Copper-Catalyzed Regioselective C-H Aerobic Oxidative Cycloetherification of o-Arylphenols Bearing an Additional Directing Group

Abstract

An efficient copper-catalyzed C–H oxidative cycloetherification of <i>o</i>-arylphenols containing an additional directing group under an oxygen atmosphere was developed. 2,6-Disubstituted dibenzofuran derivatives were prepared by regioselective activation of the sterically more hindered C–H bond. The presence of the extra directing group not only controls the regioselectivity, but also increases the cyclization efficiency significantly.