| Due to wide-ranging applications in chemical,pharmaceutical industries and as intermediates in organic synthesis,sulfides have emerged as crucial class of organic compounds.Although transition-metal catalyzed carbon-heteroatom cross-coupling reactions have made a great contribution to prepare such sulfides,the efficient formation of the C-S bond is still a most imperative aspect of organic chemistry.Through inspecting,analyzing and summarizing extensive literature,this paper was carried mainly out from the following three aspects:Firstly,the reaction of the thiolazole compounds with aryl iodide resulted in a series of aryl thioether compounds under microwave irradiation.It showed that the yield of target product was up to 79 to 88%.The target compounds were characterized by 1H NMR,13C NMR and HRMS.By discussing different reaction conditions,the optimum reaction conditions were as follows:microwave power 30 W,microwave irradiation for 15 min,CuI(10%mol)as the catalyst,DMF as solvent.At the same time,the advantages of microwave radiation reaction were tracked by HPLC analysis,and the reaction of 2-mercapto-benzoxazole,2-mercapto-benzothiazole,5-methoxy-2-Mercapto-benzimidazole and 2-mercaptobenzimidazole with 1,4-iodobenzene were studied in detail.Secondly,the reaction of benzoxazole compounds with thiophenol were carried out under microwave irradiation to obtain a series of benzene-heterocyclic aromatic sulfide in yield of 82%.The target compounds were characterized by 1H NMR,13C NMR and HRMS.By discussing different reaction conditions,the optimum reaction conditions were as follows:microwave power 35 W,C2H5ONa as base,reaction time for 25 min,Cul(12%mol)as the catalyst,DMF as solvent.By measuring the influence of the microwave radiation and conventional heating conditions on yield,we can be seen that microwave irradiation greatly reduces the response time and improves the yield.It provides a kind of new ways for synthesis of benzene-heterocyclic aromatic sulfide.Thirdly,aryl sulfide was obtained in higher yield in the absence of alkali and metal by the reaction of diaryliodonium triflate with aromatic mercapto compounds.The target compounds were characterized by 1H NMR,13C NMR and HRMS.By discussing different reaction conditions,the optimum reaction conditions were as follows:n(diaryliodonium triflate):n(aromatic mercapto compound)=1.2,DMF as solvent,the reaction temperature 130℃and the reaction time for 24 h.In addition,possible mechanism of the reaction was discussed in detail.This simple and selective method for synthesis of aromatic sulfide provides experimental data and theoretical basis for industrial synthesis,pharmaceutical intermediates and special heterocyclic. |
