Heterogeneous azide–alkyne click chemistry: towards metal-free end products

Heterogeneous copper catalyzed azide–alkyne click chemistry (CuAAc) has been a quickly emerging research field during the last couple of years as it shows many advantages in comparison to its homogeneous counterpart. In this Minireview, an overview of the state-of-the-art is presented for the first time. For the sake of completeness, not only successful heterogeneous supports but also systems that particularly failed will be discussed. Furthermore, the future prospects and challenges with regard to the application of heterogeneous CuAAC are highlighted.