Synthesis and phase-transfer catalytic activity of polystyrene resins containing hydroxyl groups and crown ether structures

Abstract

Polystyrene resins with crown ether structures and hydroxyl groups adjacent to the macrorings were prepared by the reaction of crosslinked polystyrene resins containing epoxide groups with monoaza-15-crown-5 or monoaza-18-crown-6. The polymeric catalysts with 30–40% ring substitution exhibited high activity for the dehydrobromination of 2-bromoethylbenzene with aqueous KOH under tri-phase conditions. The active site of the catalysts was suggested to have a structure in which the K + ion was bound by the cooperative coordination of the crown ring donors and the alkoxide anions in the sidearms.