The unimolecular decarboxylation of 6-nitrobenzisoxazole-3-carboxylate ion is markedly catalyzed by cationic polysoaps: partially laurylated poly(4-vinylpyridine) and poly(2-ethyl-1-vinylimidazole). The polymers which acted as efficient catalysts invariably caused the hypsochromic shift of the absorption maximum of methyl orange, and increased dissociation of dichlorophenolindophenol and the fluorescent emission of l-anilinonaphthalene-8-sulfonate. The linear correlation observed between the logarithm of the rate constant and the wavenumber of the absorption maximum of methyl orange indicates the importance of the hydrophobic environment of polymer micelles in the rate enhancement. The decarboxylation reaction in aprotic solvents, which was performed in connection with the environmental effect of polysoaps, is relatively insusceptible to small amounts of water. The polysoap catalysis can be further enhanced by adding hydrophobic anions and organic solvents (methanol, tert-butyl alcohol, acetone). The catalytic efficiency of the polysoap is related to the formation of the hydrophobic domain and the desolvation of the anion is of less importance than in other micelle-catalyzed bimolecular reactions involving oxy anionic nucleophiles.
All Science Journal Classification (ASJC) codes
- Organic Chemistry