1,2,3-Triazole formation by cycloaddition

^{Click the structures and reaction arrows in sequence to view the 3D models and animations respectively}

The azide and the alkyne undergo 1,3-dipolar cycloaddition to yield the 1,2,3-triazole.This regiochemistry is favoured by copper catalysis. This reaction, Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC), has been popularised by “click chemistry” which was awarded the Nobel Prize in Chemistry in 2022.

H. Jalani, A. Karagöz and S. Tsogoeva, Synthesis (Stuttg)., 2016, 49, 29–41.