COMBINED DECARBOXYLATION OF THE FORMATO LIGAND AND REDUCTIVE ELIMINATION OF HYDRIDO AND ARYL GROUPS IN THE SYNTHESIS OF RUTHENIUM(0) COMPLEXES. METHYLATION OF RUTHENIUM(0) WITH FORMALDEHYDE

Article abstract of DOI:10.1016/S0022-328X(00)85709-5

The formato ligand is readily introduced into the 5-coordinate complexes MRCl(CO)(PPh3)2 (M = Ru or Os, R = o-tolyl) giving 6-coordinate MR(η²-O2CH)(CO)(PPh3)2.In the presence of excess PPh3 thermal decarboxylation of the osmium complex leads to the stable aryl, hydride, OsRH(CO)(PPh3)3.A similar reaction with RuR(η²-O2CH)(CO)(PPh3)2 is accompanied by reductive elimination of RH and formation of Ru(CO)(PPh3)3 which as a solid is ortho-metallated, i.e. exists as .Decarboxylation and reductive elimination in the presence of bis(diphenylphosphino)ethane (dppe) give the zerovalent Ru(CO)(dppe)2. Ru(CO)(PPh3)3 undergoes a most unusual reaction with formaldehyde forming Ru(CH3)(η²-O2CH)(CO)(PPh3)2.