Building up a conjugated system by the palladium-catalyzed arylation of ethylene (heck reaction)

The palladium-catalyzed arylation of ethylene under aqueous conditions has been studied. Both NaHCO₃-soluble and -insoluble bromo-and iodoarenes possessing electron-withdrawing groups react with ethylene to afford styrenes in good yields by water-soluble PdCl₂[tppms]₂ (tppms, m-(diphenylphosphino)benzenesulfonate). The Cr(CO)₃ complex of chlorobenzene reacts similarly under organic conditions. These reactions provide a synthetic route to poly(phenylenevinylenes).