Stereogenic -2-substituted--acetyl-3-hydroxy-indolines ruthenium()-catalyzed dynamic kinetic resolution-asymmetric transfer hydrogenation

Ruthenium( ii )-catalyzed dynamic kinetic resolution-asymmetric transfer hydrogenation of racemic 2-substituted- N -acetyl-3-oxoindolines to cis -2-substituted- N -acetyl-3-hydroxyindolines is reported. Using the homochiral {Ru[TfDPEN]( p -cymene)} catalyst with S/C = 400 in a HCO 2 H/Et 3 N mixture, up to >99.9% ee and >99 : 1 dr are obtained with high yields (79-98%). This method provides the first example of preparing enantiomerically pure indolines through asymmetric transfer hydrogenation (ATH). Ruthenium( ii )-catalyzed dynamic kinetic resolution-asymmetric transfer hydrogenation of racemic 2-substituted- N -acetyl-3-oxoindolines is reported, affording cis -2-substituted- N -acetyl-3-hydroxyindolines in high yields with excellent diastereoselectivity and enantioselectivity.