Polymer-Supported Phase-Transfer Catalysts. Crown Ethers and Cryptands Bonded by a Long Alkyl Chain to a Polystyrene Matrix

Article abstract of DOI:10.1021/jo00323a029

The synthesis of ω-aminononyl-substituted 18-crown-6 and <2.2.2>cryptand is described.These are easily bonded to chloromethylated polystyrene cross-linked with varying amounts of p-divinylbenzene.The polymer-bound polyethers can be successfully used as catalysts (0.01 molar equiv) in anion-promoted phase-transfer reactions.As is the case for the analogous soluble systems, the catalytic activity of the cryptands is higher than that of the crown ethers and quaternary onium salts.Due to their high chemical stability, polymer-bound polyethers are more advantageous than polymer-bound quaternary onium salts and can be recycled several times with no chemical degradation.However, loss of mechanical properties due to the grinding of the polymer matrix remains a problem.Methods allowing titration of polyether centers on the resin are also described.