Azide click chemistry is popular within the biotech and pharmaceutical fields as it is highly selective, stable, efficient and stereospecific. The click reactions for these products are copper-catalysed azide-alkyne cycloaddition (CuAAC) OR copper-free azide-alkyne cycloaddition (SPAAC) of an azide with a structure constrained alkyne (BCN, DBCO) where the pure products (1,2,3-triazoles) can be isolated easily. These reactions work at very high rates and the results are fixed over a large range of temperatures, pH and functional groups.