Research On Photoinduced Cyanomethylation Of Diaryl Allyl Alcohols For The Synthesis Of δ-Ketonitriles

δ-ketonitriles are attributed to the ketonitrile compounds,which contain both the carbonyl and nitrile groups.In particular,δ-ketonitrile is one of the most valuable classes of intermediated for the synthesis ofα-aminated ketones,α-hydroxyketones and chiral lactones in organic chemistry.In the thesis,the reaction of diaryl allyl alcohols with bromoacetonitrile via radical addition and 1,2-aryl migration under visible light irradiation has been realized,obtainingδ-ketonitriles in good yields within short time.The main research contents of the dissertation are shown as follows:1.A novel and visible-light-induced protocol to theδ-ketonitriles has been developed from diaryl allyl alcohols and bromoacetonitrile.The reaction was efficient via utilizing Ir（ppy）₃ as photocatalyst,NaOAc as base,and methol/water（CH₃OH/H₂O=30:1）as solvent under 3 W blue LED（λ=450⁴65 nm）irradiation in Ar atmosphere for 4.5 h,affordingδ-ketonitriles in good to excellent yields（Scheme1）.2.The result of mechanistic studies indicated that the reaction ofα,α-diaryl allyl alcohol and bromoacetonitrile could not occur without photocatalyst or visible light.The visible-light-induced cyanomethylation reaction was obviously quenched in the presence of radical scavenger 2,2,6,6-tetramethylpiperidinooxy（TEMPO）or butylated hydroxytoluene（BHT）,and cyanomethyl radical was founded by ESI-MS.These results suggested that a radical pathway was probably involved in this reaction.According to the relevant literatures and the experimental results,the possible reaction mechanism was presented:（Scheme 2）...