Silver-Catalyzed Synthesis Of ?-Carbonyl-?-Iminonitriles

In the past few decades,C-H bond activation has been one of the hot research topics in organic chemistry.The C(sp~3)-H bond activation attracts intensive attentions due to its outstanding advantages.Metal-catalyzed isocyanide insertion into C-H bond is a very effective path to synthesize novel organic compounds.In this thesis,an efficient silver triflate-catalyzed C(sp~3)-H bond activation reaction of benzyl tert-butyl ethers with tert-butyl isocyanide was developed to give?-carbonyl-?-iminonitriles in high yields.The given method simultaneously constructs three different functional groups including a carbonyl group,a nitrile group and an imine group in a one-step reaction,which features the characteristics of easy preparation of raw materials,high yields and wide scope of substrates.The thesis contains the following three parts:In the first part,the progress of the reactions involving benzyl tert-butyl ethers was introduced.The progress of silver-catalyzed isocyanide related reactions and the construction of?-carbonyl-?-iminonitriles was also described.At last,the proposal of this thesis was presented.In the second part,an efficient method for synthesizing benzyl tert-butyl ethers was developed.Based on the previously reported methods,a series of benzyl tert-butyl ethers were synthesized by the reaction of benzyl chloride or benzyl bromide with potassium tert-butoxide.Alternatively,tert-butyl ethers could be also obtained from the substituted benzyl alcohols and tert-butanols.In the third part,the synthesis of?-carbonyl-?-iminonitriles were developed through AgOTf-catayzed reaction of benzyl tert-butyl ethers and tert-butyl isocyanide.The reaction conditions were optimized using DDQ as an oxidant and chlorobenzene as solvent.A series of?-carbonyl-?-iminonitriles have been synthesized efficiently from simple benzyl tert-butyl ether derivatives.Furthermore,the transformations of produced?-carbonyl-?-iminonitriles were investigated to afford corresponding quinoxalines,1,3-diazoles,quinoxaline-1,4-dioxides,?-hydroxyl-?-iminonitriles and?-amino-?-hydroxyl-nitriles efficiently via nucleophilic substitution,nucleophilic addition,and oxidation reaction.Finally,a plausible mechanism for the silver triflate-catalyzed reaction of benzyl tert-butyl ethers and tert-butyl isocyanide was proposed.