The Research On The Synthesis Of The Derivatives Of Benzothiophene And Quinoline

Sulfur-containing heterocyclic compounds and nitrogen-containing heterocyclic compounds play an important role in fine chemistry in terms of type,quantity,and uses.Benzoheterocyclic compounds have been widely used in chemistry,biology,pharmacy,agronomy and materials science due to their special conjugate structures and unique biological activities,which has attracted wide attention of chemists.Benzothiophene derivatives are a kind of sulfur-containing benzoheterocyclic compounds,which are widely used in the fields of pesticides,pharmaceuticals,dyes and functional materials.To date,lots of elegant methods have been access to the synthesis of these substituted benzothiophene cores,including intramolecular cyclizations ofα-arylth-ioketones,o-alkynyl（alkenyl）benzenthiols,and arylthioethers,and direct arylation of the benzothio-phene moiety and other methods.Although great progress has been achieved by using these strategies,prefunctionalized thiophenols have to be synthesized for the transformations,which limited their pervasive applications in organic synthesis.Therefore,the synthesis of substituted benzothiophenes by simple and available thiophenol is an effective and practical method.Quinoline（also known as benzodiazepines）derivatives are very important nitrogen-containing benzoheterocyclic compounds,Because of its good pharmacological,biological and optical activity,it is widely used in the fields of medicine,pesticides and materials.The classical route to quinoline ring system proceeded from the condensation of substituted aryl anilines withβ-diketones orβ-ketoesters under strongly acidic conditions.However,this procedure involves harsh reaction conditions,poor functional group tolerance,and difficulty in controlling regioselectivity,which limited their application in organic synthesis.Therefore,it is very important to developing simple,efficient and green method to construct quinoline skeleton derivatives.The main contents of this article are as follows:（1）The synthesis of 5-methylbenzothiophene-2,3-dicarboxylate derivatives by visible light-induced tandem addition/cyclization of thiophenol and dimethyl butynediate with Mes-Acr-Me⁺as photocatalyst,PhCOOH as additive and CHCl₃ as solvent under room temperature stirring in argon atmosphere was studied.（2）The synthesis of ethyl 4-benzoyl-2-phenylquinoline-3-carboxylate derivatives by visible light-induced intramolecular oxidation cyclization of aromatic enamines with Mes-Acr-Me⁺as photocatalyst,CuCl₂ as catalyst,TBHP as oxidant,Phen as ligand,DMF as solvent under room temperature stirring in oxygen atmosphere was studied.（3）The synthesis of dimethyl 4-benzoylquinoline-2,3-dicarboxylate derivatives by visible light-induced intermolecular addition/oxidative cyclization of O-alkyne aniline and dimethyl butynediate with Ru（bpy）₃Cl₂ as photocatalyst,CuCl as catalyst,DMF as solvent under room temperature stirring in oxygen atmosphere was studied.（4）The synthesis of dimethyl quinoline-2,3-dicarboxylate derivatives by visible light-induced intermolecular addition/oxidative cyclization of O-alkene aniline and dimethyl butynediate with Ru（bpy）₃Cl₂ as photocatalyst,PdCl₂ and CuCl₂ as catalyst,PivOH as additive,Phen as ligand,DMF as solvent under room temperature stirring in oxygen atmosphere was studied.（5）A new and efficient synthetic approach for the N-arylation of8-aminoquinoline amides with diaryliodonium salts has been developed,this method uses cheap and available Cu（OAc）₂·H₂O as catalyst without additional ligands and bases through chelation assisted selective C-N cross-coupling reaction gives the desired N-arylated 8-aminoquinolineamide derivatives.