calculations suggest a 1,4-dipole behaviour (also viewed as a 1,7-dipole behaviour) for most diazoazoles when reacting with electron-rich alkenes; it is believed that the approach between 2-diazo-2H-imidazole and alkenes to give rise to the [4 + 2]-cycloadducts is quite asynchronous. Finally, some errors found in the literature concerning the reactivity of diazoazoles with alkoxy-ethenes have been corrected