities and enantioselectivities, but over the years other metal-catalysts have been explored. We thus compile here the advances made with Ir-, Rh-, Ru- and Pd-catalysts, as well as with earth abundant metals, highlighting the scope and limitations of the detailed catalysts. This review also describes the application of these catalysts in the synthesis of complex molecules.