Discovery of the RAFT/MADIX Process: Mechanistic Insights and Polymer Chemistry Implications

This Perspective outlines the observations leading to the discovery of the degenerative exchange of xanthates and related thiocarbonylthio derivatives. It compares this process with the older Kharasch reaction and discusses the key ability to reversibly store active radicals in a nonreactive form. Implications for the synthesis of polymers beyond the RAFT/MADIX technology are discussed, namely, the modification of industrial polymers, the synthesis of novel monomers, oligomers, and surfactants from biosourced feedstocks, especially through an alliance with the powerful metathesis reaction. The synthesis of trialkoxysilane cross-linkers for sol-gels and the use of boronates for the construction of well-defined sequences by controlled insertion of single monomers are discussed briefly.