Activation of Aryl Chlorides through π-Coordination for Radical Coupling with Arenes

Abstract π-Coordination of an aryl chloride to a chromium carbonyl fragment promotes radical coupling with an arene in the presence of potassium tert-butoxide as a base and a catalytic amount of a spirobipyridine derivative as a promoter. After removal of chromium under oxidative conditions, biaryl compounds are obtained in moderate to good yields. The chloroarene itself can be used as the substrate, after arene exchange with a chromium naphthalene complex to generate the chromium chloroarene complex in situ, followed by radical reaction with an arene.