CATALYTIC TAIL-TO-TAIL DIMERIZATION OF METHYL ACRYLATE USING BIS(TRIPHENYLPHOSPHINE)TRICARBONYL RUTHENIUM(0)

The complex RU(CO)(3)(PPh3)(2) catalyzes the dimerization of methyl ac rylate at 120-140 degrees C to give tail-to-tail dimers containing pre dominantly dimethyl (E)-2-hexene-1,6-dioate together with small amount s of trimers and polymer. The reaction under hydrogen atmosphere selec tively gave tail-to-tail dimers in improved yield without formation of trimers and polymer. Under these conditions a catalyst turnover numbe r of 246 was obtained at 130 degrees C in 6 h.