Gold-Catalyzed Direct Assembly of Aryl-Annulated Carbazoles from 2‑Alkynyl Arylazides and Alkynes

An unprecedented gold-catalyzed synthetic method for the direct assembly of aryl-annulated carbazoles from 2-alkynyl arylazides and alkynes is described. The reaction is proposed to proceed via a sequential cyclopropenation and intramolecular metal carbene/arene Friedel–Crafts-type reaction, respectively, mediated by two gold carbene intermediates.