- Competent Route to Unsymmetric Dimer Architectures: Total Syntheses of (?)-Lycodine and (?)-Complanadines A and B, and Evaluation of Their Neurite Outgrowth Activities
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Valuable synthetic routes to the Lycopodium alkaloid lycodine (1) and its unsymmetric dimers, complanadines A (4) and B (5), have been developed. Regioselective construction of the bicyclo[3.3.1]nonane core structure of lycodine was achieved by a remote functionality-controlled Diels–Alder reaction and subsequent intramolecular Mizoroki–Heck reaction. A key coupling reaction of the lycodine units, pyridine N-oxide (66) and aryl bromide (65), through C?H arylation at the C1 position of 66 provided the unsymmetric dimer structure at a late stage of the synthesis. This strategy greatly simplified the construction of the dimeric architecture and functionalization. Complanadines A (4) and B (5) were synthesized by adjusting the oxidation level of the bipyridine mono-N-oxide (67). The diverse utility of this common intermediate (67) suggests a possible biosynthetic pathway of complanadines in Nature. Both enantiomers of lycodine (1) and complanadines A (4) and B (5) were prepared in sufficient quantities for biological evaluation. The effect on neuron differentiation of PC-12 cells upon treatment with culture medium, in which human astrocytoma cells had been cultured in the presence of 1, 4, or 5 was evaluated.
- Zhao, Le,Tsukano, Chihiro,Kwon, Eunsang,Shirakawa, Hisashi,Kaneko, Shuji,Takemoto, Yoshiji,Hirama, Masahiro
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supporting information
p. 802 - 812
(2017/02/05)
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- Cyclic gyrase and topoisomerase IV inhibitor
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The invention belongs to the technical field of medicament, and particularly relates to a compound shown in formula (I) (please see the formula (I) in the description), and acceptable salt, ester or stereoisomer of the compound in pharmacy. R1, R2, a ring
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Paragraph 0183; 0184; 0185
(2017/01/02)
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- Total syntheses of complanadines A and B
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Twice as nice: Total syntheses of dimeric alkaloids, (-)-complanadines A (1) and B (2), were achieved from (-)-lycodine. The unsymmetrical motif was assembled through direct arylation of the pyridine N-oxide. The absolute configuration and specific rotations of complanadines A and B were identified. Cbz=Benzyloxycarbonyl. Copyright
- Zhao, Le,Tsukano, Chihiro,Kwon, Eunsang,Takemoto, Yoshiji,Hirama, Masahiro
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supporting information
p. 1722 - 1725
(2013/04/10)
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- Inverse electron demand diels-alder reactions of 1,2,3-triazines: Pronounced substituent effects on reactivity and cycloaddition scope
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A systematic study of the inverse electron demand Diels-Alder reactions of 1,2,3-triazines is disclosed, including an examination of the impact of a C5 substituent. Such substituents were found to exhibit a remarkable impact on the cycloaddition reactivity of the 1,2,3-triazine without altering, and perhaps even enhancing, the intrinsic cycloaddition regioselectivity. The study revealed not only that the reactivity may be predictably modulated by a C5 substituent (R = CO2Me > Ph > H) but also that the impact is of a magnitude to convert 1,2,3-triazine (1) and its modest cycloaddition scope into a heterocyclic azadiene system with a reaction scope that portends extensive synthetic utility, expanding the range of participating dienophiles. Significantly, the studies define a now powerful additional heterocyclic azadiene, complementary to the isomeric 1,2,4-triazines and 1,3,5-triazines, capable of dependable participation in inverse electron demand Diels-Alder reactions, extending the number of complementary heterocyclic ring systems accessible with implementation of the methodology.
- Anderson, Erin D.,Boger, Dale L.
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supporting information; experimental part
p. 12285 - 12292
(2011/09/16)
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- N-aryl-piperazinealkanamides useful for improving sleep
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A method of improving sleep in warm-blooded animals suffering from sleep disorders, which method comprises the administration of particular N-aryl-piperazinealkanamide derivatives and compositions containing the same. Novel N-aryl-piperazinealkanamide derivatives.
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- Catalytic Co-cyclisation of α,ω-Cyanoalkynes with Alkynes: a Versatile Chemo- and Regio-selective Synthesis of 2,3-Substituted 5,6,7,8-Tetrahydroquinolines and other Cycloalkapyridines
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α,ω-Cyanoalkynes are catalytically cocyclised with alkynes in the presence of dicarbonyl(cyclopentadienyl)cobalt to furnish annulated pyridines chemo- and regio-selectively.
- Brien, David J.,Naiman, Alaric,Vollhardt, K. Peter C.
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p. 133 - 134
(2007/10/02)
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