Manganese-catalyzed C-H Cyanation Reaction With N-Cyano-N-methoxyphenyl-p-toluenesulfonamide

Aryl nitriles are important structural motifs present in various biologically active compounds.Moreover,aryl nitriles can be utilized as versatile and key synthetic intermediates for the synthesis of medicine,pesticide,dye,photoelectric materials,and spices.The transition metal-catalyzed C-H cyanation reactions for the synthesis of aryl nitriles has been developed so far.Hoewever,this type of C-H cyanation reaction usually requires the use of palladium or rhodium catalyst,which is not in conformity with the requirements of sustainable development.One of the important strategies to realize green chemistry is to use cheap and low or non-toxic catalyst as alternative which has received considerable attention.Using manganese catalyst instead of traditional precious metal catalysts,aryl nitriles compounds are constructed successfully via C-H activation of 2-phenylpyridine in this paper.While catalyst,base,cyano-group sources,temperature,amounts of MnBr(CO)5 and Cy2 NH,solvent and reaction time are investigated,respectively,we decide to perform C-H cyanations of the 2-arylpyridines with N-cyano-N-methoxyphenyl-p-toluenesulfonamide in the presence of MnBr(CO)5 and Cy2 NH as catalysts in DCM at 70 oC for 12 h.The research suggested: The reaction tolerates a variety of synthetically important functional groups and no dicyanated products are observed in the reaction.Both the electric effect and steric hindrance can influence the reaction.Furthermore,electron-deficient group gave a lower yield of cyanated product compared to the electron-rich group.Nuclear magnetic resonance(NMR)and high resolution mass spectroscopy(HRMS)are used to characterize cyanation products.