Study On Difunctionalization Of Alkenes With Sodium Trifluoromethanesulfinate As The Trifluoromethyl Source

Organic compounds containing trifluoromethyl?CF₃?groups have been widely applied in agriculture,medicine and materials fields.Therefore,how to introduce a trifluoromethyl group to target compounds with high efficiency and convenience is always a hot research topic.In this paper,sodium trifluoromethanesulfinate?Langlois reagent?was used as CF₃source,and two methods of introducing trifluoromethyl group to target compounds have been developed by bifunctional strategy.The aminotrifluoromethylation and trifluoromethylation-peroxidation of alkenes were realized.1.The intramolecular aminotrifluoromethylation of alkenes using inexpensive,readily available CF₃SO₂Na as the CF₃ source is described.Under the simple copper salt/TBHP system,a five-membered ring and C-CF₃ bond can be constructed simultaneously,and the reaction conditions are mild and with good functional group tolerance.N-Ts-2-allylaniline as the model substrate to screen the optimal conditions,the optimal reaction conditions involve the use of 1 equivalent Cu?TFA?₂·xH₂O,2 equivalent of CF₃SO₂Na and 3equivalent of TBHP in CH₃CN at 65°C in 73%yield.By investigating the applicability of substrates,and various CF₃-containing indoline,pyrrolidine,lactam and lactone have been obtained.Preliminary mechanism studies indicate that the reaction may be initiated by the addition of CF₃ radical,and finally the target product is obtained by oxidized and the cyclization.2.Using CF₃SO₂Na as the CF₃ source,the trifluoromethylation-peroxidation of olefins was achieved through the bifunctional strategy under the participation of peroxide.In this reaction,peroxide was used not only as a radical initiator,but also as a coupling partner.4-allylanisole as the model substrate to screen the optimal conditions,which are 10 mol%of Co?OAc?₂·4H₂O,2 equivalents of CF₃SO₂Na,6.5 equivalents of TBHP,0.6 equivalents of K₃PO₄ in CH₃CN at 75°C in 79%yield,Both the catalyst and the CF₃ source are cheap and easily available.A variety of allyl,vinyl,chain terminal and internal alkenes with different functional groups are well tolerated in this transformation.Moderated to good yields of the expected products were obtained.In addition,by further conversion of the peroxisome,alcohols and ketones with CF₃ groups were obtained,which is useful in the organic synthesis.