Palladium-Catalyzed Cyclization Reaction of o-Iodoanilines, CO2, and CO: Access to Isatoic Anhydrides

Abstract

Isatoic anhydrides, a class of valuable synthetic intermediates and RNA structure probing reagents, are usually prepared with highly toxic phosgene or stoichiometric oxidants. Herein we report a highly selective palladium-catalyzed cyclization reaction for the efficient synthesis of isatoic anhydrides from readily available o-iodoanilines, CO2, and CO. The reaction proceeds under mild conditions and is redox-neutral. Both CO2 and CO are indispensable C1 building blocks for this catalytic reaction.