Novel and Efficient Chiral Bisphosphorus Ligands for Rhodium-Catalyzed Asymmetric Hydrogenation

A series of structurally novel, operationally convenient, and efficient chiral 2-phosphino-2,3-dihydrobenzo[d][1,3]oxaphosphole ligands was developed. Applications of ligands 3a and 3b in rhodium-catalyzed asymmetric hydrogenation of alpha-(acylamino)acrylates and beta-(acylamino)acrylates provided excellent enantioselectivities (up to >99% ee) and reactivities (up to 10 000 TON).