Ru–Prolinamide-Catalyzed Asymmetric Transfer Hydrogenation of Racemic β-Heterosubstituted Cycloalkanones Driven by Dynamic Kinetic Resolution

A ruthenium–prolinamide catalytic system has been applied for the first time in dynamic kinetic resolution/asymmetric transfer hydrogenation reactions (DKR/ATH) in aqueous medium to synthesize cis-β-heterosubstituted cycloalkanols with two contiguous chiral centers. The effect of various prolinamide ligands in DKR/ATH has been studied on different racemic-β-heterosubstituted cycloalkanones. A prolinamide ligand with a bulky substituent at an ortho position proves to be more effective than the previously reported ruthenium–TsDPEN catalytic system in aqueous medium, producing up to 99.1 % enantioselectivity and 99:1 diastereoselectivity.