Synthesis Of Indoles And Iron-catalyzed Polysubstituted Thiazoles

In the modern era,along with the rapid development of economic civilization,environmental pollution is also occurring all the time.As a chemical researcher,it is our responsibility to develop a new,efficient and pollution-free chemical reaction.In addition,indoles and thiazole also play an important role in medicine,materials,organic synthesis and other fields.Therefore,we mainly introduce two novel and pollution-free chemical reactions.One is the synthesis of indoles by the construction of a C-N bond without any metal catalyst and has no effect on the environment.Another reaction is to synthesize polysubstituted thiazoles through the construction of C-S bonds using anhydrous ferric chloride as a catalyst.As we all know,Iron is a cheap and easily available metal.Therefore,the development of these two synthetic methods is accord with the concept of green chemistry and provides a basis for the sustainable development of green chemistry.Part I: Metal-free synthesis of substituted indolesindoles,as an important intermediate in organic chemistry,it has extremely important significance and has been widely applied to various fields such as: materials science,drug synthesis,cosmetics industry.With the widespread of indoles derivatives,the synthesis methods of various indoles derivatives have also been continuously emerging with advantages and disadvantages.Here,our group has discovered a new method of indoles synthesis.we synthesized indoles derivatives by using 2-Vinylanilines as a substrate,PIFA and 1,4-benzoquinone as oxidants.This method is simple,easy to operate,and not only has good substrate compatibility,but also the reaction yield is high.The discovery of this method provides a more effective method for the synthesis of indoles.Part II: Iron catalyzed the synthesis of polysubstituted thiazolesPolysubstituted thiazoles are of great value in material science,medicinal chemistry,and organic chemistry.Therefore,simple and highly efficient methods for the synthesis of polysubstituted thiazoles have always been pursued by scientists.The synthesis of polysubstituted thiazoles is mainly on the construction of C-S bonds,In the past few decades,there have been many examples of synthesizing polysubstituted thiazoles by constructing C-S bonds.Here,we have discovered a new method for the synthesis of polysubstituted thiazoles,We use a rich,inexpensive and pollution-free elemental sulfur to react with enamines to producing polysubstituted thiazoles with anhydrous ferric chloride as a catalyst.This reaction mechanism involves electrophilic attack of elemental sulfur,imidization of enamines,nucleophilic cyclization,and oxidative aromatization.The reaction substrate has good compatibility and producing high yield.