Cu-Catalyzed Oxidative C(sp2)–H Cycloetherification of o-Arylphenols for the Preparation of Dibenzofurans

A new process involving copper-catalyzed aerobic C(sp2)–H activation, followed by cycloetherification, has been developed. This reaction serves as a direct method for the preparation of multisubstituted dibenzofurans starting with o-arylphenols. The presence of a strong para-electron-withdrawing group (e.g., NO2) on the phenol is essential for the success of the reaction.