Silver/Indium-Catalyzed Cyclization of O -Alkynylisocyanobenzenes with Nitriles for the Synthesis of Amide-Substituted Quinolines

An efficient method for the synthesis of amide-substituted quinolines through silver/indium-catalyzed cyclization from o-alkynylisocyanobenzenes with nitriles has been reported. The reaction was initiated by the intramolecular cyclization of the o-alkynylisocyanobenzenes to generate the quinolyl cationic intermediate, followed by an intermolecular Ritter reaction with nitriles to give a nitrile-quinoline-based nitrilium salt, subsequently with hydrolysis to afford the amide-substituted quinolines.