Synthesis of vinyl iodide chain-end polymers via organocatalyzed chain-end transformation

Abstract

In the presence of alkynes (CHC–R²), iodide chain-end polymers (Polymer–I) were successfully transformed to vinyl iodide chain-end polymers (polymer–CHCR²–I) in a single step via organocatalysis. 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 R² moiety. 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 R³ moieties. 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.