The enantioselective hydrogenation of 2-alkyl-and 2-aryl-subsituted quinoxalines and 2, 3- disubstituted quinoxalines was developed by using the cationic Ru (η6-cymene)( monosulfonylated diamine)(BArF) system in high yields with up to 99% ee. The counteranion was found to be critically important for the high enantioselectivity and/or diastereoselectivity.