A Study on Polymers and Their Organic Synthesis |
Polymeric reagents offer a variety of unique benefits.Intra-molecular reactions, such as the cyclization of peptides or Dieckmanncyclizations can be applied by attaching the reactive molecules at distantpoints along a polymer chain. In contrast, if the reactive molecules aresecured in close approprinquity on a polymeric support then intermolecularreactions take place as illustrated for a ketone synthesis. Besides suchproximity effects, mutual effects can also be oppressed, e.g. in theaccumulation of a 2:1 complex of a crown ether and an alkali metal ion. Thehydrolysis of an ester with polyvinyl imidazole gives a wide demonstration ofhydrophobic intercommunications. The simple dialysis of polymer-bound andlow-molecular compounds by filtration is another significant benefit.