Enantioselective catalytic reduction of ketoimines with trichlorosilane promoted by readily available chiral Lewis bases.


:The straightforward synthesis of a series of enantiomerically pure Lewis basic amides by simple condensation of commercially available enantiopure diamines with picolinic acid is reported. These compounds were shown to promote the enantioselective reduction of ketoimines with trichlorosilane. Working with the model substrate N-phenyl benzophenone imine, the new organocatalysts led to the formation of the corresponding amine, with excellent chemical efficiency (up to 99% chemical yield) and good stereoselectivity (up to 73% ee). Up to 83% of enantioselectivity was reached in the reduction of differently substituted imines.






Guizzetti S,Benaglia M,Cozzi F,Rossi S,Celentano G




Has Abstract


2009-01-01 00:00:00












  • Enhanced efficiency due to the use of achiral additives in the optical resolution of 1-phenylethylamine by its glutaric acid derivative.

    abstract::Racemic 1-phenylethylamine was optically resolved by its own derivative formed with glutaric acid namely (+)-(R)-N-(1-phenylethyl)glutaramic acid. The amide acid resolving agent was synthesized from (+)-(R)-1-phenylethylamine by N-derivatization. The glutaric acid derivative was the next in a homologous series of dica...


    pub_type: 杂志文章


    authors: Schindler J,Egressy M,Bereczki L,Pokol G,Fogassy E,Marthi K

    更新日期:2007-03-01 00:00:00

  • Chiral 1,1'-binaphthyl-2,2'-dithiol-stabilized gold clusters: size separation and optical activity in the UV-vis.

    abstract::Gold particles covered with 1,1'-binaphthyl-2,2'-dithiol (BINAS) were prepared. Using size exclusion chromatography, it was possible for the first time to separate the sample into fractions with different sizes and colors. Transmission electron microscopy shows that the particles are very small, in the order of 1 nm o...


    pub_type: 杂志文章


    authors: Gautier C,Taras R,Gladiali S,Bürgi T

    更新日期:2008-03-01 00:00:00

  • Chiroptical properties of diamino carboxylic acids.

    abstract::Diamino carboxylic acids have recently come to the attention of scientists working in the field of early life and its development. These are the monomers of a hypothetic early form of genetic material, the so-called Peptide Nucleic Acid (PNA) (Nielson et al., Proc Natl Acad Sci USA 2000;97:3868-3871). Since all biopol...


    pub_type: 杂志文章


    authors: Bredehöft JH,Breme K,Meierhenrich UJ,Hoffmann SV,Thiemann WH

    更新日期:2007-07-01 00:00:00

  • Simultaneous Enantioseparation of Aldohexoses and Aldopentoses Derivatized With L-Tryptophanamide by Reversed Phase HPLC Using Butylboronic Acid as a Complexation Reagent of Monosaccharides.

    abstract::Three aldohexoses, glucose, galactose, and mannose, and three aldopentoses, arabinose, xylose, and ribose, were derivatized with L-tryptophanamide (L-TrpNH2 ) under alkaline conditions. Using a basic mobile phase (pH 9.2), the three aldohexoses or the three aldopentoses were simultaneously enantioseparated, respective...


    pub_type: 杂志文章


    authors: Shou M,Terashima H,Aizawa S,Taga A,Yamamoto A,Kodama S

    更新日期:2015-07-01 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

  • 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

  • Is the optical rotation sign/absolute configuration relationship still a problem? Examples taken from unnatural quaternary aminoacids.

    abstract::The optical rotation sign/absolute configuration relationships of several alpha-methyl-alpha-arylglycines have been reinvestigated by crystallographic methods, as they have been found to be inconsistent in recent literature. Assignments previously made by enzymatic resolution, by analogy with natural tertiary aminoaci...


    pub_type: 杂志文章


    authors: Ferron L,Guillen F,Coste S,Coquerel G,Plaquevent JC

    更新日期:2006-08-01 00:00:00

  • Theoretical Modeling of Surface Confined Chiral Nanoporous Networks: Cruciform Molecules as Versatile Building Blocks.

    abstract::Patterning of solid surfaces with functional organic molecules has been a convenient route to fabricate two-dimensional materials with programmed architecture and activities. One example is the chiral nanoporous networks that can be created via controlled self-assembly of star-shaped molecules under 2D confinement. In...


    pub_type: 杂志文章


    authors: Kasperski A,Szabelski P

    更新日期:2015-07-01 00:00:00

  • A new definition of life.

    abstract::Chirality is often glossed over in theoretical or experimental discussions concerning the origin of life, but the ubiquity of homochiral building blocks in known biological systems demands explanation. Information theory can provide a quantitative framework for understanding the role of chirality in biology. Here I sh...


    pub_type: 杂志文章


    authors: Carroll JD

    更新日期:2009-03-01 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

  • Enantioseparation and determination of the chiral fungicide furametpyr enantiomers in rice, soil, and water by high-performance liquid chromatography.

