Decarbonylative Alkynylation of Aryl Anhydrides via Palladium Catalysis.

A robust palladium-catalyzed decarbonylative alkynylation of aryl anhydrides is reported. The catalytic system of Pd(OAc)/XantPhos and DMAP as a nucleophilic additive has been identified as effective promoters for decarbonylative Sonogashira alkynylation. Recently, activated esters, amides, and carboxylic acids were applied as electrophiles in transition-metal-catalyzed decarbonylative alkynylation. The present process expands this reactivity to readily available aryl anhydrides as electrophilic reagents for decarbonylative alkynylation. It is worth noting that the reactivity of aryl anhydrides is higher than that of esters, amides, and carboxylic acids in decarbonylative alkynylation. Broad substrate scope and excellent functional group tolerance are presented, demonstrating that aryl anhydrides may serve as a general and practical class of electrophiles to achieve the synthesis of internal alkynes.