Synthesis of Polymeric analogues of Dipolar Aprotic Solvents and Their Use as Phase Transfer Catalysts

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Soluble polymers containing dipolar aprotic solvent moieties such as dimethyl sulfoxide, N,N-dimethylformamides, tetramethylurea, N,N-dimethylmethanesulfonamides and their analogues were prepared by free radical polymerization and copolymerization of corresponding new monomers. These polymers served as effective phase transfer catalysts for several reactions under liquid-liquid two-phase conditions. The catalytic activity of the copolymers containing styrene unit was generally higher than that of homopolymers. It was found that these polymers extract all alkali metal cations more effectively than their monomeric analogues, and that the extraction ability increased with increasing density of active sites, suggesting their cooperative effect. It is reasonable to assume that the catalytic activity is due to both cation extraction ability of the polymers and the activation of anions caused by desolvation in the hydrophobic regions of polymers. Insoluble polymers containing dipolar aprotic solvent moieties as well as partially alkylated poly-L-leucine and Nylon-66 also exhibited phase transfer catalytic activity.