1,2-Diaza-1,3-butadienes: just a nice class of compounds, or powerful tools in organic chemistry? Reviewing an experience

This paper reviews our nearly twenty-five years' activity on 1,2-diaza-1,3-butadienes and shows that these compounds are powerful tools in organic chemistry. In fact, alpha-substituted-, alpha-oxo-, and alpha,beta-unsaturated-hydrazones, have been obtained from 1,2-diaza-1,3-butadienes, as have pyrroles, pyrazoles, imidazoles, thiazoles, selenazoles, 1,2,3-thiadiazoles, 1,2,3-selenadiazoles, pyridazines, pyrazines, 1,2,4-triazines, and mixed heterocyclic systems.