高等学校化学学报 ›› 2016, Vol. 37 ›› Issue (12): 2199-2205.doi: 10.7503/cjcu20160489

• 物理化学 • 上一篇    下一篇

Rh(Xantphos)L催化氢化肉桂醛和降冰片二烯间转移加氢甲酰化反应的理论研究

杨永胜, 杨欣, 田之悦, 薛英()   

  1. 四川大学化学学院, 成都 610064
  • 收稿日期:2016-07-08 出版日期:2016-12-10 发布日期:2016-11-24
  • 作者简介:联系人简介: 薛 英, 女, 博士, 教授, 博士生导师. 主要从事计算化学研究. E-mail:yxue@scu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21573153, 21173151)资助

Theoretical Studies on the Mechanisms of Transfer Hydroformylation Between Hydrocinnamaldehyde and Norbornadiene Catalyzed by Rh(Xantphos)L Complexes

YANG Yongsheng, YANG Xin, TIAN Zhiyue, XUE Ying*()   

  1. College of Chemistry, Sichuan University, Chengdu 610064, China
  • Received:2016-07-08 Online:2016-12-10 Published:2016-11-24
  • Contact: XUE Ying E-mail:yxue@scu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.21573153, 21173151)

摘要:

采用密度泛函理论方法M11-L/6-31G(d,p)对氢化肉桂醛与降冰片二烯(nbd)在活化催化剂a [Rh(Xantphos)L, L=苯甲酸根, Xantphos=4,5-双二苯基膦-9,9-二甲基氧杂蒽]催化下发生转移加氢甲酰化反应生成主产物苯乙烯(3)的反应机理进行理论研究. 结果表明, 参与反应的醛类化合物在α碳(α-C)上应至少连接一个氢原子, 这可以减少醛类反应物和抗衡离子的空间排斥作用. 通过反应能垒图可见, 受体nbd发生加氢甲酰化反应, 促进了脱氢甲酰化反应的进行, 进而促使整个转移加氢甲酰化循环不可逆进行. 还研究了氢化肉桂醛发生脱羰化生成少量副产物苯乙烷(4)的机理过程. 结果表明, 苯甲酸根作为抗衡离子抑制了脱羰化反应的竞争, 理论计算得到脱氢甲酰化反应的选择性为苯乙烯(3)∶苯乙烷(4)>99∶1. 简单醛(如丙醛)在活化催化剂a催化下更易于发生脱羰反应而不是脱氢甲酰化反应.

关键词: 转移加氢甲酰化, 氢化肉桂醛, 降冰片二烯, 苯甲酸根抗衡离子, 密度泛函理论

Abstract:

The mechanism of transfer hydroformylation reactions of hydrocinnamaldehyde with norbornadiene(nbd) catalyzed by the catalyst a[Rh(Xantphos)L] complex at M11-L/6-31G(d,p) was calculated(Pathway A). The α-C in the reactive aldehyde molecules actually bonds with one hydrogen atom at least to reduce the steric interaction between the aldehyde reactant and counterion section in C—H oxidative addition step. A little of alkane products observed experimentally, the mechanism of reactive course of decarbonylation of hydrocinnamaldehyde(Pathway B) was calculated. The theoretical study indicates that decarbonylation reaction is suppressed and the selectivity for dehydroformylation is calculated to be(styrene∶phenylethane>99∶1) with benzoate as counterion. The calculation results show that simple aldehyde propanal would prefer dehydroformylation reaction rather than decarbonylation reaction catalyzed by active catalyst a. Based on the reactive energy barrier profile, the hydroformylation of acceptor nbd accelerated the occurrence of dehydroformylation and made the whole transfer hydroformylation irreversible.

Key words: Transfer hydroformylation, Hydrocinnamaldehyde, Norbornadiene, Benzoate counterion, Density functional theory

中图分类号: