High Quality Content by WIKIPEDIA articles! The Azide-Alkyne Huisgen Cycloaddition is a 1,3-dipolar cycloaddition between an azide and a terminal or internal alkyne to give a 1,2,3-triazole. Rolf Huisgen was the first to understand the scope of this organic reaction. American chemist K. Barry Sharpless has referred to this cycloaddition as "the cream of the crop" of click chemistry.