Ruthenium-catalyzed asymmetric transfer hydrogenation of ketones in ethanol

A ruthenium catalyst formed in situ by combining [Ru(p-cymene)Cl2]2 and an amino acid hydroxy-amide was found to catalyze efficiently the asymmetric reduction of aryl alkyl ketones under transfer hydrogenation conditions using ethanol as the hydrogen donor. The secondary alcohol products were obtained in moderate to good yields and with good to excellent enantioselectivity (up to 97% ee).