Preparation method for modified palladium-carbon catalyst for Suzuki coupling reaction

Abstract

The invention discloses a preparation method for modified palladium-carbon catalyst for Suzuki coupling reaction. The catalyst is composed of active carbon, and palladium and nickel loaded on the active carbon, wherein the mass percent of the palladium is 5-10%, and the mass percent of the nickel is 0.5-3%. The preparation method for the modified palladium-carbon catalyst for the Suzuki coupling reaction includes steps that 1, preparing nano-nickel sol; 2, preparing active carbon carrier; 3, preparing nickel-containing size; 4, preparing palladium-containing solution; 5, adding the palladium-containing solution to the nickel-containing size, preserving the heat, dipping and filtering to obtain a piece of filter cake; 6, performing reduction treatment, and washing to obtain the modified palladium-carbon catalyst. The modified palladium-carbon catalyst prepared by the method can be used for the Suzuki coupling reaction, and the modified palladium-carbon catalyst has advantages of high reaction activity, high selectivity, good stability and the like; the catalyst is easy to be separated from the product, the catalyst preparation technique is simple, the catalyst can be used repeatedly, the precious metal-palladium is easy to recycle, the pollution and energy consumption are reduced, and the economical benefit and environment significance are important.

Description

technical field [0001] The invention belongs to the technical field of preparation of supported noble metal catalysts, and in particular relates to a preparation method of a modified palladium carbon catalyst for Suzuki coupling reaction. Background technique [0002] Since Miyaura et al. reported in 1979 that under the catalysis of palladium, the coupling reaction of organoboron compounds and halogenated hydrocarbons under mild conditions to prepare asymmetric biaryls, the Suzuki coupling reaction has formed a new era in the selective construction of carbon-carbon bonds. a new field of research. Carbon-carbon bond coupling can transform simple molecules into complex ones, and plays an extremely important role in chemical synthesis. This key step is included in the synthesis of many organic chemicals such as drugs, dyes and pesticides. In recent years, it has been a research hotspot in catalytic chemistry and organic chemistry. The research and development of Suzuki couplin...

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Problems solved by technology

[0003] For a long time, the catalyst of the Suzuki coupling reaction is mainly a homogeneous palladium catalyst. Palladium usually forms a homogeneous catalyst with an organic ligand (such as a palladium-phosphine complex, etc.), and the catalyst activity is often high, the selectivity is good, and the reaction conditions are relatively Mild, but there are problems such as high price: ①Most phosphine ligands are sensitive to air and moisture, and need to be in an inert gas atmosphere to effectively catalyze the reaction; ②The homogeneous catalyst is difficult to separate from the reaction mixture, and cannot be recycled and reused. ③ Trace metal residues will contaminate the product, which is a fatal shortcoming especially for pharmaceuticals and some fine chemicals with high requirements

[0006] At present, compared with homogeneous palladium catalysts, Pd / C catalysts still have problems such as low activity and poor catalytic effect on chlorinated aromatics, which need to be improved.

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