THE MECHANISM OF REACTIONS OF ORGANOPALLADIUM SALTS WITH VINYLCYCLOPROPANES

Article abstract of DOI:10.1016/0022-328X(85)80308-9

Cyclopropylmercuric chloride, lithium chloropalladite and methyl acrylate react at 0-25 deg C to give an 81percent yield of methyl sorbate.A ?-allylic palladium intermediate is proposed since vinylcyclopropane, carbomethoxymercuric acetate, and lithium chloropalladate give the same product.The corresponding reactions with styrene and cyclopropylmercuric chloride or vinylcyclopropane and phenylmercuric chloride also give the same, isolable ?-allylic palladium complex.Deuterium labeling experiments support the occurrence of a common intermediate in the two reactions. 1,1-Dicarboethoxy-2-vinylcyclopropane reacts similarly with "phenylpalladium chloride" but the ?-allylic product has the palladium attached at the benzyl carbon rather than the next carbon away.The reaction with "phenylpalladium acetate" in place of the chloride yields only dienes.Studies with the deuterated vinylcyclopropane diester suggest that the mode of elimination from the initial palladium adduct is strongly influenced by the anion present.The reaction of "cyclopropylpalladium chloride" with alkenes appears to be a general method for preparing, selectively, internal ?-allylic palladium complexes.