An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B-H and O-H Bond Activation

作者：Bolano Tamara; Esteruelas Miguel A^*; Gay M Pilar; Onate Enrique; Pastor Isidro M; Yus Miguel

来源：Organometallics, 2015, 34(15): 3902-3908.

DOI：10.1021/acs.organomet.5b00418

The hexahydride complex OsH6((PPr3)-Pr-i)(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)((PPr3)-Pr-i)(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.

• 出版日期2015-8-10