Developing chiral ligands for asymmetric hydrogenation.

This Account outlines our efforts in ligand development for asymmetric hydrogenation. The successful development of three classes of ligands is presented, including (1) ligands with phosphocyclic motifs, (2) ligands with atropisomeric backbones, and (3) bisphosphine ligands inspired by the structure of 2,3- O-isopropylidene-2,3-dihydroxyl-1,4-bis(diphenylphosphino)butane (DIOP). With this large ligand toolbox, we have prepared many pharmaceutically valuable chiral products efficiently.