Synthesis of vinyl iodide chain-end polymersviaorganocatalyzed chain-end transformation

In the presence of alkynes (CH C-R²), iodide chain-end polymers (Polymer-I) were successfully transformed to vinyl iodide chain-end polymers (polymer-CHCR²-I) in a single stepviaorganocatalysis. This reaction is completely metal-free and easy to carry out without using special reagents or special conditions. The polymers encompassing polyacrylates and polymethacrylate, and additional functionalities (e.g., OH and CF₃) were also incorporated into the R²moiety. The obtained Polymer-CHCR²-I further served as a useful precursor for copper-catalyzed cross-coupling reactions with various thiols (R³-SH) to yield vinyl sulfide chain-end polymers (polymer-CHCR²-SR³) with various R³moieties. Interestingly, under selected conditions, this organocatalysis also offered block-like copolymers containing a conjugated oligo-alkyne segment and a non-conjugated polyacrylate segment. Exploiting the unique structure, the block-like copolymer was used as an efficient dispersant of carbon nanotubes.