RU(CO)4(PME2PH) CATALYZED CARBONYLATION OF RU(CH3)I(CO)2(IPR-DAB) AND RU(CH3)I(CO)2(IPR-PYCA) COMPLEXES - X-RAY STRUCTURE OF [RU(CH3)(CO)2[(2-METHOXYETHYL)PYCA]][OTF]

The synthesis and characterization of complexes Ru(R)X(CO)2(R'-Pyca) (R = CH3 and X = 1 (2); R = C(O)CH3 and X = I (3); R = CH3 and X = OTf = SO3CF3 (4); R = C(O)CH3 and X = OTf (5); R1-Pyca = 2-R1-pyridinecarbaldimine; and R' = isopropyl (b), methoxyethyl (c), or isopropoxypropyl (d)), respectively, will be presented. The X-ray structure determination of the yellow crystals of [Ru(CH3)(CO)2(CH3OCH2CH2-Pyca)][OTf] (4c) has been carried out. Crystal data for 4c. monoclinic, space group P2(1)/c with a = 8.5008(4) angstrom, b = 12.3281(8) angstrom, c = 18.412(1) angstrom, beta = 01.118(6)-degrees, V = 1893.4(2) angstrom3, z = 4. The Ru(CO)4(PMe2Ph) (13) catalyzed CO insertion in the methyl-ruthenium bond of Ru(CH3)X(CO)2(iPr-DAB) (X = I (2a); X = OTf (4a); X = Cl (6a); DAB = 1,4-diaza-1,3-butadiene) and Ru(CH3)X(CO)2(iPr-Pyca) (X = I (2b); X = OTf (4b)) has been studied by use of labeled Ru((CO)-C-13)4(PMe2Ph) (13) and by reaction in the absence or presence of additional ligand PPh3 and CO. For the neutral complexes 2a, 6a, and 2b the key intermediate for the CO insertion catalyzed by 13 is most probably of the type [Ru(CH3)X(CO)(alpha-diimine)Ru(CO)3(PMe2Ph)(mu-CO)2] (X1), which is, however, not observed during the reaction. By (CO)-C-13 labeling experiments it has clearly been demonstrated that binuclear species are involved in this reaction. Complex Ru(CO)4(PMe2Ph) (13) decomposes in CDCl3 at 45-degrees-C under N2 and under a CO atmosphere (1 and 8 atm) within 3 h to form Ru2(CO)4(PMe2Ph)2(mu-Cl)2 (15), which can further react with PPh3 to Ru2(CO)4(PMe2Ph)2(PPhs)2(mu-Cl)2 (16). Suprisingly, 13 is stable under high CO pressure in the presence of 2a, 6a, and 2b in CDCl3 at 45-degrees-C for several hours, most probably as a result of a faster reaction of Ru(CO)4(PMe2Ph) (13) or most likely [Ru(CO)3(PMe2Ph)] with 2a, 6a, or 2b than with CDCl3, which prohibits decomposition.