Copper-Catalyzed,Directing Group-Assisted Cyanation Of Aryl C(sp~2)-H Bond Using Acetonitrile As A Cyano Source

Aromatic nitriles are an essential part of compounds found in pharmaceuticals,agrochemicals,and dyes.Also they are key intermediates,which can convert into varieties of functional groups,such as carboxyl variants,tetrazoles,aldehydes,amines,amidines and amides.Recently,the strategy of transition metal catalyzed C?H bond functionalization by employing directing group has been paid much attention.The C?H bond cyanation also becomes an important research field.However,the type of the directing groups applying to the cyanation in the previous reports is limited.To our knowledge,only two substrates(2-phenylpyridine and pyrimidine-substituted indoles are applicable.Thus,our group focused on the cyanation by using removable bidentate coordination directing groups.In this thesis,we utilize acetonitrile as the cyano source and realize the cyanation of the sp~2 C?H bond with 2-aminothioether bidentate directing group.Therefore,we choose N-(2-(methylthio)phenyl)benzamide as the substrate,inexpensive copper salt as the metal catalyst,the potassium pivalate as the base,acetonitrile as the solvent.The desired cyanated products could be formed in acceptable yields.The stoichiometric amount of phase transfer reagent would assist this reaction.A series of electron-donating and electron-withdrawing groups are compatible under this system.Meanwhile,the cyanated products can further be converted into phthalimide derivatives under the catalysis of copper salt by adding pyridin-2-ol as the ligand.Then the directing groups can be removed to give corresponding phthalimides.