Alkenes dichlorobis palladium

Solvent effects on, and products from, reaction of styrene with ethylene in the presence of di-)ti-chloro-dichlorobis(styrene)dipalladium(n), [Pd-(Ph CH—CH2)Cl2]2, indicate a mechanism similar to (i)->(iv) above, with the addition of a preliminary equilibrium between the dimer and solvated monomers. The mechanism of reaction of styrene with vinyl compounds, catalysed by the same chloride-bridged dipalladium complex, has been studied using isotopic tracer (H, D) experiments. Palladium-acetate-catalysed reaction of styrene with benzene, also investigated using deuterium tracer experiments, involves no hydride shift, in contrast to the rather closely related Wacker process. The importance of intermediates with palladium-carbon n-bonds in palladium(ii)-catalysed alkylation and arylation of alkenes has been demonstrated. 

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