Enantioselective Intermolecular Benzylic C–H Amination under Chiral Paddle-Wheel Diruthenium Catalysis

A catalytic asymmetric intermolecular benzylic C–H amination was achieved under paddle-wheel diruthenium catalysis. A chiral diruthenium catalyst incorporating (S)-TPPTTL (tetraphenylphthaloyl-(S)-tert-leucine) ligand exhibited notable enantioselectivity, and aminated products were obtained with up to 99% ee. Unique chemoselectivity of the chiral diruthenium catalyst was also found for allylbenzene and alkyl-naphthalene substrates, demonstrating the complementary synthetic utility of chiral paddle-wheel Ru(II)–Ru(III) catalysts to Rh(II) counterparts.