CuI-Catalyzed intramolecular aminocyanation of terminal alkynes in N-(2-ethynylphenyl)-N-sulfonylcyanamides via Cu–vinylidene intermediates

Abstract

CuI-Catalyzed intramolecular aminocyanation of terminal alkynes in N-(2-ethynylphenyl)-N-sulfonylcyanamides was initiated by the formation of Cu–acetylide to trigger N–CN bond cleavage of the N-sulfonylcyanamide moiety followed by CN migration to form a β-cyano Cu–vinylidene intermediate. Subsequently, the indole ring closure furnished the corresponding 1-sulfonyl-3-cyanoindoles.