Activation of two C-H bonds of NHC N-methyl groups on triosmium and triruthenium carbonyl clusters.
The thermolysis of the NHC triosmium cluster [Os3(Me2Im)(CO)11] (1a; Me2Im = 1,3-dimethylimidazol-2-ylidene) in toluene at reflux temperature sequentially affords the edge-bridged cluster [Os3(micro-H)(micro-kappa2-MeImCH2)(CO)10] () and the face-capped derivative [Os3(micro-H)2(micro3-kappa2-MeImCH)(CO)9] (3a). These products result from the sequential oxidative addition of one (2a) and two (3a) N-methyl C-H bonds of the original NHC ligand. The related face-capped triruthenium cluster [Ru3(micro-H)2(micro3-kappa2-MeImCH)(CO)9] (3b) has been prepared by heating the NHC triruthenium cluster [Ru3(Me2Im)(CO)11] (1b) in THF at reflux temperature. In this case, the pentanuclear derivatives [Ru5(Me2Im)(micro4-kappa2-CO)(CO)14] (4b) and [Ru5(Me2Im)2(micro4-kappa2-CO)(CO)13] (5b) are minor reaction products, but a ruthenium cluster analogous to has not been obtained. The face-capped oxazole-derived NHC triruthenium cluster [Ru3(micro-H)2(micro3-kappa2-OxCH)(CO)9] (3c; MeOx = N-methyloxazol-2-ylidene) is the only isolated product of the thermolysis of [Ru3(MeOx)(CO)11] (1c) in THF at reflux temperature.
Cabeza
Javier A
JA
Departamento de Química Orgánica e Inorgánica, Instituto de Química Organometálica Enrique Moles, Universidad de Oviedo-CSIC, E-33071, Oviedo, Spain. jac@fq.uniovi.es
Del Río
Ignacio
I
Miguel
Daniel
D
Pérez-Carreño
Enrique
E
Sánchez-Vega
M Gabriela
MG
D002248:Carbon Monoxide / Q000737:chemistry; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D009992:Osmium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013696:Temperature
D007093:Imidazoles; D008024:Ligands; D009942:Organometallic Compounds; D009992:Osmium; D002248:Carbon Monoxide; D012428:Ruthenium