Research On The Cu-promoted Decarboxylative Halogenation With Cheap NaX(X = I,Br,Cl) As Halogen Source

As an important structural motif,aryl halide is one of the most prevalent building blocks in biology,material and drugs.In addition,due to the reactivity of sp2 C-X bond under the promotion of transition metal,great progress and wide application has been achieved in the traditional coupling reactions with aryl halide.Thus,the preparation of aryl halides is currently an attractive research topic in organic synthetic chemistry.Aryl carboxylic acids are readily available,stable and non-toxic compounds,which liberate innocuous carbon dioxide as the by-product during decarboxylation.The aryl-metal intermediates generated from transition metal-mediated decarboxylation may serve as either nucleophile or electrophile depending on the nature of the transition metal salt used for decarboxylation.Therefore,it's a convenient method to construct aryl halide via tranistion metal-mediated decarboxylative halogenation with the appropriate halogen source and aryl carboxylic acid.It is noteworthy that few examples of the decarboxylative halogenation of aryl carboxylic acids have been reported,however,the methods are generally limited to one or two types of C-X bond formation with expensive or heavy metal halide as haogen source(CuX?CuX2?DIH?X2,etc.).Therefore,it's highly desirable to develop a general methodfor decarboxylative halogenation with cheap and stable NaX as halogen source.With using cheap NaX(X = I,Br,Cl)as halogen source,main content in the dissertation includes:1)the development of Ag/Cu bimetallic mediated decarboxylative halogenation of aryl carboxylic acids,research on the reaction mechanism and application of the method;2)the development of Cu-catalyzed decarboxylative iodination of aryl carboxylic acid with NaI in view of the use of noble metal Ag and excessive amount of Cu in the above method,and the application of this method to drug preparation.