0000000000008031

AUTHOR

José A. Sáez

showing 35 related works from this author

A DFT study for the regioselective 1,3-dipolar cycloadditions of nitrile N-oxides toward alkynylboronates

2003

Abstract The mechanism for the 1,3-dipolar cycloaddition of benzonitrile oxide toward ethynyl and propynylboronate has been studied by using density functional theory (DFT) at B3LYP/6-31G* level. These cycloadditions are concerted [3+2] processes. The presence of the two oxygens on the boronic ester precludes the participation of the boron atom on [3+3] processes. The two regioisomeric channels associated to the formation of the isoxazoles bearing the boronic ester unit on the 4- or 5-positions have been characterized. The B3LYP/6-31G* activation parameters are in acceptable agreement with the experiments, allowing to explain the factors controlling these regioselective cycloadditions.

NitrileStereochemistryOrganic ChemistryOxideRegioselectivityBoron atomBiochemistryMedicinal chemistryCycloadditionchemistry.chemical_compoundDipoleBenzonitrilechemistryDrug DiscoveryDensity functional theoryTetrahedron
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A DFT study for the formation of imidazo[1,2-c]pyrimidines through an intramolecular Michael addition

2006

The formation of imidazo[1,2-c]pyrimidines through a ring closure of 2-(2-sulfonylimino-1,2-dihydro-1-pyrimidinyl) acetamides has been studied using DFT methods. Analysis of the energy results for the cyclization step shows the demand of almost an acid catalyst, which increases the electrophilicity of the dihydropyrimidine moiety, in order to make feasible the intramolecular Michael addition. The substitution on both dihydropyrimidine and amide moieties has also an influence on the cyclization step.

chemistry.chemical_compoundChemistryStereochemistryIntramolecular forceAmideOrganic ChemistryDrug DiscoveryElectrophileMichael reactionMoietyRing (chemistry)BiochemistryCatalysisTetrahedron
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¿Pueden los animales ser titulares de derechos? Algunos argumentos desde una teoría garantista del Derecho

2012

Este trabajo es el resultado de una preocupada reflexión acerca de la situación ambiental que toma las controversias a propósito de los derechos de los animales como punto de partida. En primer lugar se realizan algunas consideraciones preliminares acerca de la mirada antropocéntrica que impregna la cultura jurídica en la que a diario se mueven los juristas. A continuación se analizan seis argumentos que con frecuencia han sido presentados por quienes, desde diferentes perspectivas, consideran que los animales no pueden o no deben ser titulares de derechos. Se pretende demostrar que, desde el punto de vista de la Teoría del Derecho, tales argumentos no serían suficientes para afirmar que lo…

EcologyManagement Monitoring Policy and LawEnvironmental Science (miscellaneous)LawDerechos de los animales; teoría del Derecho; garantismo; justicia globalRevista Catalana de Dret Ambiental
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Experimental and theoretical study on the substitution reactions of aryl 2,4-dinitrophenyl carbonates with quinuclidines

2006

Abstract The reactions of quinuclidines with phenyl, 4-methylphenyl, and 4-chlorophenyl 2,4-dinitrophenyl carbonates are kinetically evaluated in aqueous solution. The Bronsted-type plots (log kN vs pKa of quinuclidinium ions) are linear. The magnitude of the slopes and validated theoretical scales of electrophilicity and nucleophilicity confirm the concerted nature of these reactions.

Substitution reactionReaction mechanismAqueous solutionArylOrganic ChemistryPhotochemistryBiochemistryIonchemistry.chemical_compoundchemistryNucleophileComputational chemistryDrug DiscoveryElectrophileDinitrophenylTetrahedron
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Understanding the Participation of Quadricyclane as Nucleophile in Polar [2σ + 2σ + 2π] Cycloadditions toward Electrophilic π Molecules

2008

The formal [2sigma + 2sigma + 2pi] cycloaddition of quadricyclane, 1, with dimethyl azodicarboxylate, 2, in water has been studied using DFT methods at the B3LYP/6-31G** and MPWB1K/6-31G** levels. In the gas phase, the reaction of 1 with 2 has a two-stage mechanism with a large polar character and an activation barrier of 23.2 kcal/mol. Inclusion of water through a combined discrete-continuum model changes the mechanism to a two-step model where the first nucleophilic attack of 1 to 2 is the rate-limiting step with an activation barrier of 14.7 kcal/mol. Analysis of the electronic structure of the transition state structures points out the large zwitterionic character of these species. A DF…

