Study On Synthesis Of Sufur-containing Heterocyclic Compounds Using Inorganic Sulfides

2-Aminobenzothiazoles and thiophenes, are important intermediates and broadly found in material, pesticide medicine, pharmaceutical and other fields due to their high biological and physiological activities. Thus, development of general methods for the construction of these compounds is valuable.Recently, metal sulfides have been widely investigated for introducing sulfur atoms into organic molecules via C-S bond construction. Compared with thiols, they have obvious advantages such as low cost, low toxicity, relatively stability and easy operation. In this paper, general methods were developed for the formation of 2-aminobenzothiazoles and thiophenes using metal sulfides as sulfuration agents. The contents of this thesis are summarized as follow:Chapter one: Briefly introduction about the methods for synthesis of 2-aminobenzothiazoles and thiophenes are demonstrated, which a wide variety of sulfuration agents are utilized in synthetic transformations to afford organosulfur compounds.Chapter two: An efficient copper-catalyzed method for the synthesis of a variety of 2-aminobenzothiazoles via double C-S bond formation has been developed. The reaction proceeded from carbodiimide and sodium hydrosulfide via a tandem reaction in the presence of copper(II) trifluoromethanesulfonate to afford the corresponding 2-aminobenzothiazole derivatives in good to perfect yields. Two C-S bonds are formed via a copper-catalyzed traditional cross-coupling reaction. Finally, the desired products were obtained in an rearrangement and isomerization procedure.Chapter three: The transition-metal-free approach to synthesis of thiophenes was reported. A new, highly efficient procedure for the synthesis of thiophenes from 1, 3- butadiene and potassium sulfide has been developed. The desired products were obtained in an cycloaddition reaction and dehydrogenation procedure.