Asymmetric Hydrogenation of α-Alkyl-Substituted β-Keto Esters and Amides through Dynamic Kinetic Resolution.

Asymmetric hydrogenation of α-alkyl-substituted β-keto esters and amides with the DIPSkewphos/3-AMIQ-Ru(II) catalyst system through dynamic kinetic resolution was examined. A series of β-keto esters and amides with a simple or functionalized α-alkyl group were applicable to this reaction, affording the α-substituted β-hydroxy esters and amides in ≥99% ee ( anti / syn ≥ 99:1) in many cases. The 5 g scale reaction was readily achieved. The mode of enantio- and diastereoselection in the transition state model was proposed.