Summary.
The regioselectivity of 1,3-dipolar cycloaddition reactions of 1-aza-2-azoniaallene salts with α,β-unsaturated nitriles such as acrylonitrile or cyclohexylidene acetonitrile afforded only 1,2,4-triazolium salts via addition to the nitrile group, while the other expected pyrazolium salts were not observed. Moreover, 1-aza-2-azonia-allene salts reacted with other competitive systems such as α-iminonitrile derivatives yielding only triazolium salts via addition to the nitrile and not to the imino group. Treatment of cumulene with 3-pyridylnitrile afforded the pyridinium salt. However, 2,3-dimethyl-5-(2,6-dimethoxyphenyl)-[1,2,4]triazole could be prepared from cumulene and 2,6-dimethoxybenzonitrile. Some reactions of nitriles with 1-aza-2-azonia-allene salts prepared from 1,2,3-indantrione and 9-acetylphenanthrene are discussed.
Similar content being viewed by others
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Amer, A. Regioselective Synthesis of Substituted Triazolium Salts via 1,3-Dipolar Cycloaddition Reactions. Monatshefte für Chemie 134, 1577–1584 (2003). https://doi.org/10.1007/s00706-003-0041-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00706-003-0041-1