Visible-Light-Induced Aerobic ortho-Selective C–H Hydroxylation of Benzils

Abstract

Herein, we report a visible-light-induced ortho-selective C–H hydroxylation of benzils, which exhibits good functional group tolerance and excellent regioselectivity. This method is scalable, as demonstrated by gram-scale experiments, and is further applied in the synthesis of rotenoids. Control experiments reveal the involvement of singlet oxygen in the reaction mechanism. Moreover, it proceeds via a five-membered ring radical intermediate, with dimethyl sulfoxide serving both as the solvent and reducing agent.