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981.
A variety of 4-bromo-3-arylsydnones can be debrominated with sodium dithionite in excellent yield under very mild conditions. 相似文献
982.
Diels–Alder reactions of 3-vinylindoles were carried out with methyl acrylate and N-phenylmaleimide as dienophiles under microwave conditions to furnish unreported tetrahydrocarbazoles regio- and stereoselectively in good yields. Further dehydrogenation resulted in new substituted carbazoles. 相似文献
983.
A series of eight N1-(β-D-ribofuranosyl)-C4-(coumarin-4′′-yl)-1,2,3-triazoles have been synthesized by Cu(I)-catalyzed click reaction of 1-azido-1-deoxy-2,3,5-tri-O-benzoyl-β-D-ribofuranose with differently substituted 4-ethynylcoumarins followed by debenzoylation of the resulted N1-(2′,3′,5′-tri-O-benzoyl-β-D-ribofuranosyl)-C4-(coumarin-4″-yl)-1,2,3-triazoles in 71 to 89% overall yields. The structures of all the synthesized compounds were established on the basis of their spectral data analysis that was further confirmed by X-ray data analysis of one of the model benzoylated compounds, i.e. N1-(2′,3′,5′-tri-O-benzoyl-β-D-ribofuranosyl)-C4-(7″-isopropoxycoumarin-4″-yl)-1,2,3-triazole. 相似文献
984.
《合成通讯》2013,43(21):3263-3271
ABSTRACT Regio- and stereoselective radical addition of α-allenic alcohols with p-TsBr in the presence of a catalytic amount of AIBN afforded (E)-γ-bromo-β-sulfonyl allylic alcohols in moderate yields. The base-promoted 1,4-elimination followed by isomerization to give β-sulfonyl-α,β-unsaturated ketones is described. 相似文献
985.
High quality assays are needed in drug discovery to reduce the high attrition rate of lead compounds during primary screening. Capillary electrophoresis (CE) represents a versatile micro-separation technique for resolution of enzyme-catalyzed reactions, including substrate(s), product(s), cofactor(s) and their stereoisomers, which is needed for reliable characterization of biomolecular interactions in free solution. This review article provides a critical overview of new advances in CE for drug screening over the past five years involving biologically relevant enzymes of therapeutic interest, including transferases, hydrolases, oxidoreductases, and isomerases. The basic principles and major configurations in CE, as well as data processing methods needed for rigorous characterization of enzyme inhibition are described. New developments in functional screening of small molecules that modulate the activity of disease-related enzymes are also discussed. Although inhibition is a widely measured response in most enzyme assays, other important outcomes of ligand interactions on protein structure/function that impact the therapeutic potential of a drug will also be highlighted, such as enzyme stabilization, activation and/or catalytic uncoupling. CE offers a selective platform for drug screening that reduces false-positives while also enabling the analysis of low amounts of complex sample mixtures with minimal sample handling. 相似文献
986.
6-Triazolylpyridone derivatives were synthesized by coupling 4-(4-methoxyphenyl)-6-(1H-1,2,4-triazol-1-yl)-1-(3-chlorophenyl)pyridin-2(1H)-one with substituted benzenediazonium chlorides in the form of two isomers, which were separated by column chromatography and characterized by 1H and 13C NMR. Following the green approach, solvents were avoided as much as possible. The reaction monitoring was carried out by gas chromatography as well as thin-layer chromatography. The scope and limitation of the method are discussed. The structures of all the compounds have been assigned unambiguously on the basis of elemental analysis, infrared, and NMR spectral data and have been evaluated for antimicrobial and antitubercular activities. 相似文献
987.
Benzoylmethyltriphenylarsonium bromide 6 in the presence of potassium carbonate reacted with 2,2-dialkyl-1,3-dioxa-5-substituted-benzylidene-4,6-dione 2 at room temperature to give β,γ-trans-β-benzoyl-γ-aryl-γ-butyrolactones 7 in good yield. 相似文献
988.
Nano-TiO2 is an effective heterogeneous catalyst for the ring opening of epoxides with aromatic amines to afford β-amino alcohols in good to excellent yields at room temperature under solvent-free conditions. It was found that the catalyst is recyclable, and the activity of the catalyst was not weakened markedly even after several reaction cycles. In addition, the catalytic activity of TiO2 strongly depends on particle size or surface area. 相似文献
989.
Two versatile strategies for the synthesis of mimics of the Fusarium mycotoxin zearalenone (1) have been developed. Optimized preparation of (E)-6-(1-alkenyl) substituted β-resorcylic acid esters was realized via ortho-directed lithiation of variable substrates combined with allylation/isomerization or via formylation/Schlosser–Wittig olefination using different protective group patterns. Spontaneous decarboxylation of (E)-6-(1-alkenyl) substituted β-resorcylic acids indicated the influence of this substituent on the chemical behavior of these compounds. These mimics were already used for the development of optimized standard protocols for the synthesis of phase II metabolites of ZEN (glucosides, glucuronides), and further applications (i.e., sulfate conjugates) are still under investigation. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
990.
The title compound, 4β,6α,9α-trimethy-2-carboxyltricyclo[6.3.0.0^(4,5)]undec-2-ene, is a sesquiterpene which was first isolated from Ligularia caloxantha and characterized by MS and NMR. In addition, the structure was determined by X-ray single-crystal diffraction. It crystallizes in orthorhombie, space group P212121 with a = 8.197(2), b = 14.876(3), c = 22.281(6) A, α = β = γ = 90°, V = 2716.9(11) ]A^3, Z = 8, C15H22O2, Mr = 234.34, Dc = 1.146 g/cm^3, μ(MoKa) = 0.074 mm^-1, F(000) = 1024, the final R = 0.0384 and wR = 0.0856 for 6200 independent reflections (Rint = 0.066) and 2538 observed ones (I 〉 2σ(I)). In the molecule, there are three fused five-membered rings; while in this crystal form, the asymmetric unit contains two molecules of the same hand and they are linked together by two intermolecular O-H...O hydrogen bonds to form a dimer. 相似文献