Ir/BiphPHOX-catalyzed asymmetric hydrogenation of 3-substituted 2,5-dihydropyrroles and 2,5-dihydrothiophene 1,1-dioxides

Abstract

An efficient asymmetric hydrogenation of 3-substituted 2,5-dihydropyrroles using an Ir catalyst with an axially flexible chiral phosphine-oxazoline ligand was developed and chiral 3-substituted pyrrolidines could be prepared with excellent ee. 3-Substituted 2,5-dihydrothiophene 1,1-dioxides could also be hydrogenated by our catalyst, giving the desired products with moderate to high enantioselectivities.