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

采用自由基聚合和新单体共聚法制备了含有双极性非质子溶剂基团的可溶聚合物，如二甲亚砜、N，N-二甲基甲酰胺、四甲基脲、N，N-二甲基甲磺酰胺及其类似物。这些聚合物在液-液两相条件下作为有效的相转移催化剂。含苯乙烯单元的共聚物的催化活性普遍高于均聚物。结果表明，这些聚合物比它们的单体类似物更有效地提取了所有的碱金属阳离子，并且随着活性位点密度的增加，提取能力增强，表明它们具有协同作用。我们可以合理地假设，催化活性是由于聚合物的阳离子萃取能力和聚合物疏水区脱溶引起的阴离子活化。含有偶极非质子溶剂部分的不溶性聚合物以及部分烷基化聚l -亮氨酸和尼龙-66也表现出相转移催化活性。

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.