Enantioselective C( <i>sp</i> 3)–H amination of allyl benzene derivatives enabled by paddle-wheel diruthenium catalysis

Abstract Chemoselective allylic C(sp3)–H amination of alkenes is challenging in transition-metal-catalyzed nitrene insertion reactions due to the competitive formation of aziridines. In this report, we introduce chiral paddle-wheel diruthenium catalysts for achieving chemoselective C(sp3)–H amination of allyl benzene derivatives and summarize the reactivity trend of the diruthenium catalysts toward C(sp3)–H amination and aziridination of monosubstituted alkenes. Computational studies support that both C(sp3)–H amination and aziridination with paddle-wheel diruthenium catalysts proceed through radical intermediates. Chemoselectivity in the diruthenium-catalyzed C(sp3)–H amination of allyl benzene is likely controlled by the stabilities of the radical intermediate and α-vinyl benzylic radical and by noncovalent interactions between multiple phenyl rings in the ruthenium catalyst and substrates.