Enantioselective reduction of ketones with borane catalyzed by tridentate amino alcohols derived from salicylaldehyde.


:In the presence of tridentate chiral ligand 4e, 99% e.e. value was obtained by asymmetric reduction of ethyl benzoylacetate with borane in toluene at 25 degrees C. Various ligands and reaction conditions were investigated to develop a reasonable mechanism that explains the experimental outcomes.






Lee DS




Has Abstract


2007-02-01 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

  • Unexpected rearrangement of enantiomerically pure 3-aminoquinuclidine as a simple way of preparing diastereomeric octahydropyrrolo[2,3-c]pyridine derivatives.

    abstract::Reaction of (S)- or (R)-3-aminoquinuclidine with 2-chloropyrimidine or 2-bromopyrimidine led to an unexpected formation of both cis- and trans-octahydropyrrolo [2,3]pyridine derivatives. A single-step synthesis of two of the four stereoisomers of these octahydropyrrolo[2,3]pyridine derivatives provides a convenient wa...


    pub_type: 杂志文章


    authors: Goljer I,Molinari A,He Y,Nogle L,Sun W,Campbell B,McConnell O

    更新日期:2009-07-01 00:00:00

  • Improving enantiomeric resolutions by avoiding peak distortion effects in on-line coupled liquid chromatography to gas chromatography.

    abstract::In this work, we study the effect of different variables affecting elution profile distortion on the enantiomeric resolution eventually achievable when working with on-line coupled liquid chromatography to gas chromatography (LC-GC). Specifically, the proposed configuration combines achiral reversed-phase liquid chrom...


    pub_type: 杂志文章


    authors: Martínez RM,Barba C,Robredo S,Herraiz M

    更新日期:2019-10-01 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

  • Chiral discrimination by albumin: a mechanistic study of liquid chromatographic optical resolution of nonaromatic carboxylic acids.

    abstract::In order to get further insight into the mechanism by which bovine serum albumin (BSA) discriminates between enantiomers of organic acids, some radioisotopically labeled, nonaromatic carboxylic acids were studied under varying mobile phase conditions. It was found for a series of N-alkanoyl-DL-[3H]leucines that the D-...


    pub_type: 杂志文章


    authors: Allenmark S

    更新日期:1993-01-01 00:00:00

  • Stereoselective sulfation of terbutaline by the rat liver cytosol: evaluation of experimental approaches.

    abstract::Little is known about the stereochemistry of sulfation of chiral phenolic drugs. In this study we examined several in vitro approaches to this question, using (+)-, (-)-, or (+/-)-terbutaline as the substrate and the rat liver cytosol as the phenolsulfotransferase enzyme source. The cosubstrate PAPS was either generat...


    pub_type: 杂志文章


    authors: Walle UK,Walle T

    更新日期:1989-01-01 00:00:00

  • Chiroptical properties of 2,2'-bioxirane.

    abstract::The two enantiomers of 2,2'-bioxirane were synthesized, and their chiroptical properties were thoroughly investigated in various solvents by polarimetry, vibrational circular dichroism (VCD), and Raman optical activity (ROA). Density functional theory (DFT) calculations at the B3LYP/aug-cc-pVTZ level revealed the pres...


    pub_type: 杂志文章


    authors: Daugey N,De Rycke N,Brotin T,Buffeteau T

    更新日期:2018-04-01 00:00:00

  • Resolution of 1-n-butyl-3-methyl-3-phospholene 1-oxide with TADDOL derivatives and calcium salts of O,O'-Dibenzoyl-(2R,3R)- or O,O'-di-p-toluoyl-(2R,3R)-tartaric acid.

    abstract::The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid ...


    pub_type: 杂志文章


    authors: Bagi P,Fekete A,Kállay M,Hessz D,Kubinyi M,Holczbauer T,Czugler M,Fogassy E,Keglevich G

    更新日期:2014-03-01 00:00:00

  • Four conformers characterized in allyl nitrite.

