Study On The C-N Coupling Reaction Of N-tosylhydrazones And Diaryliodonium Salts

The sulfonamides exhibit a wide range of biological activities.They have antibacterial,anti-inflammatory,anticancer,antitumor and anticonvulsant and HIV protease inhibitory activities.The synthesis of sulfonamide compounds is great significance in organic synthesis.The N-arylated products of tolylhydrazone have some applications.For example,they can be used as inhibitors to inhibit the expression of metal-?-lactamase in Escherichia coli,and have a very good antibacterial effect.In order to achieve valuable C-N coupling reactions under mild,green,environmentally friendly conditions,this dissertation beginned this study.In view of the value of sulfonamide compounds and N-arylation products of sulfonylhydrazone and the applicability of C-N coupling reaction,it was proposed to use N-tosylhydrazones as raw material and synthesize N-aryl tosylhydrazones by C-N coupling reaction.N-Tosylhydrazones are a class of highly reactive,labile compounds that can be easily converted to a reaction intermediate--the diazo compound that can react with many types of substrates.The diaryl iodonium salts was selected as the substrates involved in the reaction with tosylhydrazine.It is a stable,low toxicity,mild arylation agent.It can activate the C-H bond to coupling reactions with the arylation of carbon,nitrogen,oxygen,sulfur and phosphorus,etc.The preparation of diaryliodonium salt is simple,high yield.Since the starting material used is a benzene series,diaryliodonium salts containing various substituents can be prepared.This also expands the scope of the investigation of the substrate for the study.In this paper,benzaldehyde N-tosylhydrazones were synthesized from the common benzaldehyde,and diphenyliodonium salts was synthesized from iodine monomer and benzene.The C-N coupling reaction between diphenyliodonium salt and benzaldehyde N-tosylhydrazones was explored.N'-arylmethylidene-N-aryl N-tosylhydrazones was obtained as the product.In order to determine the optimal reaction conditions,catalysts,bases,temperatures,solvents,ratios of reactants,and reaction time were screened.Based on the results,the optimal reaction conditions for the reaction were determined: CuI as a catalyst,Cs2CO3 as a base,1,4-dioxane is a solvent,and the ratio of N-tosylhydrazones and diaryliodonium salt is 1:1.5,and the reaction is carried out at a temperature of 60? for 24 h under the protection of argon gas.The suitability of N-tosylhydrazones and aryliodonium salts was investigated based on the optimized conditions.The reaction of various N-tosylhydrazones and diphenyliodonium salt trifluoromethanesulfonate were investigated;then the reaction of various diaryliodonium salts with benzaldehyde to N-tosylhydrazones were investigated.According to the results of the reaction,it can be confirmed that corresponding target products can be obtained,and the reaction has good applicability.In addition,the research on the substitutability of diaryliodionium salt showed that it have an irreplaceable role in the reaction.In summary,this paper explores the C-N coupling reaction of tosylhydrazones and diaryliodonium salts under mild conditions.The reaction proceeds well with a cheap,readily available catalytic system with cuprous iodide and without ligand addition.The synthesized products were characterized by using proton nuclear magnetic resonance spectroscopy,carbon-13 nuclear magnetic resonance spectroscopy,infrared spectroscopy,high resolution mass spectrometry,and single crystal diffraction.