大学化学 >> 2022, Vol. 37 >> Issue (7): 2110047.doi: 10.3866/PKU.DXHX202110047

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基于量子化学计算探究丁-1-烯-3-炔亲电加成反应的机理和选择性

金小玲, 刘强(), 惠新平   

  • 收稿日期:2021-10-15 录用日期:2022-01-06 发布日期:2022-02-25
  • 通讯作者: 刘强 E-mail:liuqiang@lzu.edu.cn
  • 作者简介:刘强, Email: liuqiang@lzu.edu.cn
  • 基金资助:
    兰州大学教育教学改革研究重点项目(2020019)

Mechanisms and Selectivities of Electrophilic Addition Reaction to But-1-en-3-yne Based on Quantum Chemistry Calculation

Xiaoling Jin, Qiang Liu(), Xinping Hui   

  • Received:2021-10-15 Accepted:2022-01-06 Published:2022-02-25
  • Contact: Qiang Liu E-mail:liuqiang@lzu.edu.cn

摘要:

通过量子化学计算模拟了丁-1-烯-3-炔与亲电试剂HBr、HCl和Br2的亲电加成反应。计算结果表明:丁-1-烯-3-炔发生亲电加成反应时,既可以发生1, 2-加成反应,也可以发生1, 4-加成反应。1, 4-加成反应决速步骤活化能低,产物累积二烯烃的生成速度快,受动力学控制;1, 2-加成反应决速步骤活化能高,产物共轭二烯烃的生成速度慢,受热力学控制。在极性溶剂水和氯仿中,反应决速步骤的能垒均有所降低,亲电加成反应更容易发生。

关键词: 丁-1-烯-3-炔, 亲电加成, 氢卤化, 溴化, 反应机理, 量子化学计算

Abstract:

The electrophilic addition reactions to but-1-en-3-yne were calculated using quantum chemistry. The results show that hydrohalogenation and bromination of but-1-en-3-yne produce a mixture of 1, 2- and 1, 4-addition products. The products' distribution of 1, 4-addition and 1, 2-addition is governed by kinetic or thermodynamic control, respectively. 1, 4-Addition products, the allenes, although thermodynamically less stable, are formed faster with a lower activation barrier. However, 1, 2-addition products, the conjugated dienes, which are a bit more stable than the 1, 4-addition products, are thermodynamic. The solvent model predicts a lowering of the energy barrier for the rate-determining steps of the reactions in H2O and CHCl3 solution.

Key words: But-1-en-3-yne, Electrophilic addition, Hydrohalogenation, Bromination, Reaction mechanisms, Quantum chemistry calculation

MSC2000: 

  • G64