REDUCTION OF SOME POLYHALOGENATO- AND POLYACETOXY-ALLYLIC COMPOUNDS USING TRIBUTYLTIN HYDRIDE IN THE PRESENCE OR ABSENCE OF A PALLADIUM CATALYST. II.REDUCTION OF 1,1,1,4-TETRACHLOROBUT-2-ENE

Article abstract of DOI:10.1016/S0022-328X(00)99714-6

The radical tributyltin hydride reduction of 1,1,1,4-tetrachlorobur-2-ene yields a mixture of the expected 1,1,4-trichlorobut-2-ene and 1,1,4-trichlorobut-1-ene resulting from preferential abstraction of a chlorine atom from the trichloromethyl group.The palladium-catalyzed reduction follows an entirely different course, giving 1,1-dichlorobutadiene exclusively and quantitatively.The palladium-catalyzed reaction involves an oxidative addition-β-elimination process leading to dichlorobutadiene and a dichloropalladium(II) species.Tributyltin hydride reduction of palladium(II) to palladium(0) completes the catalytic cycle.