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Updated: Mar 26, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Cationic 1,2,3-Triazolium Alkynes: Components To Enhance 1,4-Regioselective Azide-Alkyne Cycloaddition Reactions
Zaira Monasterio1, Maialen Sagartzazu-Aizpurua1, José I Miranda1
1Departamento de Química Orgánica-I, Universidad del País Vasco UPV/EHU , Joxe Mari Korta R&D Center, Avda Tolosa-72, 20018 San Sebastián, Spain.
Abstract:
4-Alkynyl-1,2,3-triazolium cations undergo thermal [3 + 2] cycloaddition reactions with azides roughly 50- to 100-fold faster than comparable noncharged alkynes. Further, the reaction is highly 1,4-regioselective (dr up to 99:1) owing to the selective stabilization of 1,4-TS transition states via conjugative π-acceptor assistance of the alkyne triazolium ring. The novel cationic triazolium alkynes also accelerate the CuAAC reaction to provide bis(1,2,3-triazoles) in an "ultrafast" way (<5 min).
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