Selective Oxidative Homo- and Cross-Coupling of Phenols with Aerobic Catalysts

Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho–ortho, ortho–para, or para–para homo-couplings of phenols are described. In addition, chromium salen catalysts have been discovered as uniquely effective in the cross-coupling of different phenols with high chemo- and regioselectivity.