Enantioselective and diastereoselective Michael addition of ketone/aldehyde to trans-nitroolefins catalyzed by a novel chiral pyrrolidine-thiourea.


:The direct Michael addition reaction of cyclohexanone/aliphatic aldehydes with nitroolefins, catalyzed by a novel chiral pyrrolidine-thiourea catalyst 1a, is described. The desired 1,4-adducts were obtained in moderate yields with enantioselectivities up to 99% ee and dr up to 99:1 of the syn product.






Shen Z,Zhang Y,Jiao C,Li B,Ding J,Zhang Y




Has Abstract


2007-05-05 00:00:00












  • Importance of hydrogen-bonding sites in the chiral recognition mechanism between racemic D3 terbium(III) complexes and amino acids.

    abstract::The perturbation of the racemic equilibrium of luminescent D3 terbium(III) complexes with chelidamic acid (CDA), a hydroxylated derivative of 2,6-pyridine-dicarboxylic acid (DPA), by added chiral biomolecules such as L-amino acids has been studied using circularly polarized luminescence and 13C NMR spectroscopy. It is...


    pub_type: 杂志文章


    authors: Moussa A,Pham C,Bommireddy S,Muller G

    更新日期:2009-05-01 00:00:00

  • Three-Dimensional Chemical Structure Search Using the Conformational Code for Organic Molecules (CCOM) Program.

    abstract::Searching the 3D structural fragments of organic molecules is challenging because of structural differences between X-ray and theoretically calculated geometries and the conformational flexibility of substituents. The codification program called Conformational Code for Organic Molecules (CCOM) can be used to unambiguo...


    pub_type: 杂志文章


    authors: Izumi H,Nafie LA,Dukor RK

    更新日期:2016-05-01 00:00:00

  • Chemoenzymatic and microbial dynamic kinetic resolutions.

    abstract::This review tracks a decade of dynamic kinetic resolution developments with a biocatalytic inclination using enzymatic/microbial means for the resolution part followed by the racemization reactions either by means of enzymatic or chemocatalyst. These fast developments are due to the ability of the biocatalysts to sign...


    pub_type: 杂志文章


    authors: Kamaruddin AH,Uzir MH,Aboul-Enein HY,Halim HN

    更新日期:2009-04-01 00:00:00

  • Screening Approach for Chiral Separation of β-Aminoketones by HPLC on Various Polysaccharide-Based Chiral Stationary Phases.

    abstract::Nine β-aminoketones were synthesized via Mannich reaction when benzaldehyde was condensed with some primary amines and acetophenone. The purified compounds were identified by using spectroscopic methods. The enantiomeric separation of these derivatives was carried out by high-performance liquid chromatography (HPLC) u...


    pub_type: 杂志文章


    authors: Addadi K,Sekkoum K,Belboukhari N,Cheriti A,Aboul-Enein HY

    更新日期:2015-05-01 00:00:00

  • Conformational equilibria of TADDOL-s in solution investigated by vibrational circular dichroism.

    abstract::Six enantiomeric pairs of TADDOL-s gathered in two series with either methyl (series A) or phenyl (series B) substituent in 2-position of the dioxolane ring were studied by vibrational circular dichroism (VCD). Experimental IR and VCD spectra associated with density functional theory (DFT) calculations showed that the...


    pub_type: 杂志文章


    authors: Uncuta C,Bartha E,Gherase D,Teodorescu F,Draghici C,Cavagnat D,Daugey N,Liotard D,Buffeteau T

    更新日期:2010-01-01 00:00:00

  • Viewing and inducing symmetry breaking at the single-molecule limit.

    abstract::Symmetry breaking by photons, electrons, and molecular interactions lies at the heart of many important problems as varied as the origin of homochiral life to enantioselective drug production. Herein we report a system in which symmetry breaking can be induced and measured in situ at the single-molecule level using sc...


    pub_type: 杂志文章


    authors: Tierney HL,Jewell AD,Baber AE,Iski EV,Sykes EC

    更新日期:2012-12-01 00:00:00

  • Effect of the mobile phase on the retention behavior of optical isomers of the mandelic acid derivative methyl 2-phenyl-2-(tetrahydropyranyloxy) acetate by chiral HPLC.

    abstract::Conditions for separation of enantiomers of a mandelic acid derivative, methyl 2-phenyl-2-(tetrahydropyranyloxy) acetate (the analyte) were studied. Because of the presence of two chiral carbons, the analyte consists of four stereoisomers stable at ambient temperature. Chiral HPLC of the analyte resulted in four peaks...


