Figure 2. In CuAAC, an azide-containing moiety (red) is reacted with an alkyne-containing moiety (blue)

Figure 2. In CuAAC, an azide-containing moiety (red) is reacted with an alkyne-containing moiety (blue) in the presence of a catalytic amount of copper (I) to produce a highly stable triazole ring. The triazole ring can be produced in near quantitative yields.