Unprecedented Addition of Tetrahydroborate to an Osmium鈥揅arbon Triple Bond

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• 作者：Mar铆a L. Buil ; Juan J. F. Cardo ; Miguel A. Esteruelas ; Israel Fern谩ndez ; Enrique O帽ate
• 刊名：Organometallics
• 出版年：2014
• 出版时间：June 9, 2014
• 年：2014
• 卷：33
• 期：11
• 页码：2689-2692
• 全文大小：305K
• 年卷期：v.33,no.11(June 9, 2014)
• ISSN：1520-6041

文摘

The complexes [OsHCl(鈮Ph)(IPr)(PR₃)]OTf (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CF₃SO₃; PR₃ = PⁱPr₃ (1), PPh₃ (2)) react with NaBH₄ in tetrahydrofuran to give OsH₂Cl(畏²-H-BCH₂Ph)(IPr)(PR₃) (PR₃ = PⁱPr₃ (3), PPh₃ (4)). The mechanism of addition has been studied by means of isotopic labeling experiments and DFT calculations. The results indicate that the boron ligand is generated by hydroboration of the Os鈮 triple bond of 1 and 2 and subsequent B鈥揌 bond activation of the resulting alkylborane. The original hydride ligand does not participate in the hydroboration process. However, it plays a secondary role in the B鈥揌 bond activation.