关于-(2,2,2-三氯亚乙基)羧酰胺与二环己基碳二亚胺之间杂环狄尔斯-阿尔德反应的历程问题：逐步两性离子环加成过程的一个新实例

On the Question of the Course of the Hetero Diels-Alder Reactions Between -(2,2,2-Trichloroethylidene)Carboxamides and Dicyclohexylcarbodiimide: A New Case of the Stepwise Zwitterionic Cycloaddition Process.

作者信息

Woliński Przemysław, Zawadzińska-Wrochniak Karolina, Dresler Ewa, Jasiński Radomir

机构信息

Department of Organic Chemistry and Technology, Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland.

Radom Scientific Society, Rynek 15, 26-600 Radom, Poland.

出版信息

Molecules. 2025 Jun 21;30(13):2692. doi: 10.3390/molecules30132692.

DOI:10.3390/molecules30132692

PMID:40649211

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12250618/

Abstract

The regioselectivity and the molecular mechanism of the Diels-Alder reactions between -(2,2,2-trichloroethylidene)carboxamides and dicyclohexylcarbodiimide were explored based on the ωB97xd/6-311G(d) (PCM) calculations. It was found that the reaction course is determined by polar local interactions. It is interesting that the most favored reaction channel is realized not via classical single-step Diels-Alder mechanism, but according to the stepwise scheme with the intervention of the zwitterionic intermediate. The details of the electron density redistribution along the reaction coordinate were explained using the ELF technique.

摘要

基于ωB97xd/6-311G(d)（PCM）计算，探究了-(2,2,2-三氯亚乙基)羧酰胺与二环己基碳二亚胺之间狄尔斯-阿尔德反应的区域选择性和分子机制。发现反应过程由极性局部相互作用决定。有趣的是，最有利的反应通道不是通过经典的单步狄尔斯-阿尔德机制实现的，而是根据两性离子中间体介入的分步方案实现的。使用ELF技术解释了沿反应坐标的电子密度重新分布的细节。