Catalytic Cesium Carbonate Promotes The Selective Cyanation And Trifluoromethylation Of Gem-difluoroalkenes

Fluorine is a special element that ranks the ninth place in the periodic table of elements.It is the most electronegative element in nature,and the radius of the fluorine atom is closest to the radius of the hydrogen atom.Because of the special characteristics of fluorine,therefore,the molecular properties of organic compound can make a huge change when the compound has fluorine atom.For example,the introduction of a fluorine atom into a drug molecule can enhance the binding ability of the drug,change the physical and chemical properties,and improve the metabolic stability and selectivity of the drug,thereby improving the drug efficacy.And with the development of organic fluorine chemistry,organic fluoride has been shown to be more and more widely used in many fields such as biomedicine,chemical pesticides and synthetic materials.Although organic fluorides are widely used,and the synthesis methods of most compounds are relatively simple,transition metals are usually required to participate in the catalysis.Therefore,in combination with the development concept of green chemistry,by using non-transition metal as catalyst to synthetic organic fluoride is one of the hotspots in organic fluorine chemistry in nowadaysThe content of this paper consists of the following two parts:?1?By using catalytic amount of Cs₂CO₃ as catalyst,we have developed an effective and practical method to selective cyanidation of difluorostyrene using TMSCN as the cyanogen source under mild and simple conditions.The reaction yield is moderate to excellent and can be prepared in grams.In addition,a high E/Z selective2-fluoroacrylonitrile compound can be obtained.?2?By using catalytic amount of Cs₂CO₃ as catalyst,we have developed an effective and practical method to selective trifluoromethylation of difluorostyrene using TMSCF₃ as the trifluoromethyl source under mild and simple conditions.The reaction yield is moderate to excellent,and a high E/Z selective 2,3,3,3-tetrafluoroprop-1-ene compound can be obtained.