Search results for "stereo"

showing 10 items of 6147 documents

Organocatalytic Oxa-Michael/Michael/Michael/Aldol Condensation Quadruple Domino Sequence : Asymmetric Synthesis of Tricyclic Chromanes

2018

An efficient and highly stereoselective one-pot, four-component synthesis of functionalized tricyclic chromanes has been achieved through an organocatalyzed quadruple domino reaction. The reaction sequence involves an oxa-Michael/Michael/Michael/aldol condensation between alcohols, 2 equiv of acrolein, and nitrochromenes to generate the pharmaceutically important tricyclic chromanes bearing three contiguous stereogenic centers including a chiral tetrasubstituted carbon center in good domino yields (30–70%) and excellent diastereo- and enantioselectivities (>20:1 dr and >99% ee). peerReviewed

synthesisalkoholit (yhdisteet)natural productsStereochemistryasymmetric synthesisluonnontuotteet010402 general chemistry01 natural sciencesBiochemistryDominoStereocenterchemistry.chemical_compoundCascade reactionsynteesiPhysical and Theoretical Chemistryta116chemistry.chemical_classification010405 organic chemistryOrganic ChemistryAcroleindomino reactionsEnantioselective synthesistricyclic chromanes0104 chemical scienceschemistryalcohols (organic compounds)asymmetriaAldol condensationStereoselectivityasymmetryTricyclic
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Synthesis and Structure-Affinity Relationships of Spirocyclic Benzopyrans with Exocyclic Amino Moiety

2019

σ1 and/or σ2 receptors play a crucial role in pathological conditions such as pain, neurodegenerative disorders, and cancer. A set of spirocyclic cyclohexanes with diverse O-heterocycles and amino moieties (general structure III) was prepared and pharmacologically evaluated. In structure-activity relationships studies, the σ1 receptor affinity and σ1:σ2 selectivity were correlated with the stereochemistry, the kind and substitution pattern of the O-heterocycle, and the substituents at the exocyclic amino moiety. cis-configured 2-benzopyran cis-11b bearing a methoxy group and a tertiary cyclohexylmethylamino moiety showed the highest σ1 affinity ( Ki = 1.9 nM) of this series of compounds. In…

synthesisexocyclic amino moietyReceptors Opioid mudocking studieCrystallography X-RayLigands01 natural sciencesopioid receptorschemistry.chemical_compoundProtein structureDrug DiscoveryMoiety0303 health sciencesσ1 receptor ligandsstructure (σ1) affinity relationshipmolecular dynamicBenzyl groupMolecular MedicinesynthesiBenzopyransSelectivityHydrophobic and Hydrophilic Interactionsfree binding enthalpyStereochemistrychange of receptor profileMolecular Dynamics Simulation03 medical and health sciencesStructure-Activity Relationshipσ1 receptor ligands; spirocyclic compounds; benzopyrans; benzofurans; exocyclic amino moiety; synthesis; structure (σ1) affinity relationships; σ1 antagonistic activity; receptor selectivity; molecular dynamics; docking studies; free binding enthalpy; X-ray crystal structure; opioid receptors; MOR affinity; change of receptor profile; structure MOR affinity relationshipsstructure (σ1) affinity relationshipsStructure–activity relationshipHumansReceptors sigmaBenzopyransSpiro Compoundsspirocyclic compoundBinding siteMOR affinity030304 developmental biologybenzopyranbenzofuransσ1 receptor ligandBinding Sitesspirocyclic compoundsreceptor selectivitystructure MOR affinity relationshipsdocking studiesbenzofuranopioid receptorX-ray crystal structuremolecular dynamics0104 chemical sciencesProtein Structure Tertiary010404 medicinal & biomolecular chemistrychemistrySalt bridgeσ1 antagonistic activity
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Stereotaktisten annossuunnitelmien verifiointi Compass-järjestelmällä

2016

sädehoitostereotaktinen sädehoitoalgoritmitlaskentamallitVMATstereotactic radiotherapyalgorithmsradiotherapy
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Total Structure and Electronic Structure Analysis of Doped Thiolated Silver [MAg24(SR)18]2– (M = Pd, Pt) Clusters

2015

With the incorporation of Pd or Pt atoms, thiolated Ag-rich 25-metal-atom nanoclusters were successfully prepared and structurally characterized for the first time. With a composition of [PdAg24(SR)18](2-) or [PtAg24(SR)18](2-), the obtained 25-metal-atom nanoclusters have a metal framework structure similar to that of widely investigated Au25(SR)18. In both clusters, a M@Ag12 (M = Pd, Pt) core is capped by six distorted dimeric -RS-Ag-SR-Ag-SR- units. However, the silver-thiolate overlayer gives rise to a geometric chirality at variance to Au25(SR)18. The effect of doping on the electronic structure was studied through measured optical absorption spectra and ab initio analysis. This work d…

ta114ChemistryStereochemistryDopingAb initioGeneral ChemistryElectronic structureengineering.materialpalladiumBiochemistryCatalysissilver nanoclustersNanoclustersCatalysisOverlayerCrystallographyColloid and Surface ChemistryengineeringNoble metalplatinumChirality (chemistry)ta116thiolsJournal of the American Chemical Society
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Evidence of Weak Halogen Bonding: New Insights on Itraconazole and its Succinic Acid Cocrystal

