Synthesis and phase-transfer catalytic activity of polymer-supported poly(ethylene glycol)s

Abstract

Polymer-supported poly(ethylene glycol)s with diol structures were prepared by the reaction of poly(ethylene glycol) (PEG) with crosslinked polystyrene resins containing epoxide groups, in the presence of NaH. The polystyrene-bound PEGs had both singly bound structures, produced by a 1:1 reaction between the epoxide groups and PEG, and doubly bound structures, produced by the reaction of one mole of PEG with two moles of the epoxides. The fraction of singly bound structures depended on the percentage of ring substitution of the resins, the spacer chain and the length (n) of the PEG oxyethylene unit. Supported PEGs, prepared from 20–40% ring-substituted resins with spaced epoxides and PEGs of n = 4−6, were rich in singly bound structures, and exhibited high phase-transfer catalytic activity for dehydrobromination of organic bromides in the presence of aqueous KOH.