Intramolecular dehydrogenative amination of alkenes via dual organic photoredox and cobalt catalysis without a hydrogen acceptor

Abstract

Direct C–H/N–H dehydrogenative coupling is a promising yet thermodynamically unfavorable transformation in the absence of a sacrificial hydrogen acceptor. Herein, a conceptually novel oxidant-free dehydrogenative amination of alkenes through a synergistic photoredox and cobalt catalysis with H₂ evolution has been achieved. With this approach, a wide range of five-membered N-heterocycles were synthesized with excellent atom-economy. The green system will address the challenges that are sensitive to traditionally oxidative conditions. Furthermore, the scope and mechanistic details of the method are discussed.