Polymer-Supported Oligo(oxyethylene)s, Sulfoxides, and Crown Ethers in Nucleophilic Substitution Reactions

The efficiency of polymer analogues of oligo(oxyethylene)s and sulfoxides in the activation of nucleophilic substitution reactions were compared by testing to the reaction between sodium phenoxide and 1-bromooctane in 1,4-dioxane. With polymer analogues of crown ethers and polymer networks having the pseudo-crown ether structure the polymer effect can be achieved, i.e. a higher activation efficiency of the polymer analogue (in the L-S system) compared with the efficiency of the unimmobilized compound (in the homogeneous system). The results suggest that several molecules of the linear activator or of side active groupings (chains) on the polymer having the podand structure take part in the formation of the activation site (for the complex formation or solvation of the cation).