    abstract::Allyl nitrite, O=NOCH(2)CH=CH(2), can exist in conformations which include syn (S) and anti (A) configurations of O=N-O-C, anti or gauche (G) configurations of N-O-C-C, and syn or skew (Sk) configurations of O-C-C=C. Four of them have been observed and characterized by their microwave spectra and quantum chemical calc...


    pub_type: 杂志文章


    authors: Lee SG,Breeze L,Bohn RK,True NS

    更新日期:2002-02-01 00:00:00

  • Chiral separations on polysaccharide stationary phases using polar organic mobile phases.

    abstract::About 30% of a chemically diverse set of compounds were found to separate on four polysaccharide chiral stationary phases using polar organic mobile phases. No structural features appeared to correlate to successful separations. Titrations between normal and polar organic mobile phases suggested that separation mechan...


    pub_type: 杂志文章


    authors: Lynam KG,Stringham RW

    更新日期:2006-01-01 00:00:00

  • Spirobipyridopyrans and indolinospiropyridopyrans: Synthesis, X-ray crystal structure, separation of enantiomers, and barriers to thermal cleavage of the C(sp(3))-O bond.

    abstract::The novel chiral spirobipyridopyrans 1 and 2 were synthesized by the acid catalyzed aldol type condensation of 5-deoxypyridoxal with the appropriate ketone and subsequent reaction of the resulting pyrylium salt with base. The indolinospiropyridopyrans 3-5, which contain the modified B(6) unit, were prepared by aldol r...


    pub_type: 杂志文章


    authors: Loncar-Tomaskovic L,Pustet N,Mrvos-Sermek D,Nagl A,Mintas M,Mannschreck A

    更新日期:2001-02-01 00:00:00

  • The asymmetric synthesis of (R,R)-formoterol via transfer hydrogenation with polyethylene glycol bound Rh catalyst in PEG2000 and water.

    abstract::(R,R)-formoterol was synthesized in seven steps with 4-hydroxyl-3-nitro-acetophenone as the starting material. The key intermediate, the chiral secondary alcohol 4, was prepared via Rh-catalyzed asymmetric transfer hydrogenation with (S,S)-PEGBsDPEN as the ligand and sodium formate as the hydrogen donor under mild con...


    pub_type: 杂志文章


    authors: Huang L,Liu J,Shan W,Liu B,Shi A,Li X

    更新日期:2010-02-01 00:00:00

  • Ion channels as pharmacologic receptors: the chirality of drug interactions.

    abstract::Ion channels are pharmacologic receptors and as such exhibit stereoselective interactions with drugs. Ion channels are conformationally mobile transmembrane proteins existing in a number of open and closed states. Drug interactions with these different states may differ quantitatively and qualitatively. Stereoselectiv...


    pub_type: 杂志文章,评审


    authors: Triggle DJ

    更新日期:1996-01-01 00:00:00

  • Absolute configuration and conformational analysis of a degradation product of inhalation anesthetic Sevoflurane: A vibrational circular dichroism study.

    abstract::1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane, compound B, is a product obtained in the degradation of the anesthetic Sevoflurane. Enantiopure (+)-B was investigated using vibrational circular dichroism (VCD). Experimental absorption and VCD spectra of (+)-B in CDCl(3) solution in the 2,000-900 cm(-1) regio...


    pub_type: 杂志文章


    authors: Wang F,Polavarapu PL,Schurig V,Schmidt R

    更新日期:2002-08-01 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

  • Computational simulation of vibrationally resolved spectra for spin-forbidden transitions.

    abstract::In this computational study, we illustrate a method for computing phosphorescence and circularly polarized phosphorescence spectra of molecular systems, which takes into account vibronic effects including both Franck-Condon and Herzberg-Teller contributions. The singlet and triplet states involved in the phosphorescen...


