Direct Phosphatation via Arylthianthrenium Salts

O-Phosphorylation is a common way to make phosphates, but its reliance on the formation of an O-P bond restricts it to hydroxyl groups and lacks selectivity with other competing nucleophiles. Herein, we report a photoredox/copper-mediated method to construct phosphates via C-O bond formation. This approach uses arylthianthrenium salts to generate aryl radicals, which can be captured by high-valent copper species to form the challenging C-O bond with dialkyl phosphates. The reaction exhibits a broad substrate scope, enables late-stage functionalization of drug molecules, and operates orthogonally with conventional O-phosphorylation. This allows for the direct phosphatation of complex molecules bearing problematic functionality without resorting to complicated protection group schemes.