Click chemistry as a connection tool: Grand opportunities and challenges

Although the concept of click chemistry was proposed more than twenty years ago, the research progress of click chemistry has emerged with great vitality, and this year's Nobel Prize in chemistry has once again highlighted the importance of the field of click chemistry. Click chemistry is a reaction in which a variety of molecules are quickly and reliably synthesized by piecing together small units. In particular, it emphasizes the development of new combinatorial chemistry methods based on the synthesis of carbon-heteroatomic bonds and the simple and efficient acquisition of molecular diversity through these reactions. Based on the superior reaction characteristics of click chemistry, click chemistry methods for production are advancing toward precision, simplicity, and high returns, especially in producing polymer materials and some bright biomedical applications. Here, we describe the development logic of typical click reactions with different substrates and catalysts. The latest technologies of click chemistry in the structure control and functional properties of polymers, as well as in the field of biomedicine and its expanding applications, are discussed. Finally, we identify the challenges of click chemistry in reaction mechanisms and engineering applications, and suggest potential future development directions in the future.