Navarro-Vázquez Armando, Prall Matthias, Schreiner Peter R
Institute of Organic Chemistry, Justus-Liebig-University, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany.
Org Lett. 2004 Aug 19;6(17):2981-4. doi: 10.1021/ol0488340.
The cyclization reactions of polyunsaturated systems such as enediynes, enyne-allenes, as well as many others, can be structurally related to the Cope reaction and grouped into two branches: 6pi (e.g., Cope, allenyl-Cope) and [2sigma + 4pi] systems (e.g., Bergman, Myers-Saito). After extensive computional (BCCD(T)/cc-pVDZ//UBLYP/6-31G) examination of a large set of Cope-related reactions, we derive the following simple rule: biradical intermediates are involved along the reaction path if they are stabilized by allylic resonance or aromaticity.
多不饱和体系的环化反应，如烯二炔、烯炔-联烯以及许多其他体系，在结构上可能与科普反应相关，并可分为两个分支：6π体系（如科普反应、烯丙基-科普反应）和[2σ + 4π]体系（如伯格曼反应、迈尔斯-斋藤反应）。在对大量与科普反应相关的反应进行广泛的计算研究（BCCD(T)/cc-pVDZ//UBLYP/6-31G）之后，我们得出以下简单规则：如果双自由基中间体通过烯丙基共振或芳香性得到稳定，则在反应路径中会涉及到它们。