    abstract::The chiral fungicide furametpyr is widely used in the rice field to control rice sheath blight; however, furametpyr enantiomers are treated as just one compound in traditional achiral analysis, which gives only partial information. An effective chiral analytical method was developed for the resolution and determinatio...


    pub_type: 杂志文章


    authors: Dong F,Chen X,Xu J,Liu X,Chen Z,Li Y,Zhang H,Zheng Y

    更新日期:2013-12-01 00:00:00

  • Stopped-Flow Enantioselective HPLC-CD Analysis and TD-DFT Stereochemical Characterization of Methyl Trans-3-(3,4-Dimethoxyphenyl)Glycidate.

    abstract::Caffeic acid-derived polyethers are a class of natural products isolated from the root extracts of comfrey and bugloss, which are endowed with intriguing pharmacological properties as anticancer agents. The synthesis of new polyether derivatives is achieved through ring-opening polymerization of chiral 2,3-disubstitut...


    pub_type: 杂志文章


    authors: Tedesco D,Fabini E,Barbakadze V,Merlani M,Zanasi R,Chankvetadze B,Bertucci C

    更新日期:2015-12-01 00:00:00

  • Detection of the activity of ion channels and pores by circular dichroism spectroscopy: G-quartets as functional CD probes within chirogenic vesicles.

    abstract::We introduce a method to detect the activity of ion channels and pores with circular dichroism (CD) spectroscopy. G-quartets obtained by potassium templated self-assembly of 5'-guanosine monophosphate (GMP) are used as CD probes, the bee-toxin melittin as representative pore and gramicidin A as representative ion chan...


    pub_type: 杂志文章


    authors: Hennig A,Matile S

    更新日期:2008-09-01 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

  • Chirality and chiroptical properties of amyloid fibrils.

    abstract::Chirality of amyloid fibrils-linear beta-sheet-rich aggregates of misfolded protein chains-often manifests in morphological traits such as helical twist visible in atomic force microscopy and in chiroptical properties accessible to vibrational circular dichroism (VCD). According to recent studies the relationship betw...


    pub_type: 杂志文章,评审


    authors: Dzwolak W

    更新日期:2014-09-01 00:00:00

  • Comparative study on kynurenic acid production in the rat striatum by tryptophan enantiomers: an in vivo microdialysis study.

    abstract::Kynurenic acid (KYNA), an endogenous antagonist of N-methyl-D-aspartate and α(7) nicotinic acetylcholine receptors, is one of the L-tryptophan (Trp) metabolites. To compare the level of KYNA produced in the striatum of rats after independent administration of L-Trp and D-Trp, rats were intraperitoneally administered L...


    pub_type: 杂志文章


    authors: Ishii K,Iizuka H,Ogaya T,Song Z,Fukushima T

    更新日期:2011-01-01 00:00:00

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

    abstract::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. ...


    pub_type: 杂志文章


    authors: Lee DS

    更新日期:2007-02-01 00:00:00

  • Synthesis and characterization of conformationally rigid chiral pyridine-N-heterocyclic carbene-based palladacycles with an unexpected Pd-N bond cleavage.

    abstract::The versatility of a previously developed method for the synthesis of chiral carbene-based palladacycles is demonstrated through the synthesis of two new chiral pyridine-functionalized N-heterocyclic carbene palladacycles with different wingtip groups. The efficiency in their resolution with different counter anions a...


    pub_type: 杂志文章


    authors: Ng KH,Li Y,Tan WX,Chiang M,Pullarkat SA

    更新日期:2013-03-01 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

  • 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

  • Parallel kinetic resolution of an oxazolidinone using a quasi-enantiomeric combination of [D,13C]-isotopomers of pentafluorophenyl 2-phenyl propionate.

    abstract::Parallel kinetic resolution of Evans' phenylglycine derived oxazolidinone using an equimolar combination of quasi-enantiomeric active esters (derived from [D,13C]-labeled 2-phenylpropionic acid) was achieved. The levels of stereocontrol were high, leading to products with predictable configurations. ...


    pub_type: 杂志文章


    authors: Coumbarides GS,Dingjan M,Eames J,Flinn A,Northen J

    更新日期:2007-05-05 00:00:00

  • High-Performance Liquid Chromatographic Enantioseparation of Cyclic β-Amino Acids on Zwitterionic Chiral Stationary Phases Based on Cinchona Alkaloids.

    abstract::Stereoselective high-performance liquid chromatographic separations of eight sterically constrained cyclic β-amino acid enantiomer pairs were carried out using the newly developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+) and ZWIX(-). The effects of the mobile phase composition, t...


    pub_type: 杂志文章


    authors: Ilisz I,Gecse Z,Lajkó G,Forró E,Fülöp F,Lindner W,Péter A

    更新日期:2015-09-01 00:00:00

  • Stereochemical analysis of β-keto sulfoxides by circular dichroism.

