Improvement of the polyoxometalate's performance in the asymmetric oxidation of styrene via combined with chiral ionic liquid

• Stereo-potency of polyoxometalates can be improved via simply combined POM with chiral ILs.
• R-1-Phenyl-1,2-ethanediol is the main oxidation product of styrene in presence of H2O2.
• CILs may function as chiral recognizer on the enantiomers of vicinal diols.

The efficiency and enantioselectivity of polyoxometalate (POM) in the oxidation of styrene with H2O2 could be improved via simply combined the POM with the chiral ionic liquids (CILs), which consist of the quaternized alkyl bromide salts (with lengths of C-8, C-12, and C-16) derived from natural chiral S-nicotine. The hybrids showed synergistic advantages between POM and CILs, achieving a complete conversion of styrene after 1 h of mild reaction and a relatively high selectivity for R-(−)-1-phenylethane-1, 2-diol with 72% yield and 96% ee. Further fluorescence analysis illustrated that CILs might serve for the enantiomeric recognition of R- than S-enantiomers.

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