Construction Of Catalytic System Immobilized In Silica-supported Ionic Liquid Films And Their Application In Henry Reaction

Henry reaction is one of classical carbon-carbon bond formation reaction, the product β-nitro alcohols can be subjected to a variety of useful molecules via oxidation, reduction, elimination reactions. In recent decades, great progress has been made in Henry reaction and developed a large number of excellent catalysts. However, compared with which have been reported, less catalyst can be recycled, and most of which have difficulty in separating and poor cyclability, which limits its application in industry. Therefor, it is significant to design a simple preparation, efficient performance and recyclable catalyst. Based on this idea, three kinds of novel catalysts immobilized in silica-supported ionic liquid films were designed and prepared, and their catalytic effects were investigated on the Henry reaction. Certainly, the recycling performance of these three catalysts were also studied.1. Building of catalyst system of guanidine salt immobilized in silica-supported ionic liquid films and their application in Henry reactionA type of catalyst system of guanidine salt immobilized in silica-supported ionic liquid films has been prepared with silica as the carrier, and then applied in the Henry reaction using 2-nitrobenzaldehyde and nitromethane as substrates. Next the effects of the catalyst with different loading of ionic liquids and guanidine salt on catalytic performances were studied, and then solvents, temperature and other factors on catalytic performances were also examined. The results have showed that the catalytic effect of G1@ILs/Silica is the best(yield up to 92%), the ratio of the guanidine salt(mmol), ionic liquid(mmol) and silica(g) is 1.0 / 0.5 / 1, and use ethanol as solvent, the reaction conducted at 25 ℃ for 12 h. In optimizing conditions, aromatic aldehydes with different substitute groups were studied and the results have showed that the yield of aromatic aldehydes with electron withdrawing groups is better than that of aromatic aldehydes with electron-donating groups. Finally, the recovery of catalyst performance the was studied and the catalyst displayed certain reusability after the catalyst was recycled for four times.2. Building of catalyst system of chiral bidentate amine metal complex immobilized in silica-supported ionic liquid films and their application in Henry reactionA type of catalyst system of chiral bidentate amine metal complex immobilized in silica-supported ionic liquid films has been prepared with silica as the carrier, and then applied in the asymmetric Henry reaction using 4-nitrobenzaldehyde andnitromethane as substrates. Next the effects of the catalyst with different loading of ionic liquids and bidentate amine ligand, specific surface area and pore size of the supported catalyst, the preparation methods of the catalysts, ligand with different structure, metal salt on catalytic performances were studied, and then time, temperature, solvents and other factors on catalytic performances were also examined. The results showed that the catalytic effect of Cu L1@ILs/Silica(1) is the best(yield up to 95%, ee up to 82%), the ratio of the L1(mmol), ionic liquid(mmol) and silica(g) is 0.8 / 0.3 / 1, and use ethanol as solvent, the reaction conducted at 0 ℃ for 48 h. In optimizing conditions, aromatic aldehydes with different substitute groups were studied and achieved better yield and enantioselectivity that the yield up to 95% and ee up to 91%. Finally, the recovery of catalyst performance the was studied and the catalyst displayed certain reusability after the catalyst was recycled for five times.3. Building of catalyst system of chiral tetradentate ligand metal complex immobilized in silica-supported ionic liquid films and their application in Henry reactionA type of chiral tetradentate ligand metal complex catalysts and catalyst system of chiral tetradentate ligand metal complex immobilized in silica-supported ionic liquid films has been prepared with silica as the carrier, and then applied in the asymmetric Henry reaction using 4-nitrobenzaldehyde and nitromethane as substrates. Next the effects of the ligand with different structure, metal salt, time and temperature, and other factors on catalytic performances were studied. Preliminarily, the recovery of catalyst performance was studied and the catalyst displayed certain reusability after the catalyst was recycled for five times.