Method for preparing alkylation aromatic hydrocarbons

Abstract

The invention discloses a method for preparing alkylation aromatic hydrocarbons. The method includes that an iron (III) complex whose molecular formula is Fe (PPh3) 2Cl3 is taken as a one-component catalyst, and in the presence of magnesium, synthesis of the alkylation aromatic hydrocarbons is performed by cross-coupling reaction of aryl halide and beta-H containing primary and secondary alkyl halogenated hydrocarbons. The method is mild in a reaction condition, and sensitive Grignard reagents and multicomponent catalysts can be prevented from being used; the method has high catalytic activity on alkyl bromine generation hydrocarbons and alkyl chlorinated hydrocarbons, and simple column chromatography is performed after the reaction is completed to obtain final products; raw materials used in the reaction are rich in source and conform to requirements and direction of contemporary development of green chemistry, and accordingly having industrial application values.

Description

technical field [0001] The invention belongs to the technical field of preparation of organic compounds, and in particular relates to a catalytic preparation method of alkyl-substituted aromatic hydrocarbons. Background technique [0002] Alkyl substituted aromatics are useful as intermediates in the preparation of polymers and pharmaceuticals. For example, the corresponding alkyl-substituted aromatic hydrocarbons are peroxidized, and then the corresponding phenolic products are obtained through acidolysis and separation. Compared with the traditional synthesis process of phenolic substances, this route has the advantages of low pollution, high atom utilization rate, and convenient continuous production, and is an ideal green synthesis route. [0003] Cross-coupling reactions catalyzed by transition metal complexes, such as Kumada cross-coupling reactions, are one of the most important methods for forming carbon-carbon bonds and have become a class of classic reactions in o...

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Problems solved by technology

This reaction successfully avoids the direct use of Grignard reagents by generating Grignard reagents in situ during the reaction, which is a great improvement over the traditional Kumada cross-coupling reaction; however, the above-mentioned reports have obvious drawbacks, mainly including : (1) Anhydrous ferric chloride is very easy to deliquescence, inconvenient to operate, and the purity of anhydrous ferric chloride is often mixed with a very small amount of other metals (such as copper) depending on its commercial source, resulting in unstable catalytic performance , (2) Excessive nitrogen-containing ligands need to be used, and the feeding rate is too slow. (3) The reaction substrate is mainly limited to primary and secondary alkyl brominated hydrocarbons containing β-H. Compared with alkyl brominated hydrocarbons, Alkyl chlorinated hydrocarbons have obvious price advantages and diversity, and have more commercial application prospects. However, the catalytic activity of the above-mentioned developed iron catalysts for the cross-coupling reactions involving β-H-containing alkyl chlorinated hydrocarbons needs to be improved. , in the coupling reaction process, alkyl chlorinated hydrocarbons are prone to side reactions such as dehalogenation, and the yield of the target product is generally low

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