ChemInform Abstract: The Synthesis and Reactions of β‐Imidazolylenones

Abstract

As the analogues of acylimidazoles and β-aminoenones, the synthesis and the chemical properties of β-imidazolylenones were reviewed. The synthetic routes from β-haloenones, ynones and α, β-dibromoketones were described. By the reaction with pyrrolidine, the titled compounds are reactive as much as the β-haloenones. The quaternarization of the titled compounds by the treatment with methyl iodide increases the reactivity to the nucleophiles. As the nucleophiles, primary alcohols, phenols, thiols, amines, Grignard reagents and sodium borohydride are employed, and the replaced produts are obtained regioselectively. Also the titled compounds were shown to be useful for the starting materials of the various heterocycles by the treatment with the ambident nucleophiles such as hydroxylamine, hydrazines and ureas. The application of the synthetic procedure for β-chloroenones β-benzimidazolylenones gives β, β-diazolylenones, which were demonstrated as the good precursor of the acylketene derivatives. In conclusion, the titled compounds were shown to be much useful for the syntheses of β-substituted enones and various heterocycles.