Heterogeneous copper catalyst for the cycloaddition of azides and alkynes without additives under ambient conditions.

A new copper catalyst was developed by immobilizing copper nanoparticles in aluminum oxyhydoxide fiber. The catalyst showed high catalytic activity for the (3+2) Huisgen cycloaddition of nonactivated alkynes as well as activated ones with various azides at room temperature. The catalyst was recycled five times without significant loss of activity.