Modular Synthesis of Monofluorinated 1,2,4-Triazoles/1,3,5-Triazines via Defluorinative Annulations of N-CF3 Imidoyl Chlorides

Ring-fluorinated azaheterocycles have wide applications in agrochemicals, pharmaceuticals, and synthesis, which prompt continuous endeavors to expand such heterocyclic families. However, monofluorinated triazaheterocycles have hardly been explored. This work reported a novel and modular synthesis of monofluorinated 1,2,4-triazoles and 1,3,5-triazines, which utilizes N-CF₃ imidoyl chlorides as unique polyfluoro synthons and their defluorinative annulations with hydrazines/imidazines. Further modifications of these fluorinated heterocycles highlight the potential of the method for accessing functional molecules.