Selective Late-Stage Oxygenation of Sulfides with Ground-State Oxygen by Uranyl Photocatalysis

Abstract

Oxygenation is a fundamental transformation in synthesis. Herein, we describe the selective late-stage oxygenation of sulfur-containing complex molecules with ground-state oxygen under ambient conditions. The high oxidation potential of the active uranyl cation (UO₂²⁺ ) enabled the efficient synthesis of sulfones. The ligand-to-metal charge transfer process (LMCT) from O 2p to U 5f within the O=U=O group, which generates a U^V center and an oxygen radical, is assumed to be affected by the solvent and additives, and can be tuned to promote selective sulfoxidation. This tunable strategy enabled the batch synthesis of 32 pharmaceuticals and analogues by late-stage oxygenation in an atom- and step-efficient manner.

Keywords: oxygen; oxygenation; photocatalysis; sulfides; uranyl catalysis.