Studies On The Addition Reactions Of γ-Oxo-α, β-Unsaturated Esters

γ-Oxo-α,β-unsaturated esters are a class of electron-deficient alkenes with multi-functional groups.The dissertation studied the regioseletive addition of several nucleophiles toγ-oxo-α,β-unsaturated esters.The contents consist of two parts.The first part studied the regioselective addition of C-nucleophiles such as indoles, nitroalkanes and 1,3-dicarbonyl compounds toγ-oxo-α,β-unsaturated esters.It was founded that,catalyzed by anhydrous FeCl₃,indole and substituted indoles underwent the regioselective conjugate-addition reaction smoothly with their 3-position,thus providing a practical method for the synthesis of 3-substituted indole derivatives;With t-BuOK as a catalyst,the conjugate addition between nitroalkanes andγ-oxo-α,β-unsaturated esters proceeded smoothly at room temperature and gave the correspondingα-(β'-nitro)-substitutedγ-aryl-γ-oxobutanoates in good yields;By using K₂CO₃ as a catalyst,1,3-dicarbonyl compounds underwent conjugate conditons toγ-oxo-α,β-unsaturated esters efficiently with high regioselectively,thus providing a practical method for the synthesis of multi-functionalized 1,3-dicarbonyl compounds,The second part focused on the bis-addition of substituted hydrazines to a variety ofγ-oxo-α,β-unsaturated esters so as to synthesize heterocyclic compounds.With methylhydrazine as the substrate,the cyclization reaction proceeded smoothly at room temperature without any catalyst to afford 4,5-dihydro-1H-pyrazole derivatives,where the two nitrogen atoms attacked respectively the 2- and 4- position ofγ-oxo-α,β-unsaturated esters.While with arylhydrazines as the substrates,the cyclization proved difficult and reflux conditions were required.In addition,the pyrazole derivatives were obtained,which were deduced to result from the automatical dehydrogenation of 4,5-dihydro-1H-pyrazoles.