• Title/Summary/Keyword: CInchona Alkaloid

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Enantioselective Reformatsky Reaction Using Cinchona Alkaloids as Chiral Ligands (Cinchona 알칼로이드를 키랄 리간드로 이용한 비대칭 Reformatsky 반응)

  • Park, Doo-Han;Choi, Ho-Jin;Lee, Sang-Gi
    • Journal of the Korean Chemical Society
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    • v.47 no.6
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    • pp.597-600
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    • 2003
  • Cinchona alkaloids (1-4) were used as chiral ligands for the enantioselective Reformatsky reactions. The order of addition of the Reformatsky reagent to ligands was the important factors for the chiral induction. The ratio of Reformatsky reagent to ligand and aldehyde was also effected on the reaction yields.

Osmylated Macroporous Cinchona Alkaloid Resins: Highly Efficient and Recyclable Catalysts for Asymmetric Dihydroxylation of Olefins

  • Park, Yil-Sung;Jo, Cheon-Hee;Choi, Han-Young;Kwon, Eun-Kyung;Song, Choong-Eui
    • Bulletin of the Korean Chemical Society
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    • v.25 no.11
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    • pp.1671-1675
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    • 2004
  • A simple method for simultaneous recovery and reuse of $OsO_4$ and alkaloid ligand in the asymmetric dihydroxylation of olefins has been developed by using macroporous alkaloid resins bearing residual vinyl groups.

Highly efficient ortho-fluoro-dimeric cinchona-derived phase-transfer catalysts

  • Park, Hyeung-Geun;Jeong, Byeong-Seon;Lee, Jeong-Hee;Yoo, Mi-Sook;Jew, Sang-Sup
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.250.3-251
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    • 2003
  • A series of cinchona alkaloid-derived dimeric quaternary ammonium salts were prepared as chiral phase-transfer catalysts by the introduction of various functional groups on the phenyl ligand. Among them. the 2-F-substituted derivative 21 showed the highest enantioselectivity in the alkylation of the glycine anion equivalent 1 (97->99 % ee).

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Some pharmacological studies with Cycleanine, a diphenylbisbenzylisoquinoline alkaloid from Stephania hernandifolia

  • Maitra, Suparna;Seal, Tapan;Mallik, Sujit;Khasnobis, Arnab;Nandi, RP;Vedasiromoni, J. Rajan;Mukherjee, Biswapati
    • Advances in Traditional Medicine
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    • v.3 no.3
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    • pp.123-128
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    • 2003
  • Stephania hernandifolia belonging to the family Menispermaceae is the biggest storehouse of diphenylbisbenzylisoquinoline (DBBI) alkaloids. Exhaustive chemical processing of the bulb of S. hernandifolia by the application of modern separation techniques yielded a DBBI alkaloid which was identified as cycleanine using spectroscopic methods (UV, IR, $^1HNMR$. $^{13}CNMR$, Mass). Cycleanine showed significant anti-inflammatory activity against carrageenin induced paw oedema, comparable to that produced by diclofenac sodium, used as standard drug. It exhibited potent analgesic effects against chemical and thermal noxious stimuli. It was also found to possess anticonvulsive activity in the strychnine induced convulsion model.