- Lewis acid-triggered selective zincation of chromones, quinolones, and thiochromones: Application to the preparation of natural flavones and isoflavones
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A Lewis acid-triggered zincation allows the regioselective metalation of various chromones and quinolones. In the absence of MgCl2, a C(3) zincation is observed, whereas in the presence of MgCl2 or a related Lewis acid, C(2) zincation occurs. Applications to a natural flavone, isoflavone, and quinolone are shown.
- Klier, Lydia,Bresser, Tomke,Nigst, Tobias A.,Karaghiosoff, Konstantin,Knochel, Paul
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supporting information; experimental part
p. 13584 - 13587
(2012/10/08)
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- 2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ) mediated oxidationdehydrogenation of 2-aroyl-3,4-dihydro-2H-benzopyrans : Synthesis of 2-aroylbenzopyran-4-ones
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DDQ mediated an oxidation-dehydrogenation of 2-aroyl-3,4-dihydro-2H- benzopyran prepared from salicylaldehyde to yield 2-aroylbenzopyran-4-one. Stochiometric amount of DDQ, acetic acid and water in refluxing dioxane are the optimal condition for this oxidation-dehydrogenation reaction. A rationally proposed mechanism for this oxidation-dehydrogenation process is based on the isolation of a reaction intermediate viz., 2-benzoyl-8-methoxy-3,4- dihydrobenzopyran-4-one and the identification of the 18O-labled carbonyl group of benzopyran-4-one demonstrating incorporation of labeled H 218O.
- Chen, Liang-Yeu,Li, Sie-Rong,Chen, Po-Yuan,Chang, Ho-Chiang,Wang, Tzu-Pin,Wang, Eng-Chi,Tsai, Ian-Lih
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experimental part
p. 64 - 76
(2010/12/19)
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- Benzenesulfonylimine derivatives as inhibitors of IL-1 action
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The present invention relates to novel benzenesulfonylimine derivatives and their use as inhibitors of Interleukin-1 (IL-1) action. Such inhibitors are useful in the treatment of various disease states as disclosed herein including: rheumatoid arthritis,
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