N3-D-Lys(Fmoc)-OH is a click chemistry reagent equipped with an azide group that facilitates highly specific bioorthogonal reactions: biocompatibility, rapid action, and extreme specificity in biological environments. This compound can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing an alkyne group. It is also capable of strain-promoted alkyne-azide cycloaddition (SPAAC) with molecules that possess DBCO or BCN groups.