Photoredox aerobic oxidation of unreactive amine derivatives through LMCT excitation of copper dichloride

Abstract

This work demonstrates a versatile oxidation system, a combination of CuCl₂ and visible light, which is applicable to both C–H oxidation and N-demethylation and works for diverse categories of inert amine derivatives, including secondary and tertiary amides, sulfonamides, carbamates, and α-ketoamides. In addition, this ligand-to-metal charge transfer process uses molecular oxygen as a terminal oxidant and has a low cost catalytic system, broad functional group compatibility, easy availability of starting materials, and extraordinarily mild conditions. A preliminary mechanistic investigation indicates that the facile formation of a chlorine radical and the subsequent radical cascade reaction are involved in this photoredox process.