Selective Synthesis Of Sulfur-and Nitrogen-Containing Heterocycles Under The Participation Of Non-Precious Metal Catalysts

Sulfur-containing heterocycles and polynitrogen heterocycles are important components of heterocyclic compounds,occupying an increasingly important position in medical,pharmaceutical,dye and functional materials.Focusing on the theme of"Study on the Selective Synthesis of Sulfur-and Nitrogen-Containing Heterocycles under the Participation of Non-precious Metal Catalysts",we started with simple and easily available raw materials such as elemental sulfur or aromatic aldehydes,generating sulfur-and nitrogen-containing heterocycles with MCRs in one pot.The paper details are exhibited as follows:1.A three-component one-pot construction of 2-aryl-substituted benzothiazole derivatives using elemental sulfur as the sulfur source and catalyzed by none-precious metals with nitroaromatics and benzyl alcohol compounds was described.Under iron catalysis,in situ hydrogen reduction,C-N condensation,and C-S bond formation were achieved in one pot.A variety of heterocyclic nitroarenes can generate heterocyclic thiazole derivatives with high selectivity under mild conditions,providing an alternative route for 2-substituted benzothiazoles.2.A novel method for the efficient synthesis of symmetricalπ-A-π-type thienopyrrole diketo derivatives（TPDs）by a three-molecule four-component one-pot method has been developed.This is the first pioneering strategy for the direct synthesis of TPD frameworks in one pot.The reaction started from the simplest starting material,benzaldehyde,cheap and readily available NMP and elemental sulfur,and realized multiple C（sp³）-H activation through oxidation and aldol condensation.3.A method for one-pot synthesis ofπ-A-πconjugated TPD derivatives from various benzyl carbon sources,lactams and elemental sulfur was developed.A variety of benzyl compounds could be used as C1 sources,and benzyl alcohol,phenylacetic acid,benzylamine,benzyl chloride,benzyl bromide,benzyl ether,etc.could all complete this transformation.The reaction did not require transition metal catalysis,nor additional organoboron reagents or toxic organotin reagents,and the conditions were simple and mild,providing an alternative strategy for the synthesis of TPD.4.A one-molecule,four-component condensation reaction strategy was developed,in which nitrobenzaldehyde was used as the nitrogen source and the polyazacyclic tricyclic quinazoline was successfully generated in one pot under mild conditions with the promotion of elemental sulfur.The reaction was efficient and highly atomic economic.Multiple steps such as redox condensation and cyclization could be realized in one pot.Besides,tricyclic quinazoline was also used as a photocatalyst to realize the photocatalytic reduction of CO₂,generating CH₄ and CO with high yields,which provided an alternative strategy for the photocatalytic reduction of CO₂ by organic nitrogen heterocycle.5.A three-component assembly method was developed to synthesize multivariate nitrogen heterocycles.A single N2-alkylated product was synthesized by the combination of indoles,4-phenyl-1-toluene sulfonyl-1H-1,2,3-triazole derivatives,cyclohexanone or aromatic aldehydes under one-pot conditions.The reaction conditions were simple and mild,with the products possessing chiral or latent chiral center.