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Updated: May 31, 2026

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Inverse electron demand Diels-Alder reactions of 1,2,3-triazines: pronounced substituent effects on reactivity and
Erin D Anderson1, Dale L Boger
1Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Abstract:
A systematic study of the inverse electron demand Diels-Alder reactions of 1,2,3-triazines is disclosed, including an examination of the impact of a C5 substituent. Such substituents were found to exhibit a remarkable impact on the cycloaddition reactivity of the 1,2,3-triazine without altering, and perhaps even enhancing, the intrinsic cycloaddition regioselectivity. The study revealed not only that the reactivity may be predictably modulated by a C5 substituent (R = CO(2)Me > Ph > H) but also that the impact is of a magnitude to convert 1,2,3-triazine (1) and its modest cycloaddition scope into a heterocyclic azadiene system with a reaction scope that portends extensive synthetic utility, expanding the range of participating dienophiles. Significantly, the studies define a now powerful additional heterocyclic azadiene, complementary to the isomeric 1,2,4-triazines and 1,3,5-triazines, capable of dependable participation in inverse electron demand Diels-Alder reactions, extending the number of complementary heterocyclic ring systems accessible with implementation of the methodology.
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