Copper(I)-Catalyzed Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Azidoformates and Aryl Terminal Alkynes.

The copper(I)-catalyzed azide-alkyne cycloaddition reaction has been extensively studied and widely applied in organic synthesis. However, the formation of 1,2,3-triazoles with electron-deficient azide has been a challenging problem. In this report, we have demonstrated the formation of regioselective 1,4-disubstituted 1,2,3-triazoles from various types of aryl terminal alkynes and azidoformates, which are electron-deficient azides, using a commercialized [Cu(CH3CN)4]PF6 copper(I) catalyst under mild conditions.