    abstract::Three β-keto sulfoxides (1-3) were synthesized in enantiopure form and investigated by means of circular dichroism (CD) spectroscopy, both in electronic and vibrational range (ECD, VCD), in combination with quantum chemical calculations. For compound 2, the X-ray structure was available; thus, the ECD in the solid sta...


    pub_type: 杂志文章


    authors: Górecki M,Capozzi MAM,Albano G,Cardellicchio C,Di Bari L,Pescitelli G

    更新日期:2018-01-01 00:00:00

  • Headspace gas chromatography-mass spectrometry analysis of isoflurane enantiomers in blood samples after anesthesia with the racemic mixture.

    abstract::Several in vivo and in vitro studies on the stereoselective potency of isoflurane enantiomers suggest beneficial effects of the (+)-(S)-enantiomer. In order to detect possible differences in the pharmacokinetics of isoflurane enantiomers, a clinical study of 41 patients undergoing general anesthesia maintained with ra...


    pub_type: 临床试验,杂志文章


    authors: Schmidt R,Wahl HG,Häberle H,Dieterich HJ,Schurig V

    更新日期:1999-01-01 00:00:00

  • Enantioselective Friedel-Crafts reaction of indoles with trifluoroacetaldehyde catalyzed by Cinchona alkaloids.

    abstract::The first direct asymmetric synthetic preparation of trifluoro-1-(indol-3-yl)ethanols (TFIEs) is described by an enantioselective organocatalytic method from indoles and inexpensive trifluoroacetaldehyde methyl hemiacetal. The reaction is catalyzed by hydroquinine to produce TFIEs in an almost quantitative yield and w...


    pub_type: 杂志文章


    authors: Borkin DA,Landge SM,Török B

    更新日期:2011-09-01 00:00:00

  • Time-resolved circular dichroism in carbonmonoxy-myoglobin: the central role of the proximal histidine.

    abstract::A calculation of the circular dichroism (CD) spectra of carbonmonoxy- and deoxy-myoglobin is carried out in relation to a time-resolved CD experiment. This calculation allows us to assign a dominant role to the proximal histidine in the definition of the electronic normal modes and to interpret the transient CD struct...


    pub_type: 杂志文章


    authors: Dartigalongue T,Hache F

    更新日期:2006-05-05 00:00:00

  • Enantioselective separation of 1,4-disubstituted piperazine derivatives on two cellulose chiralcel OD and OJ and one amylose chiralpak AD chiral selectors

    abstract::A series of 1,4-disubstituted piperazine derivatives with hypnotic activity were examined on three polysaccharide-based chiral stationary phases, namely, Chiracel OD, Chiracel OJ and Chiralpak AD. It was possible to resolve all the compounds on all the phases examined (1.13


    pub_type: 杂志文章


    authors: Chilmonczyk Z,Ksycinska H,Mazgajska M,Aboul-Enein HY

    更新日期:1999-01-01 00:00:00

  • Chemoenzymatic approach to optically active 4-hydroxy-5-alkylcyclopent-2-en-1-one derivatives: an application of a combined circular dichroism spectroscopy and DFT calculations to assignment of absolute configuration.

    abstract::A series of representative optically active derivatives of 4-hydroxy-5-alkylcyclopent-2-en-1-one were prepared from the respective 2-furyl methyl carbinols via the Piancatelli rearrangement followed by the enzymatic kinetic resolution of racemates. Applicability of chiroptical methods (experimental and calculated elec...


    pub_type: 杂志文章


    authors: Frelek J,Karchier M,Madej D,Michalak K,Różański P,Wicha J

    更新日期:2014-06-01 00:00:00

  • Copper(II) complexes of N2-alkyl-(S)-amino acid amides as chiral selectors for dynamically coated chiral stationary phases in RP-HPLC.

    abstract::Copper(II) complexes of N2-octyl-(S)-phenylalaninamide (Noc-Phe-NH2), N2-dodecyl-(S)-phenylalaninamide (Ndo-Phe-NH2), and N2-octyl-(S)-norleucinamide (Noc-NLeu-NH2), dynamically adsorbed on a reversed-phase C18 column, were able to perform the direct enantiomeric separation of unmodified amino acids, amino acid amides...


    pub_type: 杂志文章


    authors: Galaverna G,Corradini R,Dossena A,Marchelli R,Dallavalle F

    更新日期:1996-01-01 00:00:00

  • Stereoselective metabolism of benalaxyl in liver microsomes from rat and rabbit.

    abstract::Benalaxyl (BX), methyl-N-phenylacetyl-N-2,6-xylyl alaninate, is a potent acylanilide fungicide and consist of a pair of enantiomers. The stereoselective metabolism of BX was investigated in rat and rabbit microsomes in vitro. The degradation kinetics and the enantiomer fraction (EF) were determined using normal high-p...


    pub_type: 杂志文章


    authors: Zhang P,Zhu W,Dang Z,Shen Z,Xu X,Huang L,Zhou Z

    更新日期:2011-02-01 00:00:00