The representative reaction of click chemistry is copper catalyzed azide alkyne cycloaddition. The concept of click chemistry has made a great contribution to the field of chemical synthesis. Due to its excellent characteristics of high yield and no side effects, it has become one of the most useful and attractive synthetic concepts in many fields such as drug development and biomedical materials. The specific application in polypeptides is that polypeptides contain azide or alkyne groups, which can be efficiently linked with fluorescence, protein, DNA and other molecules. There are several common compounds to choose from.

Fmoc - 4 – azidophenylalanine   Fmoc - Phe(N3) - OH;

Fmoc – Azidohomoalanine

Fmoc - D – propargylglycine  Fmoc - D - Pra - OH

Fmoc - L - propargylglycine    Fmoc - L - Pra - OH

Fmoc - Lys(N3) – OH Fmoc - azidolysine;  Fmoc - lys(azide);

Azidoacetic acid

6-Azidohexanoic acid

Propiolic acid