A method for synthesizing n-aryl hydrazones from halogenated aromatic hydrocarbons and hydrazone compounds under visible light catalysis

Abstract

The invention discloses a method for catalyzing aryl halide and a hydrazone compound to synthesize N-aromatic hydrazone through visible light. According to the method, synthesis of N-aromatic hydrazine is achieved by using a multi-substituted BODIPY organic compound as a photocatalyst for concerted catalysis with nickel. Compared with an existing synthesis method, C-N coupled reaction is achieved by using transition metal nickel and an organic photosensitizer in the absence of a ligand. The catalyst used for the method is cheap, available, high in catalytic efficiency, mild in reaction condition, friendly to environment and high in product yield; and the application scope of a substrate is wide.

Description

technical field [0001] The invention relates to a method for efficiently catalyzing halogenated aromatic hydrocarbons and benzophenone hydrazone compounds to synthesize N-arylhydrazones by using multi-substituted BODIPY organic photocatalysts and transition metal nickel catalysts under visible light irradiation conditions. Background technique [0002] Most nitrogen-containing heterocyclic compounds are physiologically active and are important structural fragments of some natural products, functional materials and drug molecules, while aryl hydrazones and their derivatives play an important role in the synthesis of nitrogen-containing heterocyclic compounds. The method for synthesizing N-aryl hydrazone can be divided into two major classes at present, and the first kind is the method for metal-free catalysis, mainly by acid-base catalysis (Resnicket al., J.Org.Chem., 1965,30,2832-2834; Bigdeli et al., J.Chem.Res.1999,9,570-571) and microwave catalysis (Silvestri et al., Acs ...

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Problems solved by technology

The method for synthesizing N-aryl hydrazone can be divided into two major classes at present, and the first kind is the method for metal-free catalysis, mainly by acid-base catalysis (Resnicket al., J.Org.Chem., 1965,30,2832-2834; Bigdeli et al., J.Chem.Res.1999,9,570-571) and microwave catalysis (Silvestri et al., Acs Combinatorial Science, 2011,13,2-6), although the reaction operation is simple but the tolerance of functional groups is not Well, the substrate is not widely applicable

The second kind is the method of transition metal catalysis, mainly contains palladium catalysis (Hartwig et al., Angew.Chem.Int.Ed., 1998,37,2090-2093; C.Mauger, G.Mignani.Syn.Commun., 2006,36,1123-1129.), copper catalysis (Buchwald et al., J.Am.Chem.Soc.2001,123,7727-7729) and nickel catalysis (Yang et al., RSC Adv.,2014,4 , 3364-3367.) Three systems, although palladium catalysis has a better reaction effect but palladium is relatively expensive, copper catalysis has higher requirements for substrates and only highly active iodoaromatics can react. The currently reported nickel catalysis method is practical Poor performance, cannot react with substrates containing carbonyl and cyano groups, and transition metal catalysis requires ligand regulation, and ligands are usually expensive

Traditional photocatalysts are generally complexes of ruthenium and iridium. This type of catalyst has strong absorption under visible light, is stable and has a long life cycle, but it uses noble metals and the synthesis cost is high.

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