Palladium-catalyzed inter- and intramolecular coupling reactions of aryl and vinyl halides mediated by indium.

Treatment of aryl and vinyl halides with 50 mol % of 100 mesh indium, 2.5 mol % of Pd-C, and 1.5 equiv of LiCl under mild conditions (DMF, 100 degrees C, 1-3 h) could produce coupling products efficiently in good to excellent yields in which the C(sp2)-C(sp2) bond was formed. This reagent worked equally well with both intermolecular and intramolecular coupling reactions, producing a variety of biaryls, 1,3-dienes, and cyclic compounds.