- Oxadiazole-substituted naphtho[2,3-b]thiophene-4,9-diones as potent inhibitors of keratinocyte hyperproliferation. Structure?activity relationships of the tricyclic quinone skeleton and the oxadiazole substituent
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Novel analogues of oxadiazole-substituted naphtho[2,3-b]thiophene-4,9-diones were synthesized in which the tricyclic quinone skeleton was systematically replaced with simpler moieties, such as structures with fewer rings and open-chain forms, while the oxadiazole ring was maintained. In addition, variants of the original 1,2,4-oxadiazole ring were explored. Overall, the complete three-ring quinone was essential for potent suppression of human keratinocyte hyperproliferation, whereas analogous anthraquinones were inactive. Also, the oxadiazole ring per se was not sufficient to elicit activity. However, rearrangement of the heteroatom positions in the oxadiazole ring resulted in highly potent inhibitors with compound 24b being the most potent analogue of this series showing an IC50 in the nanomolar range. Furthermore, experiments in isolated enzymatic assays as well as in the keratinocyte-based hyperproliferation assay did not support a major role of redox cycling in the mode of action of the compounds.
- Basoglu, Atila,Dirkmann, Simone,Zahedi Golpayegani, Nader,Vortherms, Silke,Tentrop, Jan,Nowottnik, Dominica,Prinz, Helge,Fr?hlich, Roland,Müller, Klaus
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p. 119 - 132
(2017/04/14)
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- Cu(II)-promoted transformations of α-thienylcarbinols into spirothienooxindoles: Regioselective halogenation of dienyl sulfethers containing electron-rich aryl rings
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Under the promotion of Cu(II) salts, the α-thienylcarbinols with an N-phenyl carbonyl group at the other α-position are converted into three different ranges of spirothienooxindoles involving dearomatizing Friedel-Crafts reaction. In addition, the unprece
- Yin, Biaolin,Huang, Li,Zhang, Xiaoyu,Ji, Fanghua,Jiang, Huanfeng
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p. 6365 - 6370
(2012/09/22)
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- Preparation of new polyfunctional magnesiated heterocycles using a chlorine-, bromine-, or iodine-magnesium exchange
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The reaction of heteroaryl iodides with i-PrMgBr (ca. 1.0 equiv) in THF provides the corresponding magnesiated heterocycles. Functional groups such as an ester, cyano, or chloride functions are tolerated in these new Grignard reagents if the exchange can be performed below -20 °C. This is the case for all heterocycles bearing electron-withdrawing groups or chelating functions facilitating the iodine-magnesium exchange. In many cases, the exchange can be extended to heteroaryl bromides, and a case of a chlorine-magnesium exchange is described with tetrachlorothiophene. This new preparation of functionalized heteroarylmagnesium compounds provides after reaction with various electrophiles a new entry to a broad range of polyfunctional pyridines, imidazoles, furanes, thiophenes, pyrroles, antipyrines, and uracil derivatives. The application of the halogenmagnesium exchange in the solid phase allows the performance of solid-phase synthesis, with potential applications for combinatorial chemistry.
- Abarbri, Mohamed,Thibonnet, Jerome,Berillon, Laurent,Dehmel, Florian,Rottlaender, Mario,Knochel, Paul
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p. 4618 - 4634
(2007/10/03)
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- Heterocyclic amides
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The invention relates to heterocyclic amides of the formula STR1 in which the radicals A, Z, A 1, R 1, R 2 and R 3 are as defined in the description, to a process for the preparation of these amides and to their use as active substances for the curing and
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- Antidiabetic furancarboxylic and thiphenecarboxylic acids
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Compounds of the structure STR1 wherein Z is oxygen or sulfur; R is (C1 -C2)alkoxy; phenoxy; benzyl; phenylthiomethyl; phenylthio; phenylthio monosubstituted in the 2-, 3- or 4-position with (C1 -C3)alkyl, pheny
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