Quasi homogeneous magnetic nano-particle supported palladium catalyst and preparation method

Abstract

The invention relates to a magnetic nanoparticle-loaded palladium catalyst and a preparation method thereof. The catalyst carrier adopts silica gel with a shell-core structure to wrap ferroferric oxide magnetic nanoparticles, and has a high specific surface area, excellent dispersion and mechanical properties. ; The catalyst has superparamagnetism at room temperature and is easily magnetized under the action of an external magnetic field. The magnetism disappears after the magnetic field is removed, so it is easy to achieve the purpose of rapid separation, recovery and recycling of the palladium catalyst; the surface of the nanocarrier is processed through "click chemistry" "The strategy covalently bonds the Sievert's base ligand to load the organic ligand firmly and effectively, and the longer carbon chain in the middle keeps the Sievert's base ligand away from the carrier, allowing it to better coordinate with the metal, thus The effect of homogeneous catalysis is achieved; the catalyst is suitable for the Suzuki reaction of halogenated benzene and arylboronic acid. Under mild reaction conditions, a higher yield can be obtained and the catalyst can be reused multiple times with basically unchanged activity.

Description

technical field [0001] The invention relates to a palladium catalyst supported by magnetic nanoparticles and a preparation method thereof, in particular to a palladium catalyst supported by ferric iron tetroxide magnetic nanoparticles coated with silica gel surface-modified by "click chemistry" and a preparation method thereof. Background technique [0002] Palladium-catalyzed C-C coupling reactions such as Suzuki, Heck, and Sonogashira reactions are important methods for forming C-C bonds in pharmaceutical synthetic chemistry. Homogeneous catalysts such as palladium chloride or palladium acetate can effectively catalyze the above C-C coupling reaction, but these homogeneous palladium catalysts are difficult to separate and recover from the reaction system. In addition, palladium black is easily formed during the reaction process, which not only significantly reduces the activity of the catalyst, but also contaminates the reaction product, which limits its practical applicat...

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Problems solved by technology

Due to the huge specific surface area of ​​the nano-size effect, the influence of mass transfer resistance can be greatly reduced, and the activity is well maintained. However, because the nano-carrier is too small, it is still difficult to separate the supported catalyst from the reaction system.

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