2012

Exact knowledge of the crystal structure of drugs and lead compounds plays a significant role in the fields of crystal engineering, docking, computational modeling (drug–receptor interactions), and rational design of potent drugs in pharmaceutical chemistry. The succinic acid cocrystal of the systemic antifungal drug, itraconazole, reported by Remenar et al. (J. Am. Chem. Soc.2003, 125, 8456–8457) (CSD: IKEQEU), represents one of the classical examples displaying a molecular fitting mechanism in the solid state. In this work, we disclose the X-ray single-crystal structure of the cis-itraconazole–succinic acid (2:1) cocrystal and found that it differs slightly from the previously reported st…

ta214Halogen bondta114Stereochemistryta221Rational designAntifungal drugGeneral ChemistryCondensed Matter PhysicsCrystal engineeringCocrystalCocrystalchemistry.chemical_compoundsymbols.namesakechemistrySuccinic acidDocking (molecular)symbolsGeneral Materials ScienceHalogen bondingItraconazolevan der Waals forceta116ta218Crystal Growth & Design
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Matteo Carnilivari

2007

tardogotico stereotomia SiciliaSettore ICAR/18 - Storia Dell'Architettura
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Gender Stereotypes Limit Women’s Opportunities in Working Life in India

2022

tasa-arvonaisetsukupuoliroolitIntiaIndiatyöelämästereotypiat
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"Ronja rider och Steffan skejtar" : jämställdhet och framställningar av könen i Klick 7 och i Hallonbåt 1-2

2017

Tämän kandidaatintutkielman tarkoituksena on selvittää, miten sukupuolet ovat edustettuina kahdessa ruotsin kielen oppikirjassa, Klick 7:ssä ja Hallonbåt 1–2:ssa. Tietoisuus sukupuolten välisestä tasa-arvosta on lisääntynyt yhteiskunnassa ja tässä tutkimuksessa pyritään selvittämään, onko se yhdessä opetussuunnitelmien muutosten kanssa vaikuttanut oppikirjojen sisältöön sukupuolten välisen tasa-arvon ja sukupuoliin liittetävien stereotypioiden osalta. Tutkielma on toteutettu sekä laadullisena että määrällisenä sisällönanalyysina. Tutkimusmateriaalina ovat oppikirjat Klick 7 ja Hallonbåt 1–2. Tutkielmassani selvitän, miten sukupuolten välinen tasa-arvo ilmenee oppikirjoissa tarkastelemalla s…

tasa-arvosukupuoliroolikvalitatiivinen sisällönanalyysioppikirjastereotypiakvantitatiivinen sisäl-lönanalyysisukupuolistereotypiasukupuoli
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Tautību stereotipu saistība ar uztverto ģeogrāfisko attālumu

2015

Šī pētījuma mērķis ir noskaidrot vai pastāv saistība starp tautības stereotipiem un ģeogrāfisko attālumu. Šī darba izvirzītās hipotēzes pieņem, ka stereotipu piedēvējums par tuvāk dzīvojošajām tautām ir homogēnāks nekā par tālāk dzīvojošām tautām, un otrā hipotēze pieņem, ka par ģeogrāfiski tuvākām tautām pārliecība par sniegtajām stereotipiskajām īpašībām un tautu raksturojošajām pazīmēm ir augstāka. Šajā pētījumā piedalījās 100 Latvijā dzīvojoši cilvēki no kuriem 58 bija sievietes un 42 vīrieši. Vidējais vecums respondentiem bija 34 gadi (15 – 66 gadi). Pētījumā tika izmantota oriģināla aptauja pēc kuras ir iespējams noteikt tautību stereotipu – stereotipisko īpašību un stereotipisko pazī…

tautapārliecībaetniskie stereotipistereotipiPsiholoģija
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TECNICHE COSTRUTTIVE NEL MEDITERRANEO DALLA STEREOTOMIA AI CRITERI ANTISISMICI

2016

Il volume raccoglie una serie di saggi relativi alle architetture del bacino mediterraneo, rientranti in quattro aree tematiche tra loro strettamente interconnesse relative alla stereotomia, agli scambi e trasferimenti tecnologici, alle tecniche antisismiche e, infine, alla storiografia. Lo studio della tradizione costruttiva in pietra, della quale sono esaminati esempi significativi e indagate le connessioni, le influenze, le modalità di circolazione di idee è volta anche alla ricerca delle modalità di trasmissione di saperi costruttivi e di innovazioni tecnologiche nell’ambito dei cantieri. I temi legati all'utilizzo di tecniche specificamente antisismiche sono approfonditi in relazione a…

tecniche antisismichestoriografiastoriografia trasferimenti tecnologicistereotomia; tecniche antisismiche; storiografia trasferimenti tecnologicitrasferimenti tecnologicistereotomia; tecniche antisismiche; storiografia; trasferimenti tecnologicistereotomiaSettore ICAR/18 - Storia Dell'Architettura
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