Studies On Metal-Catalyzed Carbon-Carbon Double Bond Fluoroarylation And Trifluoromethylation

Two novel metal-catalyzed carbon-carbon double bond fluoroarylation and trifluoromethylation reactions have been demonstrated in this thesis, which is divided into three sections as following.Chapter1begins by reviewing the development of studies on fluorinated compounds and Pd-catalyzed oxidative Heck coupling reaction. The oxidative Heck-type reaction has been described in details.(1) The development of oxidative Heck reaction, also called Fujiwara-Moritani reaction using stoichiometric Pd(â…¡) has been demonstrated;(2) The development of Pd(â…¡)-catalyzed oxidative Heck reaction of heteroaromatics with alkenes has been depicted.(3) The advance of Pd(â…¡)-catalyzed oxidative dehydrogenative coupling reactions of substituted arenes with alkenes has also been described. In addition, the development of trifluoromethylation and difluoromethylation of carbon-carbon double bond has also been demonstrated in this section.Chapter2summarizes a novel protocol to synthesize fluorinated-aryl substituted styrenes and its derivatives via an oxidative Heck-type reactions of fluorinated arenes with electron-rich alkenes. We found that the reaction of various fluoroarenes with substituted allylic esters can effectively give the corresponding fluoroaryl olefins under the conditions:palladium acetate as catalyst, silver acetate as oxidant, dimethyl sulfoxide as ligand and tetrahydrofuran as solvent. The scope of this system and the possible mechanism has also been studied. It is noteworthy that the electron-rich alkenes such as allylic esters and ethers have been used as the coupling partners in the oxidative Fujiwar-Moritani reactions of fluorinated arenes with olefins for the first time. Under the reaction conditions, the traditional good leaving group OAc has been tolerated in this system.Chapter3demonstrates a Cu(â…¡)-catalyzed decarboxylative trifluoromethylation and Fe(II)-catalyzed difiuoromethylation of a,p-unsaturated carboxylic acids via a radical addition and elimination process. We found that the cinnamic acids can be decarboxylative trifluoromethylation under the condition:Copper(â…¡) sulfate pentahydrate as catalyst, TBHP as radical initiator, Langlois reagent as the trifluoromethyl reagent; Under similar reaction conditions, the cinnamic acids can be also decarboxylative difluoromethylation using Baran reagent catalyzed by Fe(II) via a radical process.Finally, the two novel protocols developed by us have been summarized in the last section. Additionally, the possible future work plan has also been outlined.