The strategic introduction of propargyl azide on key intermediates have been an efficient way to prepare 1H-1,2,3-triazolyl nucleosides, antibiotics, and enzyme inhibitors. Those limited reported examples, cannot be compared with the enormous amount of bioactive 1H-1,2,3triazoles reported since 2005. One of the reasons for the limited application of the Banert cascade is the lack of a complete understanding of the molecular processes involved in the reaction. That knowledge will be critical for developing more efficient reactions to obtain 4,5-disubstituted 1,2,3-triazoles. Within the framework of the theoretical study, density functional theory (DFT) has emerged as a powerful tool to elucidate reaction mechanisms and intricate details of the elementary steps involved in the divergent pathways of several reactions. Currently, only one theoretical study about the sigmatropic pathway mechanism of the Banert cascade has been reported. In that work, the [3,3]-sigmatropic rearrangement for the conversion of propargylic azide into triazafulvene has been proved as the rate determining step. Therefore, we wanted to study the Banert cascade to provide the theoretical basis of the reaction mechanism.