Regioselectively Electrochemical Synthesis of N²-Selective C-H Amination of Ethers with N-Tosyl 1,2,3-Triazole via Triazole Radical Cation

A regioselective electrochemical C-H amination method to synthesize N²-substituted 1,2,3-triazole using easily accessible ethers has been developed. Various substituents, including heterocycles, have a good tolerance, and 24 examples were obtained in moderate to good yields. Control experiments and DFT calculation investigations demonstrate that the electrochemical synthesis undergoes a N-tosyl 1,2,3-triazole radical cation process promoted by the single-electron transfer of the lone pair electrons of the aromatic N-heterocycle, and the desulfonation is responsible for the high N²-regioselectivity.