Reaction ratechemistry.chemical_compoundReaction mechanismchemistryNucleophileComputational chemistryStereochemistryZwitterionOrganic ChemistryElectrophileQuadricyclaneSolvent effectsCycloadditionThe Journal of Organic Chemistry
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A combined experimental and theoretical study of the polar [3+2] cycloaddition of electrophilically activated carbonyl ylides with aldehydes and imin…

2009

International audience; Numerous 2,5-diaryl-1,3-dioxolane-4,4-dicarbonitriles and 2,4-diphenyl-1,3-oxazolidine-5,5- dicarbonitriles have been synthesized by [3+2] cycloaddition reactions between carbonyl ylides generated from epoxides, and aldehydes or imines. In contrast to the use of aldehydes (3,4,5- trimethoxybenzaldehyde, piperonal, 1-naphthaldehyde, indole-3-carboxaldehyde, furan-2- carboxaldehyde and thiophene-2-carboxaldehyde), the reactions performed with imines (N- (phenylmethylene)methanamine, N-(1,3-benzodioxol-5-ylmethylene)propylamine, N-(1,3-benzodioxol- 5-ylmethylene)butylamine and N-(1,3-benzodioxol-5-ylmethylene)benzylamine) proceed diastereoselectively. The effect of micr…

chemistry.chemical_classification010405 organic chemistry[CHIM.ORGA]Chemical Sciences/Organic chemistryOrganic ChemistryIminePropylamine010402 general chemistry01 natural sciencesAldehydeMedicinal chemistryCycloaddition0104 chemical scienceschemistry.chemical_compoundPiperonalBenzylaminechemistryNucleophileYlideOrganic chemistry
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Maquiavelos senza virtú: a propósito de las realidades del realismo político

2019

Hans J. Morgenthau es uno de los autores más representativos del realismo en las relaciones internacionales. Su obra, sin embargo, ha sido recibida en España y otros países de forma un tanto sesgada, descuidando fundamentalmente aquellos elementos de su teoría que guardan relación con la moral. Este trabajo da cuenta de los elementos comunes a los autores del realismo clásico del siglo XX. A continuación, se profundiza en las particularidades del realismo de Morgenthau y se apuntan algunos sus principales desarrollos e influencias contemporáneas.

International relationsWork (electrical)Dret internacionalRelacions internacionalsGeneral MedicineSociologyDret FilosofiaCiències polítiques FilosofiaRealismEpistemology
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An ELF analysis of the C–C bond formation step in the N-heterocyclic carbene-catalyzed hydroacylation of unactivated C–C double bonds

2012

The changes in electron-density along the C–C bond-formation step in the N-heterocyclic carbene-catalyzed hydroacylation of unactivated double bonds has been studied by an electron localization function (ELF) analysis at the B3LYP/6-31G** level in order to characterize the reaction mechanism. Analysis of DFT reactivity indices and the natural bond orbital and ELF analysis at the most relevant points of the intrinsic reaction coordinate indicate that the reaction path takes place through a two-stage one-step mechanism with non-polar character. In the first stage a hydrogen atom is transferred from the hydroxyl group of Breslow intermediate 12 to the terminal olefinic carbon atom, to yield a …

chemistry.chemical_classificationReaction mechanismDouble bondStereochemistryGeneral Chemical EngineeringStetter reactionHydroacylationGeneral Chemistrychemistry.chemical_compoundchemistryIntramolecular forceReactivity (chemistry)CarbeneNatural bond orbitalRSC Advances
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Formation of Pyrazol-1,3,4-Thiadiazoles through 1,3-Dipolar Cycloadditions of 3-Thioxo-[1,2,4]-Triazepin-5-one with Nitrilimines: An Experimental and…

2009

In this work the results of experimental and computational study of the title compounds and some ancillary compounds are reported. Two bicyclic pyrazol-1,3,4-thiadiazole derivatives were synthesized by reaction between 6-dimethylaminomethylene-3-thioxo-[1,2,4]- triazepin-5-one 1 and several nitrilimines 2a-f to give corresponding spirocycloadducts 3a-f, which undergo a rapid rearrangement leading to the new bicyclic compounds, 4a-f and 5a-f. These obtained bicyclic products were characterized by 1H and 13C NMR spectroscopy and finally by X-ray crystallography. Theoretical calculations have been carried out using DFT methods to rationalize the formation of the two new bicyclic compounds. Two…

