Cu-Catalyzed Direct C7 Sulfonylation of Indolines with Arylsulfonyl Chlorides.

An efficient Cu-catalyzed direct sulfonylation of indolines with easily accessible sulfonyl chlorides has been realized under an air atmosphere via a chelation-assisted strategy. This protocol exhibits several unique characteristics, including broad substrate scope, good functional group tolerance, and operational convenience, which enable a regioselective access to a variety of C-7 functionalized indoline scaffolds in moderate to good yields. The mechanistic study reveals that the sulfonyl radical might be involved in this transformation.