Polymers often have been built in highly defined molecular configurations and conformations. In many modern functional materials, the arrangement of their molecules dictates their properties and uses. As the structure of functional polymers becomes more complex, their directed synthesis is more elaborate, in particular aiming at the exact positioning of functional groups onto sites of medium and large molecules. Click chemistry, often described as being analogous to the fastening (“click”) of two ends of a buckle, is a highly valuable tool for simple reactions between large molecules and molecule fragments, thus representing an ideal method for generating complex macromolecules and materials.