Copper‐Catalyzed Aerobic Benzylic C(sp³)−H Oxidation of Unprotected Aniline Derivatives for the Synthesis of Phenanthridines

Herein, we report a copper‐catalyzed intramolecular benzylic C( sp 3 )−H oxidation of unprotected aniline derivatives under aerobic conditions, which enables the preparation of phenanthridine compounds. To the best of our knowledge, this is the pioneering reaction of dehydrogenative C( sp 3 )−N bond formation from unprotected anilines under a Cu/O 2 system. Notably, various anilines possessing alkyl, methoxy, halogen (fluoride, chloride, bromide, and iodide), trifluoromethyl, trifluoromethoxy, cyano, ester, and acetal groups can also participate in the reaction.