RU(CO)4(PME2PH) CATALYZED CARBONYLATION OF RU(CH3)I(CO)2(IPR-DAB) ANDRU(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-pyridinecarb aldimine; and R' = isopropyl (b), methoxyethyl (c), or isopropoxypropy l (d)), respectively, will be presented. The X-ray structure determina tion of the yellow crystals of [Ru(CH3)(CO)2(CH3OCH2CH2-Pyca)][OTf] (4 c) 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 = 18.4 12(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-ruth enium 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 addition al ligand PPh3 and CO. For the neutral complexes 2a, 6a, and 2b the ke y intermediate for the CO insertion catalyzed by 13 is most probably o f the type u(CH3)X(CO)(alpha-diimine)Ru(CO)3(PMe2Ph)(mu-CO)2] (X1), wh ich is, however, not observed during the reaction. By (CO)-C-13 labeli ng experiments it has clearly been demonstrated that binuclear species are involved in this reaction. Complex Ru(CO)4(PMe2Ph) (13) decompose s 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 fur ther react with PPh3 to Ru2(CO)4(PMe2Ph)2(PPhs)2(mu-Cl)2 (16). Suprisi ngly, 13 is stable under high CO pressure in the presence of 2a, 6a, a nd 2b in CDCl3 at 45-degrees-C for several hours, most probably as a r esult 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 deco mposition.