Transition Metal‐Free One‐Pot Approach: Regioselective Synthesis of Pyrrolo[3,4‐b]quinolin‐1‐one Derivatives from o‐Alkynylquinoline‐3‐carbonitriles

A KOtBu‐promoted robust strategy has been described for the regioselective synthesis of pyrrolo[3,4‐b]quinolin‐1‐one and naphthyridin‐1(2H)‐one derivatives from o‐alkynylquinolinecarbonitriles in good to excellent yields. The reaction proceeds through in‐situ transformation of nitrile moiety into amide group followed by the selective C‐N bond formation via a 5‐exo‐dig or 6‐endo‐dig annulation reaction. Among the synthesized derivatives, 6‐endo‐dig naphthyridin‐1(2H)‐ones displayed good photophysical properties. The present approach is superior to other established methodologies owing to avoiding use of transition metals and column chromatographic purification and affording the products in high yields. Additionally, the current methodology provides several additional advantages like one‐pot operation, high atom economy, broad substrate scope and step‐economical process.