Rh/Wudaphos-Catalyzed Asymmetric Hydrogenation of Sodium alpha-Arylethenylsulfonates: A Method To Access Chiral alpha-Arylethylsulfonic Acids

A highly enantioselective hydrogenation of various sodium alpha-arylethenylsulfonates catalyzed by Rh/chiral ferrocenyl bisphosphorus ligand (Wudaphos) was successfully developed to construct a series of chiral alpha-arylethylsulfonic acids in the presence of CF3SO3H with full conversion and good to excellent enantioselectivity (>99% conversion, up to 96% ee) under mild reaction conditions for the first time. Moreover, the control experiment results showed that the non covalent ion pair interaction between the alpha-arylethenylsulfonic acid and the Wudaphos ligand plays an important role in this asymmetric hydrogenation system.