# Advances in Organic and Organic-Inorganic Hybrid Polymeric Supports for Catalytic Applications
## 4 Metal-Catalysed Non-Asymmetric Reactions
### Epoxidation of Alkenes
The preparation of POSS-derived mesoporous poly(ionic liquids) **109a-e** was carried by free radical copolymerization of octa(N-vinylimidazole-silsesquioxane)(POSS-IM, **107**) with 1,1-(butane-1,\(A\)-diyl)-bis(3-vinylimidazolium) dibromide (**108**), by varying the molar ratio of bis-vinylimidazolium salt **108** to POSS-IM **107**. This latter was previously synthesized via nucleophilic substitution reaction of chlorine groups of octa(3-chloropropyl silsesquioxane) with vinyl imidazole. Afterwards, the anion-exchange of polymeric frameworks **109a-e** with the Keggin-type H\({}_{3}\)PW\({}_{12}\)O\({}_{40}\) provided mesoporous POM-based ionic hybrids **110a-e**. The hybrids **110a-e** were applied in H\({}_{2}\)O\({}_{2}\)-based epoxidation of cyclootene at 70 \({}^{\circ}\)C in acetonitrile as solvent. The materials **110d** and **110e**, exhibited the best results (both 99% conversion and 100% selectivity). Furthermore, low conversions were obtained with corresponding POSS-free polyoxometalate-based ionic hybrids and with homogeneous H\({}_{3}\)PW\({}_{12}\)O\({}_{40}\). The material  
Figure 37: Synthesis of amphiphilic mesostructured polyoxometalate-based ionic hybrids **110a–e** and their use as catalysts in the epoxidation of alkenes. **110d** was also tested with different substrates obtaining good catalytic activities (51.6%-91.7% conversion) and selectivities (57.3%-99.2%). The catalytic reusability of **110d** was studied in epoxidation of cyclooctene. The catalyst, recovered by filtration, was reused for three run tests without loss of catalytic activity. The result of ICP-AES analysis showed that less than 1.1 wt % W of **110d** has been leached into the reaction media. The study of amphiphilic porous POSS incorporated polyoxometalate-paired polymeric hybrids as catalysts for epoxidation reactions was expanded investigating the synthesis and application of the new hybrid catalyst **112** (Scheme 38) [66]. This material was prepared by radical copolymerization of octavinyl POSS, 3-dodecyl-1-vinylimidazolium bromide and 3-propionic acid-1-vinylimidazolium bromide in 1:3:5 mole ratio, respectively, followed by ion exchange in aqueous solution with the previously prepared H\({}_{3}\)[PO\({}_{4}\)(WO\({}_{3}\))\({}_{4}\)]. Based on previous studies, this molar ratio permitted to obtain the optimum specific surface (24 cm\({}^{2}\cdot\)g\({}^{-1}\)) and pore volume (0.175 cm\({}^{3}\cdot\)g\({}^{-1}\)). Higher molar ratio of dodecyl imidazole ionic liquid to carboxylic acid functionalized imidazole ionic liquid led to less porous systems, most probably due to the blockage of the channels because of dodecyl groups. Good to excellent activities (49%-99% conversion) and high selectivities (94%-100%) were obtained, applying the catalyst **112** in epoxidation of various alkenes with H\({}_{2}\)O\({}_{2}\) in acetonitrile as solvent at 70 \({}^{\circ}\)C. Finally, the reusability of **112** was evaluated on the epoxidation of cyclooctene. The catalyst was recovered by centrifugation and reused for four runs without observing loss in catalytic activity. Moreover, results of ICP-AES analysis showed that about 3.1 wt % W in the catalyst has been leached into the reaction media in the first run, but in the following runs, the leaching was negligible. Recently, additional series of POSS-derived mesostructural and amphiphilic copolymer-polyoxometalate catalysts were successfully synthesized using ionic liquids bearing hydrophobic alkyl chains as the building blocks [67]. Particularly, the catalysts **114a-d** were prepared by free radical copolymerization of octavinyl POSS (o-POSS) with ([3-octyl-1-vinylimidazolium]Br) by varying the molar ratio of liquid ionic (IL) to o-POSS and successively carrying out the anion-exchange with H\({}_{3}\)PW\({}_{12}\)O\({}_{40}\) in aqueous solution (Scheme 39).