Copper And Iron Promote Hydrocarbon Sulfonium Replace The Synthesis Of Heterocyclic Compounds

Carbon-sulfur bond is displayed in a wide range of natural products and organic molecules. Many sulfenyl-substituted heterocycles exhibit significant biological activities. Therefore, development of new efficient and environmental friendly methods for the synthesis of this class of compounds from readily available starting materials using cheap catalysts is an important goal of organic synthesis. This dissertation focuses on the inexpensive cuprous (cupric) or ferric salts promoted electrophilic cyclization reactions of disulfides with functional alkynes and electrophilic substitution reaction with azaheterocycles, as well as coupling/cyclization/(electrophilic substitution) reaction of disulfides with functional gem-dibromoalkenes. The dissertation is divided into six parts.1. CuI-catalyzed electrophilic addition/cyclization reaction of2-alkynylanilines with disulfides has been established, which provides a convenient and efficient procedure for the synthesis of3-sulfenylindoles. Moreover, the method proved to be efficient for construction of complex products bearing two attached3-sulfenylindole rings in one-pot process. The present experimental results indicate that both disulfide and the copper catalyst can be reproduced from intermediate phenylthiolate copper under the present conditions in the presence of air.2. CuI catalvzed efficient and environmentally friendly electrophilic substitution reaction of azaheterocycles with disulfides has been developed for the synthesis of various sulfenyl-substituted azaheterocycles. Morever, the electronic effect of substituents and its impact on the reaction were investigated in detail.3. FeCl3-promoted electrophilic addition/cyclization reaction of2-alkynylbenzoates with disulfides, which provides a facile and highly regioselective synthetic approach to4-sulfenylisocoumarins. The present procedure is also an efficient approach to thieno-and indol-fused chalcogenylpyrone frameworks. Furthermore, bicyclization product,(E)-3-(2-phenyl-3-(phenyIsulfenyl)inden-1-ylidene)isobenzofuranone, could be achieved via a domino reaction sequence of diynylbenzoate with disulfide. These results disclosed the extraordinary effect of substrates for the6-endo-dig and5-exo-dig annulation. Morever, primary research disclose that3-sulfenylfuran can be synthesized by electrophilic addition/cyclization reaction of2-alkynyloxirane with disulfide.4. CuCl2promoted sulfoamination/cyclization of N,N-dimethyl-2-alkynylanilines with disulfides has been developed for the synthesis of3-sulfenylindoles. It is found that the haloamination/cyclization products can be selectively obtained without the presence of disulfides in the reaction procedure. In addition, Suzuki-coupling reaction of3-chloroindoles with phenyl boronic acids is carried out.5. An alternative route to sulfenylindoles is developed by Cul-catalyzed electrophilic substitution of disulfldes with indoles generated in situ by Pd(OAc)2-catalyzed coupling/cyclization of gem-dibromovinylanilines with phenyl boronic acids.6. Cul-catalyzed coupling/cyclization reaction of gem-dibromovinylphenols with disulfides, which introduction of a sulfenyl functionality at2-position in the formation of benzofurans for the first time. This method provides an efficient and convenient procedure for the formation of2-sulfenylbenzofurans.