Thiol–Ene Chemistry

Thiol-ene reactions are most commonly photoinitiated and generally utilize a stoichiometric reaction mixture of thiols and enes. The radical initiated thiol-ene reaction is unique in that it is the only known radical step growth polymerization. Thiol-ene systems have significant advantages over acrylic polymerizations in that they are relatively insensitive to oxygen inhibition and exhibit significantly lower levels of shrinkage and stress. These properties along with many more that are highlighted in this chapter have led to thiol-ene systems being the focus of extensive research and development efforts for applications in biomaterials, nanotechnology, and numerous other high-performance polymers. Regardless of the reaction conditions or mechanism, the thiol-ene reaction results in the anti-Markovnikov addition of a thiol to an ene functional group. The chapter also discusses the chemoselectivity and side reactions as well as the applications and representative examples from the literature of thiol-ene systems.