First example of asymmetric transfer hydrogenation in water induced by a chiral amino alcohol hydrochloride

The low-cost and commercially available (−)-ephedrine hydrochloride was firstly employed in the [RuCl2(p-cymene)]2-catalyzed asymmetric transfer hydrogenation of prochiral ketones in water. The reaction could be performed in the open air at rt, affording excellent yields (up to 99%) and good enantioselectivities (up to 83% ee). It provided a further step toward the discovery of simplified catalyst systems for eventual availability.