Foreword

As befitting a Nobel Prize in Chemistry, the development of the click chemistry concept by Sharpless, Meldal and Bertozzi has revolutionized chemical sciences. By defining a set of strict criteria for highly efficient coupling reactions, click chemistry has become a rallying cry for the development of new efficient coupling reactions as well as the rediscovery of old, nearly forgotten chemical coupling reactions that, with modifications, also can be termed click reactions. This growing arsenal of click reactions has found broad use in all fields of chemical sciences, ranging from biochemistry and chemical biology to supramolecular chemistry and polymer science. The utility of click chemistry for polymer synthesis goes back to a chance meeting with Barry Sharpless at a conference in Sydney in 2002. I had the extreme pleasure of speaking with Barry at the 2002 Cornforth Symposium and it was Barry’s description of early click chemistry that set off a lightbulb for me. Click chemistry fulfilled many long-standing needs for the synthesis of functional macromolecules. Up until that time, most polymer-based reactions were either very complicated or led to partial modifications, often leading to inseparable mixtures of polymers with different chain-end or side-chain functionality. The distinctive features of macromolecules compared with small molecules (e.g., the number of functional groups, molecular weight distribution, and purification techniques) made the identification of polymer synthesis protocols that proceed with structural fidelity and high levels of functional group compatibility a grand challenge, holding back the whole field. Hence it is no surprise that click chemistry has flourished in polymer science ever since its introduction. From the early days of demonstrating the promise of click chemistry, the field has evolved to be part of a standard toolbox of polymer scientists for the preparation of functional polymer structures with recent focus shifting to the use of click chemistry for discovering functional polymers for specific applications. As click chemistry in polymer science has matured in recent years, it is a perfect time for this comprehensive book on Click Chemistry in Polymer Science that provides chapters on the different types of click reactions that have been applied in polymer science, chapters on the use of click chemistry for making complex polymer architectures and chapters on the use of click chemistry for specific classes of polymers. Altogether the book provides a clear and broad overview of click chemistry in polymer science and will serve as an important handbook for those active in the area and for those interested in becoming active in the area. Many years ago, Barry Sharpless taught me a wonderful quote inspired by Sir John Cornforth – “It does, for example, no good to offer an elegant, difficult and expensive process to an industrial manufacturing chemist, whose ideal is something to be carried out in a disused bathtub with the product being collected continuously through the drain hole in 100% purity and yield”. Barry’s key message of efficiency, simplicity, and orthogonality – hallmarks of all good click chemistry – resonates even more loudly today for polymer researchers.

Craig Hawker, UC Santa Barbara