Intramolecular (sp3-hybridized) C-H Activation: Yttrium Alkyls versus Transient Yttrium Hydrides

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• 作者：Grigorii G. Skvortsov ; Georgii K. Fukin ; Alexander A. Trifonov ; Awal Noor ; Christian D&ouml ; ring ; Rhett Kempe
• 刊名：Organometallics
• 出版年：2007
• 出版时间：November 19, 2007
• 年：2007
• 卷：26
• 期：24
• 页码：5770 - 5773
• 全文大小：108K
• 年卷期：v.26,no.24(November 19, 2007)
• ISSN：1520-6041

文摘

Intramolecular sp³-hybridized C-H activation ofnovel yttrium alkyl and hydrido complexes supported by bulkyaminopyridinato ligands derived from deprotonated 2,6-(diisopropylphenyl)-[6-(2,6-dimethylphenyl)pyridin-2-yl]amine (Ap'-H) is reported. Reaction of YCl₃ with a 2-fold molar excess ofAp'K in THF afforded complex [Ap'₂YCl(thf)] (1). Alkylationof 1 with an equimolar amount of LiCH₂SiMe₃ in hexaneallowed isolation of the alkylyttrium derivative [Ap'₂YCH₂SiMe₃(thf)] (2) in 65% yield. Unexpectedly treatment of complex 2 with PhSiH₃ (toluene, 20 C) afforded the productof intramolecular sp³-hybridized C-H bond activation,Ap'(Ap'_-H)Y(THF) (3). Most likely a hydrid species is formedin the course of this reaction, which undergoes rapid C-Hactivation since 3 is formed from 2 directly about 500 timesslower than in the presence of 1 equiv of PhSiH₃. Molecularstructures of complexes 2 and 3 have been confirmed by X-raycrystal structure analysis.