Application of modified polystyrenes as phase transfer catalysts
Polimery 1994, No 9, 538
The method of synthesis of effective phase-transfer catalysts based on modified polystyrene has been developed. There were obtained ammonium catalysts in which the active ammonium group was linked to PS matrix with methylene chains comprising 2, 4, 5, 6, 8 or 12 carbon atoms. The catalysts were tested in the following reactions carried out under phase transfer conditions: N-alkylation of carbazole; O-alkylation of phenols and alcohols; substitutionreaction of dichlorocyclopropane (Mąkosza's reaction) to cyclohexene,a-methylstyrene and N-vinylcarbazole; and reactions of dichloroacetylene (DCA)with carbazole, imidazole and benzanilide. The effect of methylene chain lengthon the activity of the catalysts was characterized. The catalyst with sixmethylene groups in the chain was more effective than the commonly usedcatalysts in the reaction of DCA with carbazole, i.e. than triethylbenzylammoniumchloride (TEBA) and dimethyl sulphoxide (DMSO).
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