An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B鈥揌 and O鈥揌 Bond Activation
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- 作者：Tamara Bola帽o ; Miguel A. Esteruelas ; M. Pilar Gay ; Enrique O帽ate ; Isidro M. Pastor ; Miguel Yus
- 刊名：Organometallics
- 出版年：2015
- 出版时间：August 10, 2015
- 年：2015
- 卷：34
- 期：15
- 页码：3902-3908
- 全文大小：409K
- ISSN：1520-6041
文摘
The hexahydride complex OsH6(PiPr3)2 (1) activates the C鈥揙Me 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鈥揌 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.