Molecular dynamics of bicyclo[2.2.0]hex-2-ene ring opening and its polar derivative: allowed vs. forbidden pathways

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Authors: Zhixin Qin, Qingyang Zhou, Rong-Kai Wu, K. N. Houk
Cited by: 1
References: 60

Abstract

We employed density functional theory, CCSD(T) and CASSCF computations, along with quasi-classical molecular dynamics simulations, to explore the ring opening of bicyclo[2.2.0]hex-2-ene and its 1-amino-4-cyano derivative. While the overall reaction is a formally forbidden 4-electron disrotatory electrocyclization, both conrotatory and disrotatory pathways operate for the hydrocarbon, the latter involving a HOMO-LUMO crossing and diradical transition state. Quasi-classical simulations reveal the presence of non-statistical dynamic behavior involving a short-lived intermediate in the formally forbidden process. For the donor/acceptor-substituted derivative, the charge separation induced by substitution eliminates orbital symmetry restrictions, enabling a sterically favored disrotatory pathway.

Fields of Study & Subjects

Cyclization and Aryne Chemistry Advanced Chemical Physics Studies Organic Chemistry Cycloaddition Reactions

Publication details

Journal / source
Chemical Science
Publisher
Royal Society of Chemistry (RSC)
Volume
17
Issue
13
Pages
6644–6652
Publication date
1 January 2026
Language
EN