The Reaction Pattern of the MoCl5-Mediated Oxidative Aryl-aryl Coupling

The oxidative coupling of electron rich aryls by molybdenum pentachloride is reported. The stoichiometry of the coupling reaction reveals that MoCl 5 is a single electron acceptor. Interestingly, the 1,2-dialkoxy substitution pattern is pivotal for the aryl-aryl coupling.