Preparation Of Two Supported Catalysts Efficiently Catalyze C-C Coupling Reaction In Water

The C-C coupling reaction is widely used in organic reactions.It can transform molecules into complex compounds through simple reactions,while transition metal catalyzed C-C coupling reactions are widely used in the synthesis of complex compounds.As a clean energy source,visible light has been widely used in the synthesis of small organic molecules by its induction-catalyzed redox reaction strategy,and it has successfully constructed a C-C coupling reaction.With the requirements for green chemistry,how to find a highly efficient and clean green catalytic synthesis strategy has becomes crucial.Our solution is to load the catalyst on a new type of material to achieve catalyst recycling.In this paper,two kinds of supported catalysts have been developed that can achieve the C-C coupling reaction in the aqueous phase.The first is to use the hydrophobic polydimethylsiloxane(PDMS)sponge material as a carrier,modified by surface modification technology,and then combined with palladium acetate through the coordination of chemical bonds,and finally reduced under the action of sodium citrate into palladium nanoparticles.Qualitative analysis of the sponge palladium material by SEM and EDS can prove that the palladium nanoparticles were successfully loaded on the sponge material,and the catalyst loading was obtained by ICP quantitative analysis.In terms of catalytic performance,the palladium sponge catalyst in the aqueous phase in the Suzuki-Miyaura reaction and hydrogenation reduction reaction has achieved a high yield and is suitable for a wide range of substrates.Through the easy-to-construct continuous flow reactor,PDMS palladium sponge promotes the reaction and can successfully scale up.The second catalyst is an organic-inorganic composite material formed by self-assembly of anionic dye rose red(RB)visible light catalyst,Fe₃O₄nanoparticles,and positively charged aluminum magnesium hydrotalcite(LDH).Through the characterization of the material and the analysis of the reaction products,the catalytic performance of this organic-inorganic composite material is the same as that of the free rose red visible light catalyst,and this photocatalyst can not only catalyze the CDC reaction in the aqueous phase under green light conditions,but also Magnetism makes it easier and faster to recycle.Both catalysts have the following advantages:1.Separation and purification is more convenient,there is no need to use traditional centrifugation or filtration operations,repeated use will not significantly reduce its catalytic efficiency.2.The preparation of the catalyst is simple and direct,which is convenient for large-scale promotion.3.The reaction conditions are mild and the solvents(ethanol and water)are green.In summary,this paper introduces two catalysts that effectively catalyze the coupling reaction of C-C bonds.Surface modification techniques are used to modify PDMS sponges,which can successfully load palladium nanoparticles.As well as loading rosy red dye on LDH in the form of ionic bonds,it can catalyze CDC reaction in green solvent under the excitation of visible light.Therefore,both PDMS sponge materials and positively charged aluminum-magnesium hydrotalcite(LDH)can be used as carriers to support various catalysts to react in the aqueous phase,and have good application prospects.