    pub_type: 杂志文章


    authors: Shen B,Xu X,Chen J,Zhang X,Xu B

    更新日期:2006-09-01 00:00:00

  • Claisen-Schmidt condensation: Synthesis of (1S,6R)/(1R,6S)-2-oxo-N,4,6-triarylcyclohex-3-enecarboxamide derivatives with different substituents in H2 O/EtOH.

    abstract::A simple, green, and direct three-component condensation of acetophenone, aromatic aldehydes with 3-oxo-N-phenylbutanamide (acetoacetanilide) to generate some novel (1S,6R)/(1R,6S)-2-oxo-N,4,6-triarylcyclohex-3-enecarboxamide derivatives was carried out over K2 CO3 (10 mol%) with high efficiency in water/ethanol as gr...


    pub_type: 杂志文章


    authors: Mousavi SR

    更新日期:2016-11-01 00:00:00

  • Circular dichroism and the interactions of water soluble porphyrins with DNA.

    abstract::The size, sign, and profile of induced circular dichroism (CD) features in the Soret region are reliable indicators of the binding modes of porphyrins and metalloporphyrins to DNA. Porphyrins shown (using such CD criteria) to be intercalators in monodispersed DNA duplexes prove extremely useful for the detection and c...


    pub_type: 杂志文章,评审


    authors: Pasternack RF

    更新日期:2003-05-05 00:00:00

  • HPLC enantioseparation and absolute configuration of novel anti-inflammatory pyrrole derivatives.

    abstract::The assignment of the absolute configuration of novel anti-inflammatory pyrrole derivatives has been accomplished by a combined strategy based on independent physical methods. The key step of our stereochemical characterization approach is the production at mg-scale of enantiomerically pure forms by HPLC on Chiralpak ...


    pub_type: 杂志文章


    authors: Biava M,Cirilli R,Fares V,Ferretti R,Gallinella B,La Torre F,Poce G,Porretta GC,Supino S,Villani C

    更新日期:2008-06-01 00:00:00

  • Cucurbituril: chiral applications.

    abstract::This review brings together the past and current methods for synthesizing the classical cucurbit[n]uril (Q[n]), structural variants, and derivatives. Here we refer to the first family of Q[n] as " classical," where the cavity is spheroidal and carry no substituents at any of the equatorial methine carbons or the methy...


    pub_type: 杂志文章,评审


    authors: Mandadapu V,Day AI,Ghanem A

    更新日期:2014-11-01 00:00:00

  • A chiral enantioseparation generic strategy for anti-Alzheimer and antifungal drugs by short end injection capillary electrophoresis using an experimental design approach.

    abstract::The present study describes a generic strategy using capillary electrophoretic (CE) method for chiral enantioseparation of anti-Alzheimer drugs, namely, donepezil (DON), rivastigmine (RIV), and antifungal drugs, namely, ketoconazole (KET), Itraconazole (ITR), fluconazole (FLU), and sertaconazole (SRT) in which these d...


    pub_type: 杂志文章


    authors: Abdel-Megied AM,Hanafi RS,Aboul-Enein HY

    更新日期:2018-02-01 00:00:00

  • Enantiomeric recognition of amino acids using a chiral spiropyran derivative.

    abstract::An optically active spiropyran 1 with a binaphthol moiety as a chiral source was synthesized. The colored merocyanine form of (R)-1 obtained by the UV irradiation remained in the presence of D-amino acids longer than with L-amino acids. ...


    pub_type: 杂志文章


    authors: Tsubaki K,Mukoyoshi K,Morikawa H,Kinoshita T,Fuji K

    更新日期:2002-10-01 00:00:00

  • Improved chiral electrochemical recognition of tryptophan enantiomers based on three-dimensional molecularly imprinted overoxidized polypyrrole/MnO2 /carbon felt composites.

    abstract::A three-dimensional molecularly imprinted overoxidized polypyrrole/MnO2 /carbon felt (MIOPPy/MnO2 /CF) composites were fabricated, which results in increased active area of the surface of the molecularly imprinted polymers film and greatly improved electrochemical chiral recognition effect for tryptophan isomers. The ...


