Facile Synthesis of Fully Substituted 1,2,4‐Triazoles via [3+2] Cycloaddition of Nitrileimines with Amidine under Transition Metal‐Free Conditions

An efficient synthesis of densely 1,2,4‐triazoles has been achieved by [3+2] cycloaddition of nitrileimides with amidine hydrochlorides under transition metal‐free conditions. This method features mild reaction conditions, wide substrate scope and good functional group tolerance. A series of aryl, heterocyclic and alkyl substituted 3‐CF 3 ‐1,2,4‐triazoles were synthesized smoothly under the promotion of NaHCO 3 and yield up to 96%. In addition, both gram‐scale reaction and synthetic transformations are smoothly elaborated to indicate the utility of this reaction.