Access To Thiazoles Via[3+2]Cycloaddition Of 1,2,3-Thiadiazoles With Isonitriles

Sulfur heterocyclic compounds are a kind of important organic molecules,which play an important role in our daily life.These compounds exist in natural products,and are widely used in materials science,pharmaceutical chemistry and pesticide fields,demonstrating the importance of these compounds.Therefore,the efficient synthesis of sulfur-containing heterocyclic compounds with various structures,such as thiazole derivatives,is of great significance for improving human production and living standards and promoting social development.In recent years,different reactivities of 1,2,3-thiadiazole had been gradually reported.In these reports,1,2,3-thiadiazole could be used as a precursor of high active intermediate α-thiavinyl carbene,and was mainly used to synthesize a variety of sulfur-containing or nitrogen-containing heterocyclic compounds.However,there were few reports based on thioketene reactivity.In this paper,the cycloaddition of thioketenes with isonitriles to construct thiazole derivatives with various structures was studied.This paper was divided into the following two parts:In the first part: the common synthesis methods of thiazole were summarized,such as the classical Hantzsch synthesis method and its various improved methods.At the same time,the applications of thiazole in medicine,materials,pesticides and other fields were also introduced in detail.In the second part: firstly,the current synthesis methods of 1,2,3-thiadiazoles and its application in the synthesis of heterocyclic compounds were introduced.Secondly,based on the importance of thiazole and its derivatives in synthesis,our group reported that 4,5-disubstituted thiazole derivatives were constructed by [3+2] cycloaddition of1,2,3-thiadiazoles with isonitriles under the presence of base.The reaction was simple and had good functional group compatibility without expensive metal catalysis.The experimental results showed that the selective cyclization of sulfur leaded to the formation of thiazoles.This reaction provided a new idea for the preparation of sulfur-containing heterocyclic compounds through the cyclization of thioketene with dipoles or their equivalents.At the same time,the active compounds,which showed good inhibitory effect on E.coli type I methylthio aminopeptidase(Ec Met AP1)and yeast type I methylthio aminopeptidase(Sc Met AP1),synthesized by this reaction.Finally,this chapter maked a summary and putted forward the significance of this topic selection.In this paper,the [3+2] cycloaddition of 1,2,3-thiadiazoles,that were the precursor of thioketene,with isonitrile were studied in detail.And the application of the resulting thiazole derivatives in the biological field was further studied,which had certain reference value for studying the reactivity of thioketene.