Synthesis Of 3-Pentafluorophenyl-2-Arylbenzoheterocycle And S-Pentafluorophenyl Sulfonium Salt

Organic fluorides are widely used in medicine,functional materials,and agricultural chemicals.Polyfluoroaryl compounds are an important part of organic fluorides,so the synthesis method of polyfluoroaryl compounds is very important.However,the synthetic methods of polyfluoroaryl compounds that have been reported so far are still relatively few,and the research on such compounds is very limited.At present,the main reason for the lack of synthetic methods of polyfluoroaryl compounds is due to the limited types of polyfluoroaryl groups and fewer synthetic methods.Therefore,the development of new polyfluoroaryl compounds is a meaningful work.In order to solve these problems,on the basis of previous studies,we consulted related reports and carried out the following work:1. In this paper,pentafluorobenzene is used as the source of polyfluoroaryl groups to realize the pentafluorophenylation reaction of 3-iodo-2-aryl benzoheterocycles.A series of pentafluorophenyl benzoheterocyclic compounds have been synthesized.An effective method for the synthesis of 3-pentafluorophenyl-2-aryl benzoheterocycle has been developed.The method is economical and environmentally friendly.Through a series of screening of catalysts,additives,solvents,reaction time and temperature,the optimal conditions were determined to be 5 mol%Pd?PPh₃?₄,0.75 equivalent of silver carbonate,in DMF,120 ^oC,24h.Under these conditions,the corresponding pentafluorophenyl compounds can be obtained with a maximum yield of 97%.2. In order to further expand the source of pentafluorophenyl fragments,we designed and synthesized a kind of S-?pentafluorophenyl?diarylsulfonium salt containing pentafluorophenyl fragments as pentafluorophenyl functional group transfer reagent.We designed 3 routes to syntheze this pentafluorophenyl reagent and carried out a series of exploration studies on the synthesis of S-?pentafluorophenyl?diarylsulfonium salt,including the reaction of 4-methylphenyl sulfide and 2-?trimethylsilyl?phenyl trifluoromethanesulfonate;the reaction of diphenyl sulfoxide,pentafluorophenyl Grignard reagent and trimethylchlorosilane;the reaction of 4-methylphenylsulfoxide,trifluoromethanesulfonic anhydride and benzene.Finally,the reaction of 4-methylphenyl sulfoxide and trifluoromethanesulfonic anhydride in dichloromethane under 0 ^oC-25 ^oC gave the target product S-?pentafluorophenyl?diarylsulfonium salt.Subsequently,a series of reaction explorations were carried out to explore the reactivity of S-?pentafluorophenyl?diarylsulfonium salt.