Carboxylation of benzyl halides has been reported. The reaction mechanism is proposed to involve oxidative addition of benzyl chloride to Ni(0). The Ni(II) benzyl complex is reduced to Ni(I), e.g., by zinc, which inserts CO delivering the nickel carboxylate. Reduction of the Ni(I) carboxylate to Ni(0) releases the zinc carboxylate (Scheme 6). Similarly, such carboxylation has been achieved on aryl and benzyl pivalate, alkyl halides, and allyl esters.