Nickel-Photocatalytic Decarboxylative Oxidation of Mandelic Acids

Selective oxidation of α-hydroxy acids, particularly Mandelic acids, was achieved by merging Nickel and photoredox catalysis. This approach enables the discrete formation of aldehydes and ketones without observable overoxidation. By decoupling the decarboxylation and alcohol oxidation/dehydrogenation steps, the reaction proceeds under free-radical conditions to afford prod- ucts in high-yield. The method described is scalable and holds the potential for broadening the scope of metallaphotoredox catalysis in coupled oxidation processes.