An Alternative Method for the Synthesis of N-Pentafluorophenyl Triazolium Salts

A route for the synthesis of 1,2,4-triazolium salts via oxidation of a thione precursor is demonstrated. N-Pentafluor-ophenyl-substituted salts are produced in 20-63% overall yields. Isolation and purification of the azolium salts are simplified compared to the traditional synthetic route. Late-stage selection of the counterion allows the synthesis of a variety of salts from a parent thione. The salts have been compared in Stetter and cross-benzoin reactions with an appreciable counterion effect in both reactions.

Automated summary

A route for the synthesis of 1,2,4-triazolium salts via oxidation of a thione precursor is demonstrated, with overall yields of 20-63%. Isolation and purification of the salts are simplified compared to traditional synthetic routes, and a variety of salts can be synthesized by late-stage selection of the counterion. These salts exhibit an appreciable counterion effect in both Stetter and cross-benzoin reactions.