Epoxidation of Cyclooctene with Aqueous Hydrogen Peroxide Catalyzed by MolybdateBound to Colloidal Polymers

摘要

Epoxidation of cyclooctene in aqueous hydrogen peroxide was catalyzed by ammoniummolybdate in the absence of organic solvent. Typically 1.3 mol % of Mo(VI) bound to 60 nm colloidal anion exchange polymers catalyzed 90% conversion of cyclooctene to > 99% cyclooctene oxide by excess hydrogen peroxide in 24 h at 40 deg C. Only 12% epoxide was formed in the absence of colloidal particles. Under the same conditions styrene and cyclohexene gave complex product mixtures, and 1-octane did not react. The colloidal polymer supports enable oxidations of water-insoluble alkenes without use of organic solvents. Qualitatively the higher activity of the peroxomolybdate bound to latex than in aqueous solution may be attributed to the higher local concentrations of both the alkene and the catalyst in the latex.