How do reaction conditions affect the enantiopure synthesis of 2-substituted-1,4-benzodioxane derivatives?

abstract：:Glutathione (GSH) conjugation of the chiral compound 2-bromo-3-phenylpropionic acid (BPP) was studied in vitro and in the rat in vivo. GSH conjugation of BPP, catalyzed by a mixture of glutathione-S-transferases (GST's) from rat liver cytosol in vitro, was stereoselective: at a substrate concentration of 250 microM, (...

journal_title：Chirality

authors： Snel CA,Mahadevan S,Polhuijs M,Mulder GJ

更新日期：1992-01-01 00:00:00

abstract：:Previously, a diazaphospholidine has been synthesized and evaluated as a chiral derivatizing reagent for the determination of the optical purity of chiral alcohols via 31P NMR spectroscopy (Alexakis et al., J. Org. Chem. 57:1224-1237, 1992). Our laboratory is interested in the advantageous and practical applications o...

journal_title：Chirality

authors： House KL,O'Connor MJ,Silks LA 3rd,Dunlap RB,Odom JD

更新日期：1994-01-01 00:00:00

abstract：:Novel enantiopure 1,2,4-trizole-3-thiones containing a benzensulfonamide moiety were synthesized via multistep reaction sequence starting with D-phenylalanine methyl ester and L-phenylalanine ethyl ester as a source of chirality. The chemical structures of all compounds were characterized by elemental analysis, UV, IR...

journal_title：Chirality

authors： Başaran E,Karaküçük-Iyidoğan A,Schols D,Oruç-Emre EE

更新日期：2016-06-01 00:00:00

abstract：:Compared to simulated moving bed (SMB) chromatography, fractional crystallization is a simple and economical method for enantioseparation. Therefore, the coupling of SMB chromatography and fractional crystallization is suggested for enantioseparation of racemic compounds. In this work, a nonsteroidal antiinflammatory ...

journal_title：Chirality

authors： Hong Lu Y,Bun Ching C

更新日期：2004-10-01 00:00:00

abstract：:The simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac-fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after...

journal_title：Chirality

authors： De Miranda Silva C,Marques MP,Barissa GR,Donadi EA,Da Silva LM,Lanchote VL

更新日期：2007-05-05 00:00:00

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...

journal_title：Chirality

authors： Borkin DA,Landge SM,Török B

更新日期：2011-09-01 00:00:00

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

journal_title：Chirality

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

更新日期：1999-01-01 00:00:00

abstract：:Optically active lumazines (biolumazine, dictyolumazine, monalumazine, and neolumazine) are prepared from the corresponding pterins by enzymatic reaction, using pterin deaminase excreted by Dictyostelium discoideum. The fluorescence properties, circular dichroism spectra, and chromatographic behavior of these lumazine...

journal_title：Chirality

authors： Klein R,Tatischeff I,Tham G,Mano N

更新日期：1994-01-01 00:00:00

abstract：:The possibility that enantiodiscrimination of bilirubin might be involved in neuronal membrane destabilization, and therefore in bilirubin toxicity, was investigated, by circular dichroism, on model membranes composed of phospholipids. The equilibrium between bilirubin enantiomers is displaced at some extent by the in...

journal_title：Chirality

authors： Bernardini C,D'Arrigo P,Elemento G,Mancini G,Servi S,Sorrenti A

更新日期：2009-01-01 00:00:00

abstract：:The interaction between the tetra-anionic porphyrin H2TPPS and its copper derivative, CuTPPS, with the tetra-cationic porphyrin H2T4 and its copper derivative, CuT4, leads, in aqueous solution, to the formation of remarkably stable and kinetically inert heteroaggregates. The aggregation process is under hierarchic con...

