摘要
频哪醇重排是本科有机化学课程的重要内容,但学生对重排机理、区域选择性和基团迁移规律不能很好地理解掌握。为了加强学生对频哪醇重排反应的理解,我们设计了一个利用计算化学方法解决有机化学问题的实验。通过直观的图像和具体的数据清楚地展现出:能形成稳定碳正离子中间体的底物主要以分步重排机理进行,而不能形成稳定中间体的底物则按协同重排机理进行。计算结果验证了反应的区域选择性取决于邻二醇质子化羟基的位置以及基团的迁移能力,明确了基团迁移能力的顺序为氢>芳基>烷基,并从微观角度对其进行了合理解释。
Pinacol rearrangement is an important topic in undergraduate organic chemistry courses,but students often struggle to fully understand and grasp the rearrangement mechanism,regioselectivity and group migration aptitude.In order to enhance students’comprehension of pinacol rearrangement reactions,we design an experiment that utilizes computational chemistry methods to address organic chemistry problems.Through intuitive visuals and specific data,the experiment clearly demonstrates that substrates capable of forming stable carbocation intermediates primarily undergo stepwise rearrangement mechanisms,while those unable to form stable intermediates undergo concerted rearrangement mechanisms.The computational results validate that the regioselectivity of the reaction depends on the protonation site of the neighboring diol hydroxyl group and the group migration ability,and it unequivocally establishes the order of group migration ability as hydrogen>aromatic>alkyl.Furthermore,a rational explanation for this order is provided from a microscopic perspective.
作者
赵容浩
梁一钒
史梦瑶
朱荣秀
张冬菊
Ronghao Zhao;Yifan Liang;Mengyao Shi;Rongxiu Zhu;Dongju Zhang(School of Chemistry and Chemical Engineering,Shandong University,Jinan 250100,China)
出处
《大学化学》
CAS
2024年第4期305-313,共9页
University Chemistry
基金
山东省本科教学改革研究项目(计算化学在大学基础化学教学中的应用)
山东大学教学改革项目(2023Y061,2022Y072)。
关键词
频哪醇重排
反应机理
迁移能力
密度泛函理论计算
Pinacol rearrangement
Reaction mechanism
Migratory aptitude
DFT calculations
