Pd Catalyzes The Coupling Reaction Of Chlorinated Fluoroolefins

Fluorinated organic compounds play a significant role in the fields of pharmaceutical,agrochemical and material science,and have gained increasing attention recently.HCFO-1233xf(2-chloro-3,3,3-trifluoroprop-l-ene)is widely used as refrigerant with low price.While very few reports related to its synthesis or chemical transform/conversion have been reported so far.This greatly restrains the research and further application,and thus leads to an urgent and challenging problem to be solved.Trifluoromethylstyrene derivatives have been used as pharmaceutical intermediates as well as the organic light emitting diode(OLED)materials.However,the currently existing methods to synthesize the trifluoromethylstyrene derivatives are not simple and economically viable.In view of these facts,the exploration of using HCFO-1233xf as a reagent to synthesize some trifluoromethylstyrene derivatives,can not only extend the application of HCFO-1233xf,but also propose a new and economical route(s)for the synthesis of trifluoromethylstyrene derivatives.Owing to the obvious advantages of Heck reaction and Suzuki reaction in the direct construction/fonnation of C-C bond,the methodology of these two reactions was adopted in this thesis.The main contents and brief conclusion are summarized as follows:(1)Palladium-catalyzed Heck reaction of fluorinated vinyl chlorideA new method for the direct synthesis of 2-(3-trifluoromethyl-buta-1,3-dienyl)-naphthalene via palladium-catalyzed Heck reaction is explored using HCFO-1233xf and 2-vinyl-naphthalene as the reactants.The optimized conditions of the above mentioned reaction are obtained as follows:The dosages of Pd(OAc)2 and 1-(2-methoxyphenyl)-2-(dicyclohexylphosphino)pyrrole(B)are 6 and 10 mol%,respectively.NaHCO3 is two equivalents of the substrates.The reaction is carried out at 100 ? in N2 atmosphere with a pressure of 10 atm,using DMF(2 mL)as the solvent,and the reaction time is 14 h.The targeted product was obtained with a yield of 55%.The proposed new catalyst system can be applied to the Heck reaction of olefin with strong electronic withdraw group.And thus can effectively expand the application scope of the Heck reaction.(2)Palladium-catalyzed Suzuki reaction of fluorinated vinyl chloride An efficient palladium-catalyzed Suzuki cross-coupling reaction between fluorinated vinyl chloride and arylboronic acids is investigated,through which a new concise synthesis route,which can effectively catalyze trifluorinated substrates with strong electronic withdraw groups is extensively used in the efficient synthesis of a and ?,?-trifluoromethyl containing olefins.A maximum yield of 97%is obtained.The optimized conditions of the above mentioned reaction are obtained as follows:the dosages of Pd(PPh)3Cl2 and B are 5 and 10 mol%,respectively.NaHCO3 is two equivalents of the substrates.The reaction is performed at 100 ? using the mixture of 1,4-dioxane and water(4:1,2.5 mL)as the solvent and the reaction time is 14 h.