高等学校化学学报 ›› 1997, Vol. 18 ›› Issue (7): 1067.

• 论文 • 上一篇    下一篇

卤代羰基叶立德:“推-拉”稳定作用对四苯基环戊二烯酮与卡宾的脱氧反应的影响(英文)

程津培1, 王洪星1, 还振威1, 谭嫦娥1, Landgrebe John. A.2   

  1. 1. 南开大学化学系, 天津 300071;
    2. Kansas大学化学系, Lawrence, KS66045, USA
  • 收稿日期:1997-02-05 出版日期:1997-07-24 发布日期:1997-07-24
  • 作者简介:CHENG Jin-Pei, male, age of 48, Ph. D. Professor.

Halocarbonyl Ylide: the Effect of “Push-Pull”Stabilization on Deoxygenation of Tetraphenylcyclopentadienone in Carbene Reaction

CHENG Jin-Pei1, WANG Hong-Xing1, HYAN Zhen-Wei1, TAN Chang-E1, Landgrebe John. A.2   

  1. 1. Department of Chemistry, Nankai University, Tianjin 300071;
    2. Dapartment of Chemistry, Kansas University, Lawrence, Kansas 66045, U.S.A.
  • Received:1997-02-05 Online:1997-07-24 Published:1997-07-24

摘要: 研究了四苯基环戊二烯酮与三溴甲基苯基汞(二溴卡宾的前体化合物)的卡宾反应,发现该反应可给出比通常有立体障碍的酮要高得多的脱氧(以脱CO的形式)产率. 本文从羰基叶立德中间体的“推-拉”稳定作用以及该中间体的构象和电子分布的角度出发,并结合产物分析对这一反常现象进行了讨论,发现在潜芳香结构的羰基化合物与二卤卡宾的反应中,有可能由于“推-拉”作用形成具有芳香结构的羰基是中间体,该中间体由于正负电荷及以较好的分散以及其接近0°/90°型的构象,有效地阻碍了分子间环加成和分子内电环化这两个竞争反应的进行,从而使脱氧途径成为该反应的主渠道. 本项研究进一步揭示了一些尚未被人了解的反应规律,合理地解释了反应机理.

关键词: 羰基叶立德, 二卤卡宾, &ldquo, 推-拉&rdquo, 稳定作用, 反应机理

Abstract: An unexpectedly high yield of carbon monooxide as a deoxygenationproduct of carbonyl compound was obtained in the reaction of tetraphenyl-cyclopentadienone with dibromocarbene using phenyl tribromomethyl mercury asthe carbene precursor.This unique phenomenon is rationalized in terms of thepush-pull stabilization gained from the interaction between the partially aromaticcyclopentadienide moiety and the positively charged dibromomethylene moiety inthe dihalocarbonyl Ylide-like transition state.

Key words: Carbonyl ylide, Dihalocarbene, Push-pull stabilization, Reaction mech-anism

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