Strategies Towards the Synthesis of N2-Substituted 1,2,3-Triazoles

The chemistry of 1,2,3-triazoles gained much attention since the discovery of the copper catalyzed Alkyne-azide cycloaddition (CuAAC) reaction which delivers exclusively the 1,4-regioisomer in high yields. On the other hand there is still no universal methodology capable of delivering the N2 substituted regioisomer. The unique properties of these N2-substituted 1,2,3-triazoles have stimulated synthetic efforts on the developments of methodologies capable of delivering it in high yield and selectivity. These efforts are the subject of the presented review.