Rhodium-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Carbonyl Compounds via Thiourea Hydrogen Bonding

The strategy of secondary interaction enables enantioselectivity for homogeneous hydrogenation. By in, troducing hydrogen bonding of substrates with thiourea from the ligand, alpha,beta-unsaturated carbonyl, compounds, such as amides and esters, are hydrogenated with high enantiomeric excess. The substrate scope for this chemical transformation is broad with various substituents at the beta-position. Control experiments revealed that each unit of the ligand ZhaoPhos is irreplaceable. No nonlinear effect was observed for this Rh/ZhaoPhos-catalyzed asymmetric hydrogenation.