Cu‐Catalyzed Intramolecular Amidation of Unactivated C(sp 3 )−H Bonds To Synthesize N‐Substituted Indolines

A copper‐catalyzed intramolecular amidation of unactivated C(sp 3 )−H bonds to construct indoline derivatives has been developed. Such an amidation proceeded well at primary C−H bonds preferred to secondary C−H bonds. The transformation owned a broad substrate scope. The corresponding indolines were obtained in good to excellent yields. N ‐Formal and other carbonyl groups were suitable and were easily deprotected and transformed into methyl or long‐chained alkyl groups. Preliminary mechanistic studies suggested a radical pathway.