In order for CAN to be a robust CPS technique, peptides need to be templated together through a bioorthogonal reaction that will not cause unintended side reactions during conjugation. For this purpose, we chose to use strain-promoted alkyne-azide cycloaddition (SPAAC) over copper-catalyzed azide-alkyne cycloaddition (CuAAC) because SPAAC avoids potential copper-catalyzed oxidation during the click reaction. In addition, we wanted to perform one-pot templating and NCL and expected that the presence of copper within NCL conditions may cause side-product formation (e.g., during in situ thioester formation ).