    pub_type: 杂志文章


    authors: Dong L,Liu X,Xu H,Wu D,Gao S,Zhong L,Kong Y

    更新日期:2019-11-01 00:00:00

  • Stereochemical study of tolperisone, a muscle relaxant agent, by circular dichroism and ultraviolet spectroscopy.

    abstract::The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stere...


    pub_type: 杂志文章


    authors: Zsila F,Hollósi M,Gergely A

    更新日期:2000-11-01 00:00:00

  • Natural alkaloids and synthetic relatives as chiral templates of the Orito's reaction.

    abstract::The enantioselective hydrogenation of methyl or ethyl pyruvate over cinchona-platinum catalyst system (Orito's reaction) is one of the most intensively studied heterogeneous catalytic asymmetric hydrogenation reactions. Studies aiming at systematic changes of the chiral template have played a crucial role in creating ...


    pub_type: 杂志文章,评审


    authors: Tálas E,Margitfalvi JL

    更新日期:2010-01-01 00:00:00

  • Chiral bioanalytical methods in bioequivalence studies of intravenous vs. oral formulations of ibuprofen.

    abstract::According to the Ibuprofen Product-Specific Bioequivalence Guidance of the European Medicines Agency, achiral bioanalytical methods are considered acceptable for demonstration of bioequivalence of ibuprofen-containing products. The aim of this investigation is to compare the bioequivalence outcomes obtained with indiv...


    pub_type: 杂志文章


    authors: González-Rojano E,Marcotegui J,Laredo L,Gwaza L,Gordon J,Portolés A,Vargas E,Morales-Alcelay S,García-Arieta A

    更新日期:2020-09-01 00:00:00

  • Substituent effects in the selective reductive opening of epoxides with borohydrides in the presence of beta-cyclodextrin

    abstract::The opening of ortho-substituted phenyl oxiranes by borohydrides is described both in aqueous and solid phases. Some remarkable differences in the regioselectivity and inversion of enantioselectivity of oxirane ring-opening are reported. The results obtained are compared with previous studies and have allowed some fac...


    pub_type: 杂志文章


    authors: Doussot J,Guy A,Siaugue JM,Ferroud C,Guieres AF

    更新日期:1999-01-01 00:00:00

  • Asymmetric Borane Reduction of Prochiral Ketones Catalyzed By Helical Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl].

    abstract::The application of helical poly[(S)-3-vinyl-2,2'-dihydroxy-1, 1'-binaphthyl] (L*) in the asymmetric borane reduction of prochiral ketones was studied. The results showed that L* had excellent catalytic activity as well as enantioselectivity, giving up to 96% yield and up to 99% enantiomeric excess (ee) of the correspo...


    pub_type: 杂志文章


    authors: Qin G,Chen Y,Yang L,Yang N,Yang Z

    更新日期:2015-07-01 00:00:00

  • NMR studies of dextromethorphan in both isotropic and anisotropic states.

    abstract::Herein, we present the solution-state NMR studies on dextromethorphan (1) under both isotropic and anisotropic conditions. From the measurement of 22 residual dipolar couplings using a stretched polystyrene gel (PS), we show that accurate and detailed structural information is readily determined including the relative...


    pub_type: 杂志文章


    authors: Swarbrick JD,Ashton TD

    更新日期:2010-01-01 00:00:00

  • Successful use of a novel lux® i-Amylose-1 chiral column for enantioseparation of "legal highs" by HPLC.

    abstract::Bath salts, fumigations, cleaners and air fresheners, behind these terms substances are hidden, which count as "Legal Highs". These fancy names are used to pretend Legal Highs as harmless compounds, to circumvent legal regulations for marketing as well as to increase the sales. Besides classic illicit drugs of synthet...


    pub_type: 杂志文章


    authors: Kadkhodaei K,Kadisch M,Schmid MG

    更新日期:2020-01-01 00:00:00

  • Stereoselective intramolecular cyclization to 4-(hydroxymethyl)-3-(1H-indolyl)oxazolidin-2-ones.

    abstract::A simple high-yield three-steps route to optically active 4-hydroxymethyl-3-(1H-indolyl)oxazolidin-2-ones from (S)-glycidol is described. The key intermediates (R)-oxiran-2-ylmethyl 1H-indol-4/-5-ylcarbamates are obtained in high yields from (S)-glycidol. These are readily transformed to oxazolidin-2-ones, very intere...


    pub_type: 杂志文章


    authors: Chiummiento L,Funicello M,Tramutola F

    更新日期:2012-04-01 00:00:00

  • Two-dimensional separation of [7]helicene enantiomers on Cu(111).

