ariations on the Bergman Cyclization Theme: Electrocyclizations of Ionic Penta-, Hepta-, and Octadiy
DOI
10.1021/jacs.3c06691
Abstract
The Bergman cyclization of (Z)-hexa-3-ene-1,5-diyne to form the aromatic diradical p-benzyne has garnered attention as a potential antitumor agent due to its relatively low cyclization barrier and the stability of the resulting diradical. Here, we present a theoretical investigation of several ionic extensions of the fundamental Bergman cyclization: electrocyclizations of the penta-1,4-diyne anion, hepta-1,6-diyne cation, and octa-1,7-diyne dication, leveraging the spin-flip formulation of the equation-of-motion coupled cluster theory with single and double substitutions (EOM-SF-CCSD). Though the penta-1,4-diyne anion exhibits a large cyclization barrier of +66 kcal mol–1, cyclization of both the hepta-1,6-diyne cation and octa-1,7-diyne dication along a previously unreported triplet pathway requires relatively low energy. We also identified the presence of significant aromaticity in the triplet diradical products of these two cationic cyclizations.
Document Type
Article
Publication Date
9-25-2023
Publisher Statement
Copyright © 2023 The Authors. Published by American Chemical Society. This publication is licensed under
CC-BY 4.0.Recommended Citation
Dominic A. Sirianni, Xinli Song, Salmika Wairegi, Evan B. Wang, Sebastian A. Mendoza-Gomez, Adam Luxon, Maxwell Zimmerley, Ariana Nussdorf, Michael Filatov, Roald Hoffmann, and Carol A. Parish. Variations on the Bergman cyclization theme: Electrocyclizations of ionic penta-, hepta-, and octadiynes. Journal of the American Chemical Society 2023 145 (39), 21408-21418. DOI: 10.1021/jacs.3c06691