Carboxylation of Benzylic and Aliphatic C-H Bonds with CO Induced by Light/Ketone/Nickel.

A photoinduced carboxylation reaction of benzylic and aliphatic C-H bonds with CO is developed. Toluene derivatives capture gaseous CO at the benzylic position to produce phenylacetic acid derivatives when irradiated with UV light in the presence of an aromatic ketone, a nickel complex, and potassium -butoxide. Cyclohexane reacts with CO to furnish cyclohexanecarboxylic acid under analogous reaction conditions. The present photoinduced carboxylation reaction provides a direct access from readily available hydrocarbons to the corresponding carboxylic acids with one carbon extension.