6-yl-hex-1-ene自由基环合成反应机理的理论研究  

Theoretical investigation on the cyclization reaction mechanism of 6-yl-hex-1-ene radical

作　　者：于海涛[1] 

机构地区：[1]黑龙江大学化学化工与材料学院,哈尔滨150080

出　　处：《黑龙江大学自然科学学报》2009年第4期516-521,共6页Journal of Natural Science of Heilongjiang University

基　　金：国家自然科学基金资助项目(20301006)

摘　　要：应用密度泛函理论对6-yl-hex-1-ene自由基环合成反应做了详细的理论研究。通过对随反应坐标变化几个关键变量变化的讨论,揭示了6-yl-hex-1-ene自由基在进行环合成反应时区域选择性的高低;同时,也分析了在6-endo-trig和5-exo-trig反应途径中的热力学和动力学势垒的变化,以及六元环产物和五元环产物的环张力对热力学过程和动力学过程可能产生的影响。结果表明在6-yl-hex-1-ene自由基环合成过程中,经过5-exo-trig反应途径生成环应力较大的五元环产物具有动力学优势,是主要的动力学产物。同时分析结果也表明,可以利用在反应过程中进攻角变量的变化来定性地判断反应选择性的优势通道,并用以定性地解释Baldwin规则的结论。A theoretical study on the radical cyclization reaction mechanism of 6-yl-hex-1-ene was performed theoretically. By predicting the changes of several key parameters along reaction coordinate, the regioselectivity of the radical cyclization reaction was investigated while the changes of thermochemistry and kinetic barriers of 6-endo-trig and 5-exo-trig reaction pathways were analyzed. Also, the effect of ring strain of six-and five-membered ring products were investigated on the thermodynamic and kinetic processes. The computed results indicate that the 5-exo-trig channel leading to a five-membered ring product with larger ring strain energy dominates the reaction process, and therefore, it is a kinetic product. Furthermore, the computation results also indicate that the dominant reaction channel can be judged by the attack angle of reaction pathways, and also, it can be used to explain the conclusion of the Baldwin rules.

关 键 词：反应机理 6-yl—hex-1-ene自由基 密度函数理论 自由基环合成 

分 类 号：O641.12[理学—物理化学]