Josiphos-type binaphane ligands for the asymmetric Ir-catalyzed hydrogenation of acyclic aromatic N-aryl imines

Abstract

The Ir-catalyzed asymmetric hydrogenation of acyclic aromatic N-aryl imines with Josiphos-type binaphane ligands has been described. Under the optimized conditions, a wide range of imines were hydrogenated to afford the corresponding chiral amines in high yields (up to 94%) and good to excellent enantioselectivities (up to >99% ee). The synthetic utility of the present protocol has been demonstrated through the asymmetric synthesis of the key chiral intermediates of calcium sensing receptor modulators on a gram scale.