Fmoc-N-amido-PEG5-azide is a PROTAC linker of the PEG class, used in the synthesis of PROTAC molecules. This compound functions as a click chemistry reagent due to its azide group, enabling copper-catalyzed azide-alkyne cycloaddition reactions (CuAAc) with molecules containing alkyne groups. Additionally, it can participate in strain-promoted alkyne-azide cycloaddition reactions (SPAAC) with molecules that have DBCO or BCN groups.