Chemistry of diamino-ligated methylpalladium(II) alkoxides and aryloxides (Part II): Methoxide formation and carbonylation reactions

Article abstract of DOI:10.1016/0022-328X(96)06171-2

Reaction of N-ligated methylpalladium(II) alkoxide and aryloxide complexes [Pd(Me)(OR)(N ～ N)] (R = Ph, CH(CF₃)₂; N ～ 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 (aryloxide complexes) or into the Pd-OR bond (alkoxide complexes). Methylpalladium(II) methoxide complexes [Pd(Me)(OMe)(N ～ N)] (N ～ N = tmeda, bpy) have been generated in situ by aryloxide- or alkoxide-methanol exchange reactions for which the equilibrium constants have been determined. The bpy-ligated methylpalladium methoxide complex undergoes insertion of CO producing either a methylpalladium methoxycarbonyl complex [Pd(Me)(CO₂Me)(bpy)] (at -60°C) or an acylpalladium methoxycarbonyl complex [Pd(COMe)(CO₂Me)(bpy)] (at -25°C); both carbonylated species could be isolated and characterized at low temperature.