journal_title：Chirality

authors： Rosaria L,D'urso A,Mammana A,Purrello R

更新日期：2008-03-01 00:00:00

abstract：:Ropivacaine hydrochloride monohydrate (ropivacaine) is a new local anaesthetic agent which is administered exclusively as the (-)-(S)-form. The aim of the study was to determine whether metabolic racemisation of (-)-(S)-ropivacaine occurs. This was tested in man, rat, dog, and sheep after different routes of administr...

journal_title：Chirality

authors： Arvidsson T,Bruce HF,Halldin MM

更新日期：1995-01-01 00:00:00

abstract：:The attempts of applying chiroptical spectroscopy to supramolecular chirality are reviewed with a focus on vibrational circular dichroism (VCD). Examples were taken from gels, solids, and monolayers formed by low-molecular mass weight chiral gelators. Particular attention was paid to a group of gelators with perfluoro...

journal_title：Chirality

authors： Sato H,Yajima T,Yamagishi A

更新日期：2015-10-01 00:00:00

abstract：:Metoprolol is available for clinical use as a racemic mixture. The S-(-)-metoprolol enantiomer is the one expressing higher activity in the blockade of the β(1)-adrenergic receptor. The α-hydroxymetoprolol metabolite also has activity in the blockade of the β(1)-adrenergic receptor. The present study describes the dev...

journal_title：Chirality

authors： Antunes Nde J,Cavalli RC,Marques MP,Lanchote VL

更新日期：2013-01-01 00:00:00

abstract：:The electronic circular dichroism (ECD) spectra of two sesquiterpenoids (1 and 2) related to oplopanone, obtained from a methanolic extract of the plant Serphidium stenocephalum (Artemisia stenocephala), were measured and reproduced by means of time-dependent density functional theory (TDDFT) calculations, establishin...

journal_title：Chirality

authors： Shafiq N,Saleem M,Riaz N,Tousif MI,Jabbar A,Tareen RB,Pescitelli G

更新日期：2014-01-01 00:00:00

abstract：:The direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, m...

journal_title：Chirality

authors： Lei M,Xia S,Wang J,Ge Z,Cheng T,Li R

更新日期：2010-06-01 00:00:00

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...

journal_title：Chirality

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

abstract：:The separation methods of the enantiomers of two β-blockers and tryptophan were studied using capillary electrochromatography with heparin covalently as well as non-covalently, bonded onto the capillary inner wall as stationary phase and electrokinetic chromatography with heparin as pseudostationary phase. In the case...

journal_title：Chirality

authors： Liu Y,Sombra LL,Stege PW

更新日期：2018-06-25 00:00:00

abstract：:E-6087 is a nonsteroidal anti-inflammatory compound that selectively inhibits cyclooxygenase-2. Because E-6087 has a chiral center, this compound is a racemic mixture of two stereoisomers, (+)-(R)-E-6087 (E-6231) and (-)-(S)-E-6087 (E-6232). A normal-phase liquid-chromatographic method for the enantioselective determi...

journal_title：Chirality

authors： Salgado L,Encina G,Farran R,Puig S,Martínez L

更新日期：2004-05-15 00:00:00

abstract：:The optically active mixed-ligand fac(S)-tris(thiolato)rhodium(III) complexes, ΔL -fac(S)-[Rh(aet)2 (L-cys-N,S)](-) (aet = 2-aminoethanethiolate, L-cys = L-cysteinate) () and ΔLL -fac(S)-[Rh(aet)(L-cys-N,S)2 ](2-) were newly prepared by the equatorial preference of the carboxyl group in the coordinated L-cys ligand. T...

journal_title：Chirality

authors： Aizawa S,Tsubosaka S

更新日期：2016-01-01 00:00:00

abstract：:(3SR,4RS)-3,4-Epoxypiperidine-4-carboxylic acid (isoguvacine oxide) is a potent and specific GABAA receptor agonist. Isoguvacine oxide, originally designed as a potentially alkylating agonist, turned out to interact with the GABAA receptor in a fully reversible manner. The protected form of isoguvacine oxide, benzyl (...

