Deprotection of Benzyl-Derived Groups via Uranyl-Photocatalysis

To circumvent the hazards associated with flammable/explosive hydrogen and address substrate compatibility issues in reductive systems, we developed a mild method for benzyl deprotection facilitated by uranium under visible light irradiation at ambient conditions. The uranium-oxo species, as a metal-oxo-type photosensitizer, demonstrates compatibility with moisture, enabling benzyl C–H activation through ligand-to-metal charge transfer (LMCT) excitation. Subsequent capture of the benzyl radical by atmospheric oxygen induces oxidation at the benzylic position. Removal of the semiacetal occurs, resulting in C–O bond cleavage under acidic conditions. This methodology, featuring mild conditions and operational convenience, is compatible with moisture and oxygen. It presents a complementary strategy for benzyl deprotection for the synthesis of pharmaceuticals and organic materials.