Synthesis and Characterization of Bulky Cationic Arylalkylaluminum Compounds

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• 作者：Tomasz Klis ; Douglas R. Powell ; Lukasz Wojtas ; Rudolf J. Wehmschulte
• 刊名：Organometallics
• 出版年：2011
• 出版时间：May 9, 2011
• 年：2011
• 卷：30
• 期：9
• 页码：2563-2570
• 全文大小：920K
• 年卷期：v.30,no.9(May 9, 2011)
• ISSN：1520-6041

文摘

The cationic m-terphenyl-substituted organoaluminum compounds [Dipp*AlEt][CH₆B₁₁Cl₆] (3; Dipp* = 2,6-(2,6-i-Pr₂C₆H₃)₂C₆H₃鈭?, [DcpAlEt][CH₆B₁₁Cl₆] (4; Dcp = 2,6-(2,6-Cl₂C₆H₃)₂C₆H₃鈭?, [Dipp*AlEt][CH₆B₁₁I₆] (5), and [DcpAlEt][CH₆B₁₁I₆] (6) have been obtained by ethide elimination through trityl or preferably silylium salts from the precursors Dipp*AlEt₂ (1) and DcpAlEt₂ (2). The crystal structures of compounds 3鈭?b>5 reveal the presence of cation鈭抋nion adducts involving two halides of the carborane anions, and the NMR spectroscopic data and solubility properties indicate such an interaction for 6. The interactions of the hexaiodocarborane anion with the [Dipp*AlEt]⁺ cation are stronger than those of the hexachlorocarborane anion. Interestingly, cation路路路anion contacts are preferred to intramolecular Al路路路Cl interactions in the Dcp species 4. Compound 4 forms the bis-amine adduct [DcpAlEt(NH₂t-Bu)₂][CH₆B₁₁I₆] (8) upon exposure to tBuNH₂, and compounds 3 and 4 slowly catalyze the alkylation of benzene with 1-hexene. The compounds have been characterized by ¹H, ¹³C, and ¹¹B NMR spectroscopy and by X-ray crystallography in the case of 1鈭?b>5, 7, and 8.