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.