Study On The Synthesis Reaction Of Diaryl Sulfide

Sulfide in particular diaryl sulfide is an important structural elements in organic synthesis,widely used in pharmaceutical and agricultural chemicals,its synthesis and application have been paid more and more attention in recent years.Transition metal catalyzed aromatic acid decarboxylation and coupling with nucleophiles or reacting with electric reagent provides a new way of constructing carbon carbon,carbon heteroatom bond;It has atom economy and reaction efficiency when constructing the chemical bond based on the C-H activation strategy.This article studies two methods to construct the C-S key,one is copper catalysis aromatic acid decarboxylation and coupling with sulfur compounds;another is nitrogen heterocyclic compounds reacting with aryl isothiocyanates via C-H activation promoted by the base.1.The coupling reaction of aryl acid and sodium thiocyanate were carry out in the presence of Cu?/Ag system.By optimizing we get the optimal reaction conditions:aromatic acid potassium salt 0.3 mmol,sodium thiocyanate 3.0 equiv,20 mol%CuCl₂,25 mol%Phen.,130 mol%Ag₂CO₃,0.2 g 4 A MS in DMF:xylene?1:1?1.5 mL at 150 C,and obtain 4 examples of symmetric diaryl sulfides at 64%-92%yields.Then the sulfur source has been extended to aryl thiocyanates,through the simple optimization we get the better conditions:aromatic acid potassium salt 0.3 mmol,aryl thiocyanate 3.0 equiv,20 mol%CuCl₂,25 mol%Phen.,130 mol%Ag₂CO₃,0.2 g 4 A MS in DMF 1.5 mL at 120?,and obtain 22 examples of unsymmetric diaryl sulfides at 53%-92%yields.2.The coupling reaction of nitrogen heterocyclic compounds and aryl thiocyanate were carry out in the presence of base system.By optimizing we get the optimal reaction conditions:nitrogen heterocyclic?indole,benzothiazole,oxadiazole?0.3 mmol,aryl thiocyanates 4 equiv,the base is BuOK or Cs2CO3?5 equiv?in dioxane?1.5 mL?at 140?,and get 13 examples of aryl heteroaryl sulfides at 71-93%yields.When the nitrogen containing heterocyclic is imidazole compounds,we should add 20 mol%CuCl₂ 130 mol%Ag₂CO₃,and get 3 examples of 2-aryl sulfenyl imidazole compounds at 63-78%yields.