Nickel-Catalyzed Electrochemical Cyclization of Alkynyl Aryl Iodide and the Domino Reaction with Aldehydes.

An intramolecular carbometallation of a triple bond promoted by electrochemistry and mediated by nickel catalysis is described. This domino process transforms various aryl halides bearing a propargyl chain into substituted heterocycles in one single operation, with high stereoselectivities and in good to high yields. This reaction, characterized by a cyclic voltammetry set of experiments, proceeds following a syn-exo-dig cyclization process. When run at 80 °C, vinylbenzofuranes that are suitable substrates for cycloaddition reactions are obtained.