CHEMISTRY OF DIAMINO-LIGATED METHYLPALLADIUM(II) ALKOXIDES AND ARYLOXIDES .2. METHOXIDE FORMATION AND CARBONYLATION REACTIONS

Reaction of N-ligated methylpalladium(II) alkoxide and aryloxide compl exes [Pd(Me)(OR)(N similar to N)] (R = Ph, CH(CF3)(2); N similar to N = tmeda (N,N,N',N'-tetramethylethylenediamine) or bpy (2,2'-bipyridyl) ) with carbon monoxide produces the corresponding methylesters in high yields. The insertion takes place either into the Pd-Me bond (aryloxi de complexes) or into the Pd-OR bond (alkoxide complexes). Methylpalla dium(II) methoxide complexes [Pd(Me)(OMe)(N similar to N)I (N similar to N = tmeda, bpy) have been generated in situ by aryloxide- or alkoxi de-methanol exchange reactions for which the equilibrium constants hav e been determined. The bpy-ligated methylpalladium methoxide complex u ndergoes insertion of CO producing either a methylpalladium methoxycar bonyl complex [Pd(Me)(CO(2)Me)(bpy)] (at -60 degrees C) or an acylpall adium methoxycarbonyl complex [Pd(COMe)(CO(2)Me)(bpy)] (at -25 degrees C); both carbonylated species could be isolated and characterized at low temperature.