# Advances in Organic and Organic-Inorganic Hybrid Polymeric Supports for Catalytic Applications
## 2 Organocatalysed Non-Asymmetric Reactions
### Miscellaneous Examples  
A new porous polymerized organocatalyst with high surface area, hierarchical porosity, and superior chemical stability was prepared and employed as an efficient heterogeneous catalyst in the oxidation of alcohols. In detail, the porous polymerized organocatalyst **47** was synthesized from solvothermal polymerization of vinyl-functionalized 2,2,6,6-tetramethylpiperidine monomer **46** in the presence of AIBN at 100 \({}^{\circ}\)C, followed by oxidation with \(m\)-chloroperbenzoic acid (\(m\)-CPBA) (Scheme 20) [36]. Monomer **46** was synthesized by nucleophilic substitution reaction between 2,2,6,6-tetramethyl-4-piperdylamine and 4,\(A^{\prime}\)-(bromomethylene)-bis(vinylbenzene) (**45**), previously prepared starting from 4-vinylbenzaldehyde. The use of 1 mol % of **47** in oxidation of various substituted alcohols at 0 \({}^{\circ}\)C led to the corresponding aldehydes and ketones with very high conversions (>99%) and selectivities (96%->99%). The reaction with benzyl alcohol was also carried out with 0.1 mol % and 0.05 mol % of catalyst, obtaining a conversion of 99% after 10 and 20 h respectively. Furthermore, catalyst **47** was more active than TEMPO immobilized on MCM-41 [37]. The same conversions were achieved using polymers with superior surface area,obtained by copolymerization of monomer **46** and divinylbenzene. Catalyst **47** was used for five cycles without significant loss of activity. The first application of thiazolium-based compounds as catalysts for the etherification reaction of alcohols was reported [38]. Thiazolium hybrid material **49** was prepared by a radical reaction between a mercaptopropyl-modified SBA-15 mesoporous silica and large excess of bis-vinyl-thiazolium salt **48** (Scheme 21) and successively employed in the etherification reaction of 1-phenyl-ethanol under solvent-free conditions at 160 \({}^{\circ}\)C testing different gas phases (oxygen, air, nitrogen and argon). After 24 h, an almost quantitative conversion (93%) was observed in both oxygen and air with a better selectivity toward ether in air (86%) than oxygen (73%). Under a nitrogen or argon atmosphere, a decrease of conversion (55%, 57% respectively) and an increase of selectivity (93%, 91% respectively) were observed. Furthermore, thiazolium hybrid material **49** displayed higher conversion and selectivity compared to the analogous imidazolium-based material, thus showing that the nature of the \(N\)-heterocyclic ring had a determinant impact on the performances of the reaction. The authors proposed a possible reaction mechanism. The supported thiazolium-based material **49** was also used with success in the etherification reaction of benzyl alcohol and diphenylmethanol under air. Recycle experiments were carried out in the etherification reaction of 1-phenylethylanol; excellent catalytic performances were preserved in seven catalytic runs. A simple, green, and efficient strategy for the synthesis of benzoxazoles and benzothiazoles was developed [39] by using the mesoporous poly(melamine-formaldehyde) **50**[40; 41; 42] prepared starting from melamine and paraformaldehyde (Scheme 22). Polymer **50** acted as bifunctional catalyst and, under the optimized catalytic conditions, led to benzoxazoles and benzothiazoles with good and excellent yields (71%-99%) by reaction of substituted 2-aminophenols with benzaldehyde using dioxygen as oxidant. Traces of products were obtained using aliphatic aldehydes and 2-methyl-benzaldehyde. The authors proposed a possible reaction mechanism. The catalyst was used six cycles without significant loss of catalytic performance. Recently, [PERSON] et al. reported the first application of a supported base as catalyst for the phospha-Michael addition of phosphorus nucleophiles to a variety of electron-poor alkenes [43].