Oxidation of Alkenes with Aqueous Potassium Peroxymonosulfate and No OrganicSolvent

摘要

Aqueous potassium peroxymonosulfate oxidizes water-immiscible alkenes at roomtemperature in the absence of organic solvent. Acidic (pH equals or less than 1.7) solutions of 2KHS05(dot)KHSO4(dot)K2SO4 in water produced the epoxide from cyclooctene and diols from all other reactive alkenes investigated. Adjustment of initial pH to equal or less than 6.7 with NaHCO3 enabled selective epoxidations of 2,3-dimethyl-2-butene, 1-methylcyclohexene, cyclohexene, styrene, and betamethylstyrene. The order of decreasing reactivity of alkenes was: 2,3-dimethyl-2-butene > 1-methylcyclohexene > cyclohexene > cyclooctene > alpha-methylstyrene > beta-methylstyrene > styrene > p-methylstyrene > allylbenzene. 1-Octene and tetrachloroethylene did not react. Phase-transfer catalysts, a colloidal cationic polymer, and a cationic surfactant microemulsion had little effect on the reaction.