Study On The C-S Bond Formation For The Synthesis Of Sulfur Heterocyclics And Vinyl Thioethers

In recent years,the construction of C-S bond has been the focus of chemical researchers.As an important synthetic tool,it has been widely used in the synthesis of heterocyclic compounds.Heterocyclic chemistry is also one of the most concerned fields in organic chemistry.Among them,S,N-containing heterocyclic compounds occupy very important positions in heterocyclic compounds.Therefore,in this thesis,we explored the thiocyclization reaction of propynamide derivatives and the defluorinative sulfuration reaction of fluorinated compounds.The main content of this thesis consists of four parts:(1)The background of the synthesis of thio-nitrogen heterocyclic compounds and the research progress of C-F bond activation are briefly summarized in recent years.(2)A copper-catalyzed thiocyclization reaction of propynamide with sodium sulfide has been developed to synthesize isothiazol-3-one.This reaction avoids the shortcomings of the multi-step reaction in traditional methods and the environmental pollution of by-products,which presented a new pathway for the efficient preparation of isothiazol-3one derivatives.(3)1,3-thiazin-4-one and thiazolidine-4-one derivatives were synthesized by the thiocyclization of propynamides under transition-metal and base-free conditions.The reaction material is easy to obtain and the condition is mild,and has excellent functional group compatibility(4)A copper-catalyzed strategy for the selective synthesis of fluorovinyl sulfide from defluorosulfurization of trifluoropropionamide was developed.The defluorination of C(sp~3)-F bond was achieved to obtain a monofluorovinyl sulfide product.The reaction yield was moderate to excellent,and the good functional group compatibility was observed,which provides a new strategy for the construction of C-S bond.