Palladium-catalyzed hydroxycarbonylation of aryl and vinyl halides or triflates by acetic anhydride and formate anions.

[reaction: see text] The palladium-catalyzed reaction of aryl and vinyl halides or triflates in the presence of acetic anhydride and lithium formate as a condensed source of carbon monoxide provides an efficient simple route to the synthesis of the corresponding carboxylic acids. The reaction proceeds very smoothly under mild conditions and tolerates a wide range of functional groups, including ether, ketone, ester, and nitro groups. The presence of ortho substituents does not hamper the reaction. Labeled carbonyl products can be easily prepared by using H(13)COONa.