Lewis Acid-Catalyzed,Copper(Ⅱ)-Mediated Synthesis Of Heteroaryl Thioethers

Heterocyclic compounds and its derivatives have important biological activity especially heterocyclic sulfide has very important applications in medicine and biology. However, the synthesis of this kind of compounds still has many difficulties. The recently reported synthesis method is only suitable to the synthesis of the benzene ring sulfide, but not to the synthesis of heterocyclic sulfide. In recent years, people are more interested in the synthesis of heterocyclic sulfide.We reported a case of the lewis acid and bialent copper ion catalyzed synthesis of heterocyclic sulfide without base, and discussed the impact of different Lewis acid catalysts on the reactivity.The article consists of two parts:(1) Optimizations of conditions:the catalysts, oxidants, solents, reaction temperature.and reaction time.The optimized reaction condition:the use of Lewis acids, AgCOOCF3,NiCl2,and FeF2as the catalysts, the amount of the catalysts is20mol%; the amount of the oxidant Cu(OAc)2is2equiv; under nitrogen conditions by using DMF as solvent; the highest yield can be98%.(2) Proposed a possible reaction mechanism:Summary from the experimental results and literatures, we proposed a possible reaction mechanism.