Hydrocarbon Activation Reaction Synthesis Of Aromatic Nitrile Compounds

Aromatic nitriles exist extensively in natural products, agrochemicals and pharmaceuticals. The cyano groups as key intermediates in the fine organic chemistry can be easily transformed into other functional groups. For the moment, some drawbacks exist in the common synthesis of aromatic nitriles including the use of toxic reagents and the harsh reaction conditions. Due to the mild reaction conditions and the preclusion of pre-activation for substances, directing groups assisted C-H activation reaction has emerged as an alternative route to preparing nitriles. A new N,N-bidentate directing group assisted, palladium catalyzed C-H cyanation system has been developed in this thesis. The derivatizations of the prepared nitriles were also studied.Firstly, according to C-H activation, the new substrates containing a N,N-bidentate acylamino group have been designed, and the synthetic method of N-(naphthalene-1-yl) picolinamides was improved. Thirteen N-(naphthalene-1-yl) picolinamide derivatives were synthesized with the optimal conditions. The improved method obtained the desired product in high yield under a simple work-up operation.Secondly, the novel N,N-bidentate chelated directing group assisted, palladium catalyzed C-H cyanation system using nontoxic K4Fe(CN)6 as cyanide source has been developed. The optimal reaction conditions was obtained by screening of catalysts, oxidants, solvents, temperature, the equivalents of K4Fe(CN)6 and reaction atmosphere. Thirteen nitriles were synthesized with the optimal catalytic system. The use of relative nontoxic K4Fe(CN)6 allowed the reaction proceed under a mild and environmentalfriendly condition. The cyanation mechanism has also been specluted.Finally, the prepared nitriles were transformed into different derivatives including tetrazoles, carboxylic acids and amides. The further derivatization can be easily preceded due to the halo atoms containing in the structures.