SYNTHESIS OF ARYLACETYLENE AND VINYLACETYLENE DERIVATIVES BY COPPER-CATALYZED REACTION OF ARYL AND VINYL IODIDES WITH TERMINAL ALKYNES

The coupling reaction of aryl iodides with terminal alkynes by using a catalyst system of CuI-PPhs in the presence of K2CO3 as base gives th e corresponding arylated alkynes in excellent yields. Addition of PPh3 is essential for the reaction to proceed catalytically. Vinyl iodides also react smoothly with the alkynes to give enyne compounds with ret ention of the configurations. While DMF and DMSO can be used as solven ts, DMSO is found to be effective for the reaction with aliphatic term inal alkynes. A reaction mechanism involving initial formation of copp er acetylide species coordinated by PPh3 followed by reaction of aryl and vinyl iodides is proposed.