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Updated: Oct 21, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Synthesis of bicyclic vinyl triazenes by Ficini-type reactions
Carl Thomas Bormann1, Farzaneh Fadaei-Tirani1, Rosario Scopelliti1
1Laboratory of Supramolecular Chemistry, EPFL SB ISIC LCS, BCH 3307, 1015 Lausanne, Switzerland. kay.severin@epfl.ch.
Abstract:
Cyclic olefins with triazene functions can display interesting reactivity, but synthetic access to these compounds is limited thus far. Herein, we describe the synthesis of cyclobutenyl triazenes fused to cyclopentanone or cyclohexanone rings. The bicyclic compounds are obtained by Lewis acid-catalyzed [2 + 2] cycloaddition reactions of 1-alkynyl triazenes and enones. In the presence of Me2AlCl, bicyclic [4.2.0] triazenes rearrange into [3.2.1] ring systems. The triazene function in the latter can be used for further functionalizations. Notably, we show that vinyl triazenes can serve as substrates for Pd-catalyzed cross-coupling reactions with arylboronic acids.
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