New catalyst precursors constituted of AsPh3 and palladium on carbon or palladium(III) acetate as efficient promoters of selective cross-coupling reactions between functionalized alkenyl halides and aryl- or 1-alkynylzinc chlorides

The catalyst precursor consisting of a mixt. of 10% palladium on carbon and 3.9 equiv. of AsPh3 as well as that obtained by treatment of Pd(OAc)2 with 4 equiv of AsPh3 in THF at 60° for 1 h have proven to be suitable for promoting efficient cross-coupling reaction between aryl- or 1-alkynylzinc chlorides and alkenyl halides which contain an electron-withdrawing substituent linked to their carbon-carbon double bond. The activity of these catalyst precursors has been found to be comparable to that of the more expensive and air unstable Pd(PPh3)4