The influence of several phosphineligands on the activity, selectivity and stability of the catalytic system Pd(acac)2, ligand, [HOEt2][BF4] was studied in the dimerization of methylacrylate (MA). It was found that the catalyst's activity increased with increasing the basicity of the monodentate ligands used, whereas bulky phosphines lowered the linearity of the dimers and the reaction rates. With