β-C(sp3)−H chlorination of amide derivatives via photoinduced copper charge transfer catalysis

An atom economic β-C(sp3)−H chlorination of amide derivatives has been developed. This mild protocol employs CuCl2 instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-stage functionalization of medicine derivatives. Mechanism studies suggest a plausible visible light triggered ligand-to-metal charge transfer (LMCT)/1,4-hydrogen atom transfer (HAT) cascade.