PALLADIUM-CATALYZED CROSS-CARBONYLATION OF ARYL IODIDES WITH 5-MEMBERED CYCLIC OLEFINS

Intermolecular cross-carbonylation of aryl iodides with five-membered cyclic olefins such as dihydrofurans and cyclopentene was found to pro ceed by using a catalyst system of PdCl2/PPh(3) under CO (3-5 atm) in the presence of a tertiary amine. With 2,3- and 2,5-dihydrofurans, 2-a royl-4,5-dihydro- and 3-aroyl-2,3-dihydrofurans were obtained as the p redominant products, respectively, while the reaction of iodobenzene w ith cyclopentene gave a mixture of three regioisomers of benzoylcyclop entene. The yields of the products were observed to be markedly influe nced by the amount of triphenylphosphine added.