Advances in 1,3-dipolar cycloaddition reaction of azides and alkynes - A prototype of "click" chemistry

Click chemistry, designated by Sharpless and his coworkers, is a modular approach that uses only the most practical and reliable chemical transformations. The Huisgen reaction, especially the newly developed copper(l)-catalyzed 1,2,3-triazole formation reaction between azides and alkynes, is regarded as the "cream of the crop" of click chemistry. In this review, we introduce the recent development of this reaction, and highlight some of its important applications in drug discovery, bioconjugation chemistry, materials development and surface modification.