University Chemistry ›› 2022, Vol. 37 ›› Issue (7): 2110047.doi: 10.3866/PKU.DXHX202110047

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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

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