# Advances in Organic and Organic-Inorganic Hybrid Polymeric Supports for Catalytic Applications
## 4 Metal-Catalysed Non-Asymmetric Reactions
### Miscellaneous Examples  
In order to increase the catalytic activity toward the synthesis of cyclic carbonate, by cycloaddition reaction of CO\({}_{2}\) to epoxides, bifunctional catalysis based on both Lewis acids and quaternary ammonium salts can be used. Ionic polymer microsphere (see also Scheme 10) bearing Co(III)-Salen moiety were used for this scope [97]. Particularly, the new bifunctional solid catalyst TBB-Bpy@Salen-Co **155** was synthesized by grafting a Salen-Co III Schiff base **154** onto cross-linked TBB-Bpy ionic polymer **153**, prepared by reaction between TBB (1,2,4,5-tetrakis(bromomethyl)-benzene,) and Bpy (4,4\({}^{\prime}\)-bipyridine) in a one-pot solvothermal method (Scheme 59). The catalyst was applied in the cycloaddition reaction of CO\({}_{2}\) to various epoxides at 60 \({}^{\circ}\)C-80 \({}^{\circ}\)C, even at low CO\({}_{2}\) pressure (0.2 MPa) under solvent-free conditions and without any additives. The corresponding cyclic carbonates were obtained with high conversions and excellent selectivities. The TON was approximately 300-500 moles of product per mole of catalyst based on Co. A possible synergistic mechanism that involved the active sites of catalyst functionalized with Co atoms and Br was proposed. The catalyst recyclability was investigated by cycloaddition of propylene oxide. The solid catalyst was recovered by filtration and reused for five cycles without any significant loss of activity or selectivity. ICP-AES elemental analysis revealed 4.62 wt % Co in the catalyst recovered after five runs, which was very similar to that found for the fresh catalyst (4.71 wt % Co), thus indicating the heterogeneous nature of the catalyst. Similar ionic polymers were also used to stabilize AuNPs for oxidation reactions. [PERSON] et al. reported the application of gold nanoparticles supported on a nanoporous ionic organic network (PION) as catalysts for alcohol oxidation (Scheme 60) [98]. For this reason, the PION **156**, having a high ionic density (three cation-anion pairs per unit), was synthesized by nucleophilic substitution between commercial 1,3,5-tris(bromomethyl)benzene and 1,2-bis(4-pyridyl)ethylene. Gold nanoparticles (Au NPs) were supported on PION **156** by ion exchange reaction with AuCl\({}_{4}-\)ions and successive chemical reduction with freshly prepared aqueous solution of NaBH\({}_{4}\). The new hybrid material thus obtained, denoted as **157**, presented quite small Au NPs (mean size: 2.2 nm) and homogeneously dispersed on the polymer support. In presence of catalyst **157** and in toluene as solvent, the aerobic oxidation of a saturated alcohols was carried out affording the corresponding ketones with high yields and selectivities. **Scheme 60. Synthesis of gold nanoparticles supported on nanoporous ionic organic network **157** and its use as catalysts for alcohol oxidation. The recyclabily of catalyst **157** was investigated by cyclohexanol oxidation. It was recovered by centrifugation and reused over five runs maintaining its catalytic activity. Furthermore, the liquid phase of the reaction mixture was also collected by hot filtration after the first run and analyzed by inductively coupled plasma mass spectrometry. A very low amount of dissolved gold (0.1% of the total gold) was detected in the solution at the end of the reaction. [PERSON] et al. investigated the efficiency of twelve different composites (**158a-d**, **159a-d**, **160a-d**), constituted by gold nanoparticles immobilized onto imidazolium-based supported ionic liquid like phases (AuNPs-SILLPs), as catalysts for microwave-assisted selective oxidation of 1-phenyl-ethanol in water with H\({}_{2}\)O\({}_{2}\) as oxidant (Scheme 61) [99]. SILLPs with different variables [100; 101], including the functionalization degree, resin morphology (gel-type vs. macroporous resins) and the alkyl substitution of the imidazolium moiety (-Me, -But, or -Dec), were evaluated.