Cyanation Reactions Of Allylic Alcohols And Aromatic Hydrocarbons With Formamide As The Green Cyanogen Source

Nitriles are important organic compounds that are not only found in numerous natural,pharmaceutical and agronomic products.Moreover,nitriles are also a very important intermediate in organic synthesis,which can be used to synthesize a series of compounds containing functional groups such as amines,amides,aldehydes,ketones and carboxylic acids.The preparation and application of nitrile compounds are of great significance in industrial production,so it is very important to develop different types of cyanation reactions.So far,many methods for synthesizing nitrile compounds using different cyanogen sources have been reported.Among them,the acute toxicity of metal cyanides brings serious environmental problems,and excess cyanide anions can lead to deactivation of metal catalysts,which limits their application in organic synthesis.Therefore,it is of great significance to find a mild green cyanogen source to prepare nitrile compounds.This paper mainly includes two parts.The first part of the research is based on Ni（II）-catalyzed substitution of allyl alcohol with allyl using formamide as a green cyanogen source.At 150 ^oC,under the combined action of nickel and cobalt,formamide will slowly dehydrate to form hydrocyanic acid,which provides a low concentration of cyano groups for the cyanation process,which will effectively avoid the coordination saturation of cyano groups and nickel catalysts and deactivate the catalysts.In addition,formamide can also be used as reducing agent and solvent.The reaction has excellent regioselectivity and good substrate universality.The multiple synthetic uses ofα,β-unsaturated nitriles make this reaction extremely attractive for organic synthesis and medicinal chemistry.The second part is based on Pd（II）-catalyzed C-H bond cyanation of aromatic hydrocarbons and formamide.As a new green cyanogen source,formamide avoids the use of highly toxic metal cyanide.The reaction uses O₂as a mild oxidant for the reaction,which is in line with the green synthesis strategy of atom economy,and has the advantages of low economic cost and green sustainability.The starting materials are simple and easy to obtain,and the range of substrates can be wider through the assistance of the guiding group,and the regioselectivity of the reaction can also be significantly improved.