    pub_type: 杂志文章


    authors: Egidi F,Fusè M,Baiardi A,Bloino J,Li X,Barone V

    更新日期:2018-07-01 00:00:00

  • Stereoselective pharmacokinetics of (R)-(+)- and (S)-(-)-rabeprazole in human using chiral LC-MS/MS after administration of rabeprazole sodium enteric-coated tablet.

    abstract::Rabeprazole is an effective proton pump inhibitor to treat acid-related diseases. To achieve the simultaneous determination of rabeprazole enantiomers in human plasma, a chiral LC-MS/MS method was developed and validated. Acetonitrile including 0.1% ammonium were used as protein precipitating agent. Analytes were sepa...


    pub_type: 杂志文章


    authors: Sun LN,Shen YW,Ying YW,Li D,Li TF,Zhang XH,Zhao P,Ding L,Wang YQ

    更新日期:2018-12-01 00:00:00

  • Spectroscopic studies on nicotine and nornicotine in the UV region.

    abstract::The UV absorption and electronic circular dichroism (ECD) spectra of (R)- and (S)-nicotine and (S)-nornicotine in aqueous solution were measured to a significantly lower wavelength range than previously reported, allowing the identification of four previously unobserved electronic transitions. The ECD spectra of the t...


    pub_type: 杂志文章


    authors: Clayton PM,Vas CA,Bui TT,Drake AF,McAdam K

    更新日期:2013-05-01 00:00:00

  • Isolation and identification of sapotexanthin 5,6-epoxide and 5,8-epoxide from red mamey (Pouteria sapota).

    abstract::Two new carotenoids, sapotexanthin 5,6-epoxide and sapotexanthin 5,8-epoxide, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Sapotexanthin 5,6-epoxide was also prepared by partial synthesis via epoxidation of sapotexanthin, and the (5R,6S) and (5S,6R) stereoisomers were identified by high-perf...


    pub_type: 杂志文章


    authors: Murillo E,Agócs A,Nagy V,Király SB,Kurtán T,Toribio EM,Lakey-Beitia J,Deli J

    更新日期:2020-05-01 00:00:00

  • Investigation of the chiral recognition ability of human carboxylesterase 1 using indomethacin esters.

    abstract::Human carboxylesterase 1 (hCES1) is an enzyme that plays an important role in hydrolysis of pharmaceuticals in the human liver. In this study, elucidation of the chiral recognition ability of hCES1 was attempted using indomethacin esters in which various chiral alcohols were introduced. Indomethacin was condensed with...


    pub_type: 杂志文章


    authors: Takahashi M,Takani D,Haba M,Hosokawa M

    更新日期:2020-01-01 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

  • Liquid chromatographic resolution of 3-amino-1,4-benzodiazepin-2-one derivatives on various Pirkle-type chiral stationary phases.

    abstract::The two enantiomers of N-acyl amide and N-ureide derivatives of 3-amino-5-phenyl-1,4-benzodiazepin-2-ones, which have been known to show anti-respiratory syncytial virus (RSV) activity, were resolved on seven different Pirkle-type chiral stationary phases (CSPs) with the use of 10% isopropyl alcohol in hexane as a mob...


    pub_type: 杂志文章


    authors: Park JY,Cho HS,Hyun MH

    更新日期:2011-01-01 00:00:00

  • Evaluation of the enantiomeric composition of amino acids in tobacco.

    abstract::Despite the fact that several studies have reported the concentrations of various free amino acids in tobacco, their enantiomeric composition is unknown. Both the absolute and enantiomeric compositions of proline, alanine, asparagine, aspartic acid, valine, methionine, leucine,and phenylalanine were determined for thr...


    pub_type: 杂志文章


    authors: Kullman JP,Chen X,Armstrong DW

    更新日期:1999-01-01 00:00:00

  • Experimental methods for measuring optical rotatory dispersion: survey and outlook.

