Recyclable selective palladium-catalyzed synthesis of five-, six- or seven-membered ring lactones and lactams by cyclocarbonylation in ionic liquids

The ionic liquids, BMIM PF6 or BMIM NTf2, are used successfully for the palladium-catalyzed cyclocarbonylation of 2-allylphenols and anilines, 2-vinylphenols, and 2-aminostyrenes. The reaction proceeds cleanly and efficiently to afford high yields of lactones or lactams with good or excellent selectivity for one isomer. The ionic liquid containing the palladium catalyst, and ligand, is recyclable in all cases.