Photocatalytic Carbon–Carbon σ‑Bond Anaerobic Oxidation of Ketones with Water by Rhodium(III) Porphyrins

Photocatalytic carbon–carbon σ-bond oxidation of unstrained ketones by water using rhodium­(III) porphyrin catalyst was accomplished. The catalysis yielded the corresponding one-carbon-less carbonyl compound and H₂ with up to 30 turnovers in both aliphatic and cyclic ketones with α substituents. No carbon loss was observed in aromatic ketone. Mechanistic studies suggest that (Ph₃P)­Rh^III(ttp)­OH (ttp = tetratolylporphyrinato dianion) is the key intermediate in the carbon–carbon σ-bond anaerobic oxidation