    abstract::The measurement of optical rotation (OR) and optical rotatory dispersion has been finding renewed interest for some years, because of advancement in computational methods and in the performance of new experiments. Here, we shortly review the traditional and most-used experimental methods. We define and discuss the two...


    pub_type: 杂志文章,评审


    authors: Castiglioni E,Abbate S,Longhi G

    更新日期:2011-10-01 00:00:00

  • Chirality as an inherent general property of matter.

    abstract::A statement has been formulated that chirality is an indispensable inherent property of all material objects, at one level of organization of matter or another. The translation of chirality from one level of material objects to another deserves our attention. The parity violation of weak interactions can be discussed ...


    pub_type: 杂志文章


    authors: Davankov V

    更新日期:2006-08-01 00:00:00

  • Enantioselective synthesis of 2- and 3-substituted 2,3-dihydro[1,4]dioxino[2,3-b]pyridine derivatives and enantiomeric purity control by capillary electrophoresis.

    abstract::A rapid and simple procedure for enantioselective preparation of 2- and 3-substituted 2,3-dihydro[1,4]dioxino[2,3-b]pyridine derivatives (A and B, respectively) is described. The enantiomeric purity of each isomer was determined by capillary electrophoresis using a dual-cyclodextrin system (S-beta-CD/beta-CD) dissolve...


    pub_type: 杂志文章


    authors: Lazar S,Soukri M,El Haddad M,Akssira M,Leger JM,Jarry C,Morin P,Guillaumet G

    更新日期:2005-01-01 00:00:00

  • Noncovalent immobilization of ionic-tagged box-Cu(OAc)2 complex and its application in asymmetric Henry reaction.

    abstract::Immobilized Cu(OAc)(2)-bis(oxazolines) via hydrogen bonding by SBA-15 was applied to asymmetric Henry reaction, and good enantioselectivities were obtained (up to 83% ee) between 2-methoxybenzaldehyde and CH(3)NO(2) in isopropyl alcohol (iPrOH). The catalyst could be reused seven times without any obvious loss in enan...


    pub_type: 杂志文章


    authors: Li ZH,Zhou ZM,Hao XY,Zhang J,Dong X,Liu YQ

    更新日期:2012-12-01 00:00:00

  • Circular dichroism eigenspectra of polyproline II and β-strand conformers of trialanine in water: Singular value decomposition analysis.

    abstract::Despite that a number of experimental and theoretical investigations have been carried out to determine the structure of trialanine in water, the reported populations of polyproline II (PPII) and β-strand conformers vary and were found to be dependent on which spectroscopic method was used. Such discrepancies are due ...


    pub_type: 杂志文章


    authors: Oh KI,Lee KK,Park EK,Yoo DG,Hwang GS,Cho M

    更新日期:2010-01-01 00:00:00

  • The first preparation of enantiopure 1-methyl-7-oxabicyclo[2.2.1]heptan-2-one, a versatile chiral building block for terpenoids.

    abstract::Methods for the resolution of (+/-)-1-methyl-7-oxabicyclo[2.2.1]heptan-2-one 1, a versatile chiral building block for terpenoids, have been investigated. While no efficient result was obtained with kinetic resolution methods, both enantiomers of 1 were prepared optically pure for the first time via esterification of t...


    pub_type: 杂志文章


    authors: Guan YK,Li YL

    更新日期:2005-02-01 00:00:00

  • Synthesis of novel camphor-derived bifunctional thiourea organocatalysts.

    abstract::Synthesis and catalyst performance of 2,3- (types and ) and 2,8-disubstituted (type ) thiourea bifunctional organocatalysts was attempted. The synthesis of catalyst of type has, so far, not been realized, while catalysts of type , i.e., the 2,3-exo- and the 2-endo-3-exo-thiourea catalysts, were prepared in six steps s...


    pub_type: 杂志文章


    authors: Ričko S,Golobič A,Svete J,Stanovnik B,Grošelj U

    更新日期:2015-01-01 00:00:00