A nitrogen-containing ligand hemicellulose-palladium catalyst and its preparation method and application

Abstract

The invention belongs to the technical field of catalysis, and discloses a nitrogenous ligand hemicelluloses-palladium catalyst as well as a preparation method and application thereof. The preparation method of the catalyst comprises the following steps of: adding ethylenediamine modified hemicelluloses or phenanthroline modified hemicelluloses and palladium salt to a solvent, performing a reaction for 4-24 hours at the temperature of 20-60 DEG C to obtain a reaction product, filtering the reaction product, washing the filtered reaction product, and drying the washed reaction product so as to obtain an ethylenediamine modified hemicelluloses-palladium catalyst or a phenanthroline modified hemicelluloses-palladium catalyst. The application process of the catalyst in a Suzuki coupled reaction comprises the following steps of: adding the ethylenediamine modified hemicelluloses-palladium catalyst or the phenanthroline modified hemicelluloses-palladium catalyst, halogeno benzene, arylboronic acid and alkali to a solvent, performing a reaction for 1-5 hours at room temperature to obtain new reaction products, filtering the new reaction products so as to remove the catalyst, performing reduced pressure distillation on filtrate so as to remove the solvent, and performing column chromatography purification so as to obtain a catalytic synthesis product. The catalyst disclosed by the invention has the advantages of being good in catalytic effect, convenient to separate and low in cost, and has favorable application prospects.

Description

technical field [0001] The invention belongs to the technical field of catalysis, and in particular relates to a nitrogen-containing ligand hemicellulose-palladium catalyst and a preparation method and application thereof. Background technique [0002] Since Suzuki et al. reported in 1981 that palladium-catalyzed organoboron compounds and halogenated hydrocarbons could undergo coupling reactions to prepare unsymmetrical biaryls under very mild conditions, the formation of Aryl-Aryl bonds has opened up a new field. Suzuki-Miyaura cross-coupling reaction is currently the most widely used method for the preparation of biaryl and its derivatives. Due to its strong substrate adaptability and functional group tolerance, it is often used in the synthesis of polyenes, styrene and biphenyl Derivatives of the reaction are applied in the synthesis of many natural products and organic materials. This reaction has a wide range of applications in pesticides, medicines, polymers, dyes and ...

AI Technical Summary

Problems solved by technology

Among them, polymer-supported metal catalysts have become a research hotspot due to their high catalytic activity and stereoselectivity, good stability and reusability, but currently such polymer-supported palladium catalysts are mostly made of synthetic polymers. carrier, the preparation process is cumbersome and the cost is high

The literature also reported the use of inorganic substances (such as carbon, metal oxides, zeolites, etc.) to support palladium to catalyze the Suzuki reaction, and achieved a good catalytic effect, but it still has the disadvantages of complicated preparation methods and high costs.

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