Amphiphobic surface-active ionic liquids as dynamic micellar phase-transfer catalysts for biphasic epoxidations

Abstract

We report on the synthesis of amphiphobic surface-active ionic liquids (FSAILs) containing fluorinated anions. The solubility and aggregation behavior of the FSAILs was determined in both aqueous hydrogen peroxide and in organic media. The FSAILs were applied as temperature-controlled micellar and phase transfer epoxidation catalysts by mixing the FSAIL with sodium tungstate in aqueous H₂O₂ solution. The epoxidation of cis-cyclooctene with aqueous hydrogen peroxide was studied in terms of catalyst activity, phase behavior and recycling. To deepen insights recycability and phase transfer, especially of the catalytically active species, characteristics of the micellar catalysis were investigated in detail over different reaction time periods. High-resolution ¹H-qNMR reveals a quantitative phase transfer of the FSAILs into the organic phase, while the additive remains in the aqueous phase. Additionally, the present tungsten species also remain fully in the aqueous phase as shown by ICP-MS analysis.