    abstract::The adsorption of heptahelicene, a helically shaped polyaromatic hydrocarbon (C(30)H(18)), on a Cu(111) surface was studied by means of thermal desorption mass spectrometry (TDMS) and low energy electron diffraction (LEED) at temperatures between 130-1,000 K under ultrahigh vacuum (UHV) conditions. The molecule in the...


    pub_type: 杂志文章


    authors: Ernst KH,Kuster Y,Fasel R,Müller M,Ellerbeck U

    更新日期:2001-01-01 00:00:00

  • Chiral counter-current chromatography: A survey of its instrument, mechanism, procedure, and applications.

    abstract::The chiral separation by counter-current chromatography has made great progress in the past three decades. It has become increasingly popular in the field of chiral separation, and many applications have been introduced during the last years. This review mainly focuses on the current topics, applications, and trends i...


    pub_type: 杂志文章,评审


    authors: Duan WD,Huang XY,Di DL

    更新日期:2020-10-01 00:00:00

  • Optical resolution of 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline by supercritical fluid extraction.

    abstract::6-Fluoro-2-methyl-1,2,3,4-tetrahydroquinoline (FTHQ) enantiomers were separated by supercritical fluid extraction using carbon dioxide. Diastereoisomeric salts were formed from the racemic base with less than one equivalent of O,O'-di-(4-toluoyl)-(2R,3R)-tartaric acid (DPTTA). Further purification was achieved by part...


    pub_type: 杂志文章


    authors: Kmecz I,Simándi B,Bálint J,Székely E,Fogassy E,Kemény S

    更新日期:2001-01-01 00:00:00

  • Single-walled carbon nanotube absolute-handedness chirality assignment confirmation using metalized porphyrin's supramolecular structures via STM imaging technique.

    abstract::This work reports confirmation of the experimental assignment of the absolute-handedness chirality of single-walled carbon nanotubes (SWNTs). This was achieved by applying the scanning tunneling microscopy (STM) imaging technique to a supramolecular composite consisting of a metalized porphyrin derivative (nickel-5,15...


    pub_type: 杂志文章


    authors: Abd El-Mageed AIA,Ogawa T

    更新日期:2020-03-01 00:00:00

  • Stereochemical preference of 2'-deoxycytidine for chiral bis(diamido)-bridged basket resorcin[4]arenes.

    abstract::Bis(diamido)-bridged basket resorcin[4]arene (all-S)-1 and its (all-R)-1 enantiomer proved able to interact with 2'-deoxycytidine (2) and pyrimidine nucleoside analogs in dimethyl sulfoxide (DMSO) solution. In such a solvent, the resorcinarene hosts adopt a preferential 1,3-alternate-like conformation, with a larger c...


    pub_type: 杂志文章


    authors: D'Acquarica I,Calcaterra A,Sacco F,Balzano F,Aiello F,Tafi A,Pesci N,Uccello-Barretta G,Botta B

    更新日期:2013-12-01 00:00:00

  • Tautomerism of 4-hydroxy-2,5-dimethyl-3(2H)-furanone: evidence for its enantioselective biosynthesis.

    abstract::Chiral natural flavor compounds exhibit characteristic enantiomeric excesses due to stereoselective, enzymatically catalyzed reactions during biogenesis. Although the enzymatic formation of the strawberry key flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol(R)) is anticipated, the naturally occurr...


    pub_type: 杂志文章


    authors: Raab T,Hauck T,Knecht A,Schmitt U,Holzgrabe U,Schwab W

    更新日期:2003-08-01 00:00:00

  • Chiral doping of nematic phases and its application to the determination of absolute configuration.

    abstract::Doping nematic liquid crystals with nonracemic chiral compounds induces a twisted nematic (cholesteric) phase. The ability of solutes to twist the nematic phase may be related to the overall shape of the chiral dopant and consequently to its absolute configuration. The cholesteric induction is therefore a powerful too...


    pub_type: 杂志文章


    authors: Pieraccini S,Ferrarini A,Spada GP

    更新日期:2008-05-15 00:00:00

  • Heparin-induced circular dichroism of an achiral, bicyclic species.

    abstract::Antimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. "Mad Cow" disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy te...


    pub_type: 杂志文章


    authors: Stanley FE,Warner AM,McWilliams KM,Stalcup AM

    更新日期:2011-01-01 00:00:00