Bolaño, Tamara, Esteruelas, Miguel A., Gay, M. Pilar, Oñate, Enrique, Pastor, Isidro M., Yus, Miguel
An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B–H and O–H Bond Activation
Organometallics. 2015, 34(15): 3902–3908. doi:10.1021/acs.organomet.5b00418
URI: http://hdl.handle.net/10045/50286
DOI: 10.1021/acs.organomet.5b00418
ISSN: 0276-7333 (Print)
Abstract: 
The hexahydride complex OsH6(PiPr3)2 (1) activates the C–OMe bond of 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium chloride (2), in addition to promoting the direct metalation of the imidazolium group, to afford a five-coordinate OsCl(acyl-NHC)(PiPr3)2 (3) compound. The latter coordinates carbon monoxide, oxygen, and molecular hydrogen to give the corresponding carbonyl (4), dioxygen (5), and dihydrogen (6) derivatives. Complex 3 also promotes the heterolytic bond activation of pinacolborane (HBpin), using the acyl oxygen atom as a pendant Lewis base. The hydride ligand and the Bpin substituent of the Fischer-type carbene of the resulting complex 7 activate the O–H bond of alcohols and water. As a consequence, complex 3 is a metal ligand cooperating catalyst for the generation of molecular hydrogen, by means of both the alcoholysis and hydrolysis of pinacolborane, via the intermediates 7 and 6.
Keywords:Acyl-NHC Osmium Cooperative System, Small Molecules, Heterolytic B-H, O-H Bond Activation
American Chemical Society
info:eu-repo/semantics/article