journal_title：Chirality

authors： Frølund B,Jeppesen L,Krogsgaard-Larsen P,Hansen JJ

更新日期：1995-01-01 00:00:00

abstract：:The macrocyclic glycopeptide, ristocetin A, was covalently bonded to a silica gel support and evaluated as a liquid chromatographic (LC) chiral stationary phase (CSP). Over 230 racemates were resolved in either the reversed-phase mode, the normal-phase mode, or the polar-organic mode. The retention behavior and select...

journal_title：Chirality

authors： Ekborg-Ott KH,Liu Y,Armstrong DW

更新日期：1998-01-01 00:00:00

abstract：:The programmed assembly of p-octiphenyl rods carrying six complementary tripeptide strands was studied in the presence of bilayer membranes using circular dichroism (CD) spectroscopy. Thermal CD experiments demonstrated programmed assembly of anionic and cationic rods into supramolecules at low temperature that irreve...

journal_title：Chirality

authors： Sakai N,Matile S

更新日期：2004-01-01 00:00:00

abstract：:Three chiral derivatives of the alkaloid sparteine (bispidines), characterized by the 3,7-diazabicyclo[3.3.1]nonane moiety, were designed as efficient ligands in a number of enantioselective reactions due to their metal coordination properties. A full evaluation of the 3D properties of the compounds was carried out, a...

journal_title：Chirality

authors： Castellano C,Sacchetti A,Meneghetti F

更新日期：2016-04-01 00:00:00

abstract：:This paper reports the enantioseparation of β-hydroxy-1,2,3-triazole derivatives, which present a broad range of biological properties, by supercritical fluid chromatography (SFC) and high-performance liquid chromatography techniques (HPLC). Polysaccharide-based chiral columns (cellulose and amylose) were used to eval...

journal_title：Chirality

authors： Alvarenga N,Porto ALM,Barreiro JC

更新日期：2018-07-01 00:00:00

abstract：:In modern chromatography, chiral stationary phase (CSP) and enantiomer self-disproportionation (ESD) are new inventions of packing material offer a guarantee for a successful enantiomeric separation. All CSPs were synthesized by chemical bonding of the relevant organic moieties onto a porous parent silica material for...

journal_title：Chirality

authors： Mayani VJ,Abdi SH,Mayani SV,Kim HC,Park SK

更新日期：2011-04-01 00:00:00

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...

journal_title：Chirality

authors： Mandadapu V,Day AI,Ghanem A

更新日期：2014-11-01 00:00:00

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...

journal_title：Chirality

authors： Lynam KG,Stringham RW

更新日期：2006-01-01 00:00:00

abstract：:Chiral fungicide prothioconazole has a wide range of antifungal spectrum; however, little research has been conducted to evaluate prothioconazole on an enantiomeric level. Five target pathogens and three common aquatic organisms were tested for the enantioselective bioactivity and toxicity of prothioconazole in this w...

journal_title：Chirality

authors： Zhai W,Zhang L,Cui J,Wei Y,Wang P,Liu D,Zhou Z

更新日期：2019-06-01 00:00:00

abstract：:A series of silica-supported proline-based peptides were synthesized and applied as catalysts for direct asymmetric intermolecular aldol reactions. Among these, a peptide with two L-proline units was found to be the most efficient one for the asymmetric aldol reactions between acetone and aromatic aldehydes. The react...

journal_title：Chirality

authors： Yan J,Wang L

更新日期：2009-04-01 00:00:00

abstract：:The effects of temperature on the chiral recognition of cyclic β-amino acid enantiomers on zwitterionic [Chiralpak ZWIX(+) and ZWIX(-)] chiral stationary phases were investigated. Experiments were performed at different mobile phase compositions and under 10°C column temperature increments in the temperature range 10-...

journal_title：Chirality

authors： Ilisz I,Pataj Z,Gecse Z,Szakonyi Z,Fülöp F,Lindner W,Péter A

更新日期：2014-08-01 00:00:00