Development of DIOP derivatives as efficient ligands for asymmetric hydrogenation: factors controlling the reactivities and enantioselectivities

Several DIOP derivatives have been developed as efficient ligands for Rh and Ir-catalyzed asymmetric hydrogenations. The conformational mobility of the backbone in this type of ligand plays an important role in governing both the reactivity and enantioselectivity. Isolation of pure pre-catalyst is another key factor to obtain high catalytic activity. (C) 2004 Published by Elsevier Ltd.