Oxidative Cyclization Reaction And Dearomatization And Cascade Reaction Of Anilines Induced By Hypervalent Iodine Compounds

The hypervalent iodine compounds act as a oxidant in organic reaction, compared with inorganic oxidants, the polyvalent iodines not only have better oxidation resistance, mild reaction conditions, high selectivity, nontoxicity, does not pose a threat to the environment. Since the hypervalent iodine compounds having similar properties with transition metal. In recent years, chemists’study focused on two types of new reaction:1. Oxidative coupling reaction induced by hypervalent iodine compounds.2. Dearomatization reaction of phenols induced by hypervalent iodine compounds. However, the intramolecular oxidative cyclization reaction and the dearomatization of aniline has rarely been studied. However, aniline structure are widely existed in pharmaceutical and biologically active natural products, the synthesis and applications of aniline derivatives and has been the focus of research in organic chemistry.This article aimed the reaction induced by hypervalent iodine compounds.1. Aromatization and cascade reaction of aniline derivatives for construction of polycyclic compounds.2. Oxidative cyclization reaction in synthesis of small ring compounds. The work is divided into two parts.The first part of this study involved cascade reaction of aniline derivatives with a dearomatization strategy. We try to using hypervalent iodine compounds through dearomatization strategy to achieve meta-functionalized anilines. First, a selective C3-C3 oxidative cross-coupling between unactivated anilines and indoles catalyzed by copper bromide together with iodobenzene diacetate as the oxidant is described. This methodology provides a novel approach to biaryl synthesis. The first step of the reaction is most likely the oxidative dearomatization of the aniline derivative. Second, the oxidative dearomatization of para-substituted o-alkynylanilines afforded 2-alkynyl cyclohexadienimines, which can act as active substrates for reaction with electron-rich styrenes. The reaction is metal-controlled. Bi(OTf)3-catalyzed reactions afforded 3,4-dihydro-cyclopenta-[c,d]indoles, and AgOTf-catalyzed reactions provided tricyclic pyrrole derivatives. Third, the oxidative dearomatization of anilines was combined with a domino Michael addition, providing a series of nitrogen-containing bridged bicyclic compounds in moderate to excellent yields. The bridged bicyclic compound could be converted into the corresponding meta carbon-functionalized aniline derivative via amquinine-catalyzed tandem retro-oxa-Michael addition-aromatization reaction. Finally, one pot of deamination reactions to generate Quaternary carbon substituted arene derivatives were described. The reaction undergo a Dearomatization/Knoevenagel condensation/Rearrangement reaction process. These methods give the remarkable chemoselectivity and the wide functional group compatibility.The second part of the study involved oxidative cyclization reaction induced by hypervalent iodine compounds. An efficient oxidative cycloaddition methodology using PhIO with Iodide anion under neutral conditions, which affords 2, 2-difunctionalized aziridines and fused dihydrofuran derivatives in good to excellent yields, is reported. This method can synthesize a lot of High-Strained organic heterocycles.In summary, this dissertation the The dissertation focus on the green chemistry synthetic methodology induced by hypervalent iodine compounds, in order to achieve environmentally friendly, low-cost, convenient synthesis of various cyclic compounds. The two most typical reaction is:1. Oxidative cyclization reaction induced by hypervalent iodine compounds.2. Dearomatization and cascade reaction of aniline derivatives induced by hypervalent iodine compounds.