Thiol-Ene ‘Click Chemistry’: Discovery to Applications

Thiol-ene Click Chemistry or thiol-yne Click Chemistry, characterized by the radical-mediated addition of thiols to alkenes or alkynes, has emerged as a powerful and versatile tool in synthetic chemistry due to its high efficiency, specificity, and mild reaction conditions. This method, often initiated by light or thermal activation, results in the formation of robust carbon–sulfur bonds and thus making it an ideal tool for easy and high-yielding construction of complex molecular architectures. Thiol-ene click chemistry is extensively used in polymer science for creating well-defined networks, functionalizing surfaces, and synthesizing hydrogels. Additionally, it has significant applications in materials science, drug delivery systems, and bioengineering, where its biocompatibility and orthogonality are particularly advantageous. This chapter explores the core principles of thiol-ene and thiol-yne click chemistry and highlights its diverse applications, emphasizing its role in advancing the design and synthesis of innovative materials and its impact on various technological and biomedical fields.