不是反芳香性增益，而是增加的非同步性增强了环庚三烯酮的狄尔斯-阿尔德反应活性。

Not antiaromaticity gain, but increased asynchronicity enhances the Diels-Alder reactivity of tropone.

作者信息

Tiekink Eveline H, Vermeeren Pascal, Hamlin Trevor A

机构信息

Department of Theoretical Chemistry, Amsterdam Institute of Molecfular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, Amsterdam 1081 HV, The Netherlands.

出版信息

Chem Commun (Camb). 2023 Mar 23;59(25):3703-3706. doi: 10.1039/d3cc00512g.

DOI:10.1039/d3cc00512g

PMID:36880301

Abstract

Tropone is an unreactive diene in normal electron demand Diels-Alder reactions, but it can be activated carbonyl umpolung by using hydrazone ion analogs. Recently, the higher reactivity of hydrazone ion analogs was ascribed to a raised HOMO energy induced by antiaromaticity (L. J. Karas, A. T. Campbell, I. V. Alabugin and J. I. Wu, . ., 2020, , 7083). We show that this is incorrect, and that the activation barrier is lowered by increased asynchronicity.

摘要

在正常电子需求的狄尔斯-阿尔德反应中，环庚三烯酮是一种不活泼的二烯，但通过使用腙离子类似物可以实现羰基极性翻转使其活化。最近，腙离子类似物的较高反应活性被归因于反芳香性导致的最高占据分子轨道（HOMO）能量升高（L. J. 卡拉斯、A. T. 坎贝尔、I. V. 阿拉布丁和J. I. 吴，《美国化学会志》，2020年，第142卷，第7083页）。我们表明这是不正确的，并且活化能垒是通过增加非同步性而降低的。