Solid-phase synthesis of iterative RAFT single unit monomer insertion adducts

In this article, we disclose the use of a solid-phase methodology to synthesise iterative RAFT single unit monomer insertion (SUMI) adducts. This methodology features a reversible thiocarbonylthio protecting group and radical chain growth of vinyl monomers, with minimal purification required during the synthesis. To achieve this, a RAFT chain transfer agent was immobilised on a common peptide synthesis resin via the “R-group” in the first instance. Using an oxygen-tolerant PET-RAFT methodology, we then extended the iterative synthesis of indene-maleimide SUMI adducts to 18 units with minimal dispersity, completely unprecedented in SUMI chemistry. Furthermore, as we demonstrate, this solid-phase methodology can be generalised to other maleimide derivatives and other solid-phase resins.