Highly Enantioselective Asymmetric Hydrogenation of Carboxy-Directed alpha,alpha-Disubstituted Terminal Olefins via the Ion Pair Noncovalent Interaction

The t-Bu-Wudaphos was successfully applied into Rh-catalyzed asymmetric hydrogenation of alpha,alpha-disubstituted terminal olefins bearing a carboxy-directed group with excellent reactivities and enantioselectivities via the ion pair noncovalent interaction (up to >99% conversion, 98% yield, 98% ee) under mild reaction conditions without base. In addition, control experiments were conducted, and the results demonstrated that the ion pair noncovalent interaction between ligand and substrate played an important role in achieving an outstanding performance in this asymmetric hydrogenation.