The Codimerization of Styrene with Ethylene Catalyzed by Olefin-palladium(II) Chloride Complexes

Publisher Website
Google Scholar
Abstract
The codimerization of styrene with ethylene catalyzed by the olefin-palladium chloride complexes was investigated in a homogeneous system under mild conditions; di-μ-chloro-dichlorobis-(styrene)dipalladium(II), (Pd(C6H5CH=CH2)Cl2)2, was found to be an effective catalyst. When ethylene was bubbled into a styrene solution containing the styrene-palladium complex at 50°C for 6 hr, codimers including trans-1-phenyl-1-butene, cis-1-phenyl-1-butene, and trans-1-phenyl-2-butene were obtained in 1278, 57 and 170% yields respectively, based on palladium(II) used. However, the absence of ethylene resulted in the formation of a 70% yield of the dimer of styrene, trans-1,3-diphenyl-1-butene. The order of the solvent effect on the rate of the codimerization was as follows: nitrobenzene>nitromethane>acetic acid, phenol>dioxane>>benzene>>acetonitrile. A possible mechanism for this reaction was discussed on the basis of the present results.