Gold-Catalyzed Cascade Cyclization and Amidation of 2-Alkynyl Arylazides To Access 3-Amidoindoles.

A gold-catalyzed cyclization and amidation of 2-alkynyl arylazides with nitriles and water is described. This protocol affords structurally diverse 3-amidoindoles in moderate to excellent yields under mild reaction conditions via the key benzene-fused α-imino gold carbene intermediate. Mechanistic studies reveal that the oxygen atom in the amide group is derived from water.