Sulfenate anions as organocatalysts for benzylic chloromethyl coupling polymerization via C=C bond formation.

Organocatalytic polymerization reactions have a number of advantages over their metal-catalyzed counterparts, including environmental friendliness, ease of catalyst synthesis and storage, and alternative reaction pathways. Here we introduce an organocatalytic polymerization method called benzylic chloromethyl-coupling polymerization (BCCP). BCCP is catalyzed by organocatalysts not previously employed in polymerization processes (sulfenate anions), which are generated from bench-stable sulfoxide precatalysts. The sulfenate anion promotes an umpolung polycondensation via step-growth propagation cycles involving sulfoxide intermediates. BCCP represents an example of an organocatalyst that links monomers by C=C double bond formation and offers transition metal-free access to a wide variety of polymers that cannot be synthesized by traditional precursor routes.