Boryltrihydroborate: Synthesis, Structure, and Reactivity as a Reductant in Ionic, Organometallic, and Radical Reactions

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• 作者：Kyoko Nozaki ; Yoshitaka Aramaki ; Makoto Yamashita ; Shau-Hua Ueng ; Max Malacria ; Emmanuel Lacte ; Dennis P. Curran
• 刊名：Journal of the American Chemical Society
• 出版年：2010
• 出版时间：August 25, 2010
• 年：2010
• 卷：132
• 期：33
• 页码：11449-11451
• 全文大小：236K
• 年卷期：v.132,no.33(August 25, 2010)
• ISSN：1520-5126

文摘

Reaction of lithium 1,3-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaborol-2-ide with borane·THF provides the first boryl-substituted borohydride: lithium [1,3-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaborol-2-yl]trihydroborate. The compound is fully characterized by ¹¹B, ¹H, and ⁷Li NMR spectra and other means, and these data are compared to neutral and anionic benchmark compounds. The compound crystallizes as a dimer complexed to four THF molecules. The dimer lacks the bridging B−H bonds seen in neutral boranes and is instead held together by ionic Li---HB interactions. A preliminary scan of reactions with several iodides shows that the compound participates in an ionic reduction (with a primary-alkyl iodide), an organometallic reduction (Pd-catalyzed with an aryl iodide), and a radical reduction (AIBN-initiated with a sugar-derived iodide). Accordingly the new borylborohydride class may share properties of both traditional borohydrides and isoelectronic N-heterocyclic carbene boranes.