Design Mesoporous Rare Earth Lewis Acid Catalyst In An Aqueous Medium And Clean Organic Synthesis Research

According to viewpoints of energy and materials saving, diminishment ofpollution, and environmental protection based on "Green Chemistry", it has beenproved it is easier and more efficient to separate heterogeneous Lanthanide catalystsfrom reaction system and reuse in comparison with homogeneous Lanthanidecatalysts, which could reduce cost of products and also the environmental pollutiondue to the use of noble metal catalyst, such as deleterious heavy metallic ions andharmful organic substance. Meanwhile, we apply heterogeneous catalysts for watermedium reactions. The solvents derived from petroleum, which currently remain thebasis of our chemical operations, one of the most large proportion of reagents, andalso one of the prominence sources of chemical pollution, are driving much of oursolution chemistry and separation issues and contain various health and environmentalconcerns. Discovering the new applications for ancient green solvent systems, water,could further decrease the environmental pollutions and lost and cost fromvolatilization and discharge of organic solvents.Since in water medium, solubility of organic reactants and catalyst is usually low,then, building appropriate catalyst, contacting two phase of water-oil, making thereaction to proceed smoothly, is the key issue in this paper. We selects the solventevaporation induced self-assembly technology, water hot method inducedself-assembly techniques, for the synthesis of nanostructured mesoporous porestructure and specific morphology of immobilized catalyst, and applied to watermedium organic synthetic reaction, the goal is to be able to develop high catalyticactivity and can be repeatedly used environmentally friendly catalyst; Based ondetailed characterizations, the correlation of catalytic performances to the structuralproperties was discussed. The detailed descriptions are listed as follows.1. Using ethanol solvent evaporation induced self-assembly synthesis technique(EISA), with EO-PO polyether Pluronic F127as the structure of guide agent, phenol and formaldehyde pre-polymers is formed under the condition of alkaline phenolicresin, copolycondensation proceeds under room temperature, formed two-dimensionalhexagonal ordered mesoporous structure of phenolic resin polymer catalyst carrier,via sulfonic acid group functionalization and ion exchange after grafting techniqueloading rare earth organometallic onto ordered mesoporous polymeric catalyst.Synthesized catalyst is used in carbon-carbon coupling probe reactionMukaiyama-Aldol reaction and exhibits excellent catalytic activity, this is due to thehigh specific surface area of mesoporous material, phenolic resin polymer stronghydrophobic pore wall, neat and orderly porous structure.2. Phenolic resin with low concentration of phenol and formaldehydepolymerization pre-polymers is synthesized, followed by EO-PO type polyetherPluronic F127as structure guide reagent, and the hydrothermal technique formed3-Dbody centered cubic ordered mesoporous pore structure of polymer nano spherecarrier, again through the sulfonic group functionalization and ion exchange aftergrafting technique of rare earth organometallic loaded type catalyst, on the one handovercome the defects of lower yields, longer preparation period, more difficult toenlarge synthesis of the EISA approach; Effective controling the length of the channelon the other hand, won the highly active surface catalytic materials and short diffusionchannel of small spherical catalyst, and used in C-glycosylation reaction, showedgood catalytic activity and repeated use of tolerance, after-grafting technique of rareearth metals at the same time guarantee the catalyst showed higher stability.3. With sulfonic group modification of ordered mesoporous phenolic resinpolymer carrier loading rare earth Lewis acid catalysts, on the one hand using sulfonicgroup functional carrier to provide large amounts of B acid and the other hand rareearth Lewis acid loading to form bifunctional catalyst, the catalyst used in glucosebiomass transfer reaction show good activity, stability.