Regioselective C-H sulfenylation of N -sulfonyl protected 7-azaindoles promoted by TBAI: a rapid synthesis of 3-thio-7-azaindoles.

This paper describes the regioselective C-3 sulfenylation of N -sulfonyl protected 7-azaindoles with sulfonyl chlorides. In this transformation, dual roles of TBAI serving as both promoter and desulfonylation reagent have been demonstrated. The reaction proceeded smoothly under simple conditions to afford 3-thio-7-azaindoles in moderate to good yields with broad substrate scopes. This protocol refrains from using transition-metal catalysts, strong oxidants or bases, and shows its practical synthetic value in organic synthesis.
Competing Interests: There are no conflicts to declare.
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