Synthesis of 3-Substituted Indazoles from Arynes and <i>N</i>-Tosylhydrazones

Abstract

Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in moderate to good yields. The reaction appears to involve a dipolar cycloaddition of in situ generated diazo compounds and arynes.