Regioselective living polymerization of allylcyclohexane and precise synthesis of hydrocarbon block copolymers with cyclic units†
Abstract
Precise control over macromolecular structures is a central goal and remains a great challenge in synthetic polymer chemistry. We report herein the living isomerization polymerization of allycyclohexane (ACH) using α-diimine nickel catalysts with high regioselectivity. The influences of catalyst structure, cocatalyst, and temperature on ACH polymerization were studied in detail. The macromolecular structure of polyallycyclohexanes (PACHs) was precisely controlled by living polymerization in combination with high regioselectivity under optimized conditions. A mechanistic model involving the 2,1-insertion selectivity of ACH and chain walking was proposed. Well-defined polyallycyclohexane-b-poly(1-hexene) copolymers (PACH-b-PH) with cyclic units were synthesized by sequential monomer addition.