Decarboxylative Halogenation and Cyanation of Electron-Deficient Aryl Carboxylic Acids via Cu Mediator as Well as Electron-Rich Ones through Pd Catalyst under Aerobic Conditions

Simple strategies for decarboxylative functionalizations of electron-deficient benzoic acids via using Cu­(I) as promoter and electron-rich ones by employing Pd­(II) as catalyst under aerobic conditions have been established, which lead to smooth synthesis of aryl halides (−I, Br, and Cl) through the decarboxylative functionalization of benzoic acids with readily available halogen sources CuX (X = I, Br, Cl), and easy preparation of benzonitriles from decarboxylative cyanation of aryl carboxylic acids with nontoxic and low-cost K4Fe­(CN)6 under an oxygen atmosphere for the first time.