Bicyclic moleculeStereochemistryChemistryOrganic ChemistryAncillary compoundsRegioselectivityCarbon-13 NMRRing (chemistry)Cleavage (embryo)CycloadditionCatalysisThiadiazolesComputational chemistryPhysical and Theoretical Chemistry
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Understanding the Mechanism of the Intramolecular Stetter Reaction. A DFT Study

2012

The mechanism of the N-heterocyclic carbene (NHC)-catalyzed intramolecular Stetter reaction of salicylaldehyde 1 to yield chromanone 3 has been theoretically studied at the B3LYP/6-31G** level. This NHC-catalyzed reaction takes place through six elementary steps, which involve: (i) formation of the Breslow intermediate IN2; (ii) an intramolecular Michael-Type addition in IN2 to form the new C-C s bond; and (iii) extrusion of the NHC catalyst from the Michael adduct to yield chromanone 3. Analysis of the relative free energies in toluene indicates that while formation of Breslow intermediate IN2 involves the rate-determining step of the catalytic process, the intramolecular Michael-type addi…

Models MolecularStereochemistryPharmaceutical Scienceintramolecular Stetter reactionDFT calculationsArticleCatalysisAnalytical ChemistryStereocenterCatalysislcsh:QD241-441chemistry.chemical_compoundlcsh:Organic chemistryComputational chemistryHeterocyclic CompoundsDrug Discoveryintramolecular Michael additionorganocatalysisN-heterocyclic carbenesPhysical and Theoretical ChemistrymechanismsChemistryOrganic ChemistryStetter reactionorganocatalysis; <em>N</em>-heterocyclic carbenes; <em>umpolung</em> reactivity; intramolecular Stetter reaction; intramolecular Michael addition; mechanisms; DFT calculationsSalicylaldehydeChemistry (miscellaneous)Yield (chemistry)OrganocatalysisIntramolecular forceumpolung reactivityMolecular MedicineCarbeneMethaneMolecules
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Toward an understanding of the 1,3-dipolar cycloaddition between diphenylnitrone and a maleimide:bisamide complex. A DFT analysis of the reactivity o…

2007

Abstract The 1,3-dipolar cycloaddition between diphenylnitrone and a maleimide:bisamide complex has been studied using density functional theory (DFT) methods at the B3LYP/6-31G∗ level. The molecular recognition of the bisamide receptor to maleimide favors the formation of the complex through three hydrogen bonds. However, they are not able to produce an efficient acceleration of the cycloaddition because the symmetric substitution of the dipolarophile sites. This poor capability is discussed in base of the transition state structures and the analysis of the reactivity indexes of the reagents.

Hydrogen bondCondensed Matter PhysicsBiochemistryCycloadditionchemistry.chemical_compoundMolecular recognitionchemistryComputational chemistryReagent13-Dipolar cycloadditionReactivity (chemistry)Density functional theoryPhysical and Theoretical ChemistryMaleimideJournal of Molecular Structure: THEOCHEM
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Experimental and theoretical study of the [3+2] cycloaddition of carbonyl ylides with alkynes

2012

[EN] The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and alkynes (phenylacetylene, methyl propiolate, methyl but-2-ynoate and methyl 3-phenylpropiolate) to give substituted 2,5-dihydrofurans was investigated. The effect of indium(III) chloride on the outcome of the reaction was studied in the case of phenylacetylene and methyl propiolate. The thermal reaction between the carbonyl ylide coming from 2,2-dicyano-3-phenyloxirane and both methyl propiolate and methyl but-2-ynoate was theoretically investigated using DFT methods in order to explain the reactivity and regioselectivity observed.

chemistry.chemical_classification010405 organic chemistryMethyl propiolate[CHIM.ORGA]Chemical Sciences/Organic chemistryOrganic Chemistrychemistry.chemical_elementRegioselectivity010402 general chemistryPhotochemistry01 natural sciencesBiochemistryChlorideMedicinal chemistryCycloaddition0104 chemical scienceschemistry.chemical_compoundchemistryPhenylacetyleneYlidