Regioselective intramolecular rearrangements in 1,2-bis(areneazo)cycloalkenes via triazolium imide 1,3-dipoles: examples of a new Fischer indole-type rearrangement. Azolium 1,3-dipoles. Part 2

Abstract

1,2-Bis(areneazo)cycloalkenes (2)(6 carbons and higher) when heated or treated with acid rearrange to hydro derivatives of fused 2,4-diarylcyclopolyeno[d][1,2,3]triazoles (3). The rearrangement, which was regioselective and Intramolecular, occurred through a 1,2,3-triazolium Imide 1,3-dipole form of the substrates (2). Synthesis, structural effects, a variable-temperature 270 MHz n.m.r. search for intermediates, and some kinetic studies are reported. The reaction is a new variation of the Fischer Indole reaction.