Nickel‐Photocatalytic Decarboxylative Oxidation

Selective oxidation of α ‐hydroxy acids, particularly mandelic acids, is 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 steps, the reaction proceeds under free‐radical conditions with high efficiency. Mechanistic studies underscore the role of the nickel catalyst in facilitating these transformations. Additionally, this approach is extended to the decarboxylative oxidation of β ‐hydroxy acids and phenylglycines, generating carbonyl compounds upon hydrolysis. This method is scalable and holds the potential for broadening the scope of nickel‐photoredox catalysis in oxidative processes.