New Synthetic Methods of Aromatic and Heterocyclic Compounds

点击翻译按钮获取中文摘要

Development of various amination reactions has been studied by using oxime derivatives as electrophilic aminating reagents toward the synthesis of heterocycles. Although oxime derivatives generally undergo the Beckmann rearrangement, it was found that S_N2-type reaction on the sp^2 oxime nitrogen proceeds when the oxime having proper leaving group is treated with nucleophile. Various cyclic imines and quinolines are synthesized by the intramolecular reactions. Oximes are found to be the electrophilic aminating reagent for the Grignard reagent to prepare primary amines. Moreover, it was found alkylideneaminylradical species are formed from O-2,4-dinitrophenyloximes by one-electron reduction. This process can be applied to the synthesis of various heterocycles, such as quinolinol, pyrrole and carboline derivatives. Total synthesis of a pyrrolizidine alkaloid, xenovenine, was achieved by applying this radical cyclization reaction of the oxime. Furthermore, it was found that oxidative addition of O-pentafluorobenzoyloximes occurs to Pd (0) complexes, generating alkylideneamidopalladium species. This realized the Pd(0)-catalized transformation of unsaturated ketone O-pentafluorobenzoyloximes to pyrroles, pyridines, isoquinolines and azaazulenes.On synthesis of aromatic compounds, preparation of m-substituted aromatic compounds is one of the important issue. m-Acyl aniline, phenol, alkylbenzene derivatives were prepared regioselectively by the reaction of cyclohexadienone-iron carbonyl complex and higher order cuprate.