Asymmetric Oxidative Dearomatization Reactions Of Indoles And Naphthols

This thesis mainly focused on the catalytic asymmetric oxidative dearomatization reactions with the catalysts derived from vanadium and chiral bishydroxamic acid ligands. We not only successfully extended the substrate scope of the catalytic asymmetric epoxidation reaction from simple olefins to aromatic compounds, but also realized asymmetric oxidative dearomatization reactions of indole derivatives and 2-naphthol derivatives with the phenolic hydroxyl as a directing group under the catalysis of chiral vanadium complex. A series of chiral tetrahydroxyfuroindoline compounds, chiral dihydroxybenzopyranindoline compounds and chiral cyclic enone compounds were obtained efficiently by simple operation.In the first part, asymmetric oxidative dearomatization reaction of tryptophol derivatives with alcohol hydroxyl as a directing group was realized under the catalysis of vanadium complex and chiral bishydroxamic acid, affording a series of chiral tetrahydroxyfuroindoline compounds in moderate yields and good enantioselectivity. We successfully expanded the substrate scope of catalytic asymmetric epoxidation reaction from simple olefins to heterocyclic aromatic compounds, such as indoles. A gram-scale reaction was performed and the ee value of this reaction was remained.In the second part, asymmetric oxidative dearomatization reaction of indole derivatives with phenolic hydroxyl as a directing group was achieved under the catalysis of vanadium complex and chiral bishydroxamic acid to provide a variety of products containing chiral dihydroxybenzopyranindoline skeleton with satisfactory yields (up to 83%) and excellent ee (up to 98%). When this reaction was enlarged to gram-scale, the ee value was remained. We reported the first example of catalytic asymmetric epoxidation of indoles with phenolic hydroxyl as a directing group, and expanded the directing group from the alcoholic hydroxyl to the phenolic hydroxyl successfully in metal catalyzed asymmetric epoxidation reaction. This methodology provides a new route for the synthesis of benzoheterocyclic indoline alkaloids.In the third part, asymmetric oxidative dearomatization reaction of naphthol derivatives was realized under the catalysis of vanadium complex and chiral bishydroxamic acid, affording a series of chiral cyclic enone skeleton products in excellent yields and enantioselectivity. This methodology can be used to synthesize the scaffold of some natural products. The direct asymmetric oxidative dearomatization reactions of phenolic substrates were usually developed under the promotion of chiral iodine reagent or chiral copper reagent, however, the yields and the ee value of these reactions were not satisfactory. We explored an asymmetric oxidative dearomatization reaction of naphthol substrates in good yields and excellent enantioselectivity. Moreover, the amount of the catalyst can be reduced to 5 mol%.