Study On Non-fluorination Reactions Of Thioether Or Styrenes Involving N-F Reagents

N-F reagents are very useful in organic synthesis.With the deepening of research on N-Freagents,it has been found that in addition to the fluorination reaction of N-F reagents,some N-F reagents can participate in the amination reaction as a nitrogen source;on the other hand,some N-F reagents can also participate in the reaction as oxidant.To investigate the non-fluorination reactions of N-F reagents can deepen the understanding of the nature of such reagents,expand their application and provide new methods for organic synthesis.In this thesis,the research work has been carried out in the following two aspects:amination reaction of aryl sulfides by using NFSI as nitrogen source;Carbon-carbon coupling of styrenes companying by selenization where selectfluor was used as oxidant.1.The aminations of aryl sulfide with NFSI were studied when NFSI was used as a nitrogen source,and the reaction mechanism was also discussed.It was shown that trimethylcyanosilane could remarkably increase the yields of amination reactions for some thioether,and make the reaction proceed smoothly near room temperature.First,we used methyl phenyl sulfide as a substrate to discuss the effects of additives,reaction temperature and solvent on the reaction,and obtained the optimal reaction conditions.That is,when trimethylcyanosilane(1.0 eq)was used as an additive and acetonitrile was used as a solvent,the amination reaction yield(69%)was the highest at 30?under nitrogen atmosphere.Under the conditions,we explored the scope of the substrate.When the thioethers with electron-withdrawing groups at para-position of phenyl ring were used as substrates(such as4-chlorophenyl sulfide,4-bromophenyl sulfide and 4-fluorophenyl sulfide),the additive trimethyl cyanide could greatly increase the yields of amination reaction.Amination could also occur when the electron-withdrawing group is at the ortho or meta position of the aryl sulfide(such as 2-bromophenyl sulfide,2-chlorophenyl sulfide).But the silanes did not increase the yields of the amination reactions for the thioethers with electron-donating groups(such as 4-methylphenyl sulfide,4-methoxyphenyl sulfide,4-ethoxyphenyl sulfide and3-methylphenyl sulfide).(?)2.The reactions of diphenyl selenide with styrenes were studied using Selectfluor as oxidant,and the reaction mechanism was discussed.First,the reaction of styrene with diphenyl diselenide was studied to discuss the effects of reaction temperature,solvent and additives on the reaction.The optimal reaction conditions were obtained.Thus,the acetonitrile was used as a solvent,and the additive trimethylcyanosilane was added,and the mixture was stirred at 80?under an inert gas for 6 hours leading to phenyl 1,3-diphenylallyl selenide in the yield of 55%.Based on these conditions,we discussed the adaptability of the substrate for this reaction.When an aryl olefins(such as 4-ethylstyrene,4-methylstyrene,4-chlorostyrene,3-methylstyrene etc.)were used as substrates respectively,the corresponding selenides can be obtained in the yields of 37%-58%.And the yields of selenization reactions of ortho-or meta-substituted styrenes were lower than those of para-substituted styrenes.However,an alkyl olefin(such as 1-hexene or 3-bromopropene)was used as a substrate,the corresponding product was not obtained.(?)...