Click Chemistry beyond Metal‐Catalyzed Cycloaddition

Abstract No copper needed : In recent years, a large number of metal‐free click reactions have been reported based on thiol‐ene radical additions, Diels–Alder reactions, and Michael additions. In this Minireview, special attention is given to the advantages and limitations of the different methods to evaluate whether they have the potential to surpass the overwhelming success of the copper(I)‐catalyzed azide‐alkyne cycloaddition. magnified image The overwhelming success of click chemistry encouraged researchers to develop alternative “spring‐loaded” chemical reactions for use in different fields of chemistry. Initially, the copper(I)‐catalyzed azide‐alkyne cycloaddition was the only click reaction. In recent…