Amphiphilic Mesoporous Poly(Ionic Liquid) Immobilized Heteropolyanions Towards the Efficient Heterogeneous Epoxidation of Alkenes with Stoichiometric Hydrogen Peroxide

New mesoporous poly(ionic liquid)s (MPILs) that feature a pure polycationic framework and tunable hydrophobicity were synthesized through the free-radical polymerization of alkyl-functionalized ionic liquids (ILs) and bisvinylimidazolium salt. Phosphotungstic (PW) anions were immobilized firmly on these MPILs with a high dispersion and density. The obtained catalyst was effective in the epoxidation of cis-cyclooctene with stoichiometric hydrogen peroxide (H2O2) to give a high yield (>98%) and a remarkable H2O2 efficiency (>98%). The maximum turnover number and turnover frequency was 2375 and 685h(-1), respectively. The catalyst can be recovered easily by filtration and reused with stable activity. Other alkenes can be converted with high yields. The extraordinary performance was attributed to the pure ionic porous framework with an enhanced hydrophobicity that not only provides strong cation-anion interactions towards the stable immobilized PW anions with a high dispersion but also enables the strong affinity of the catalyst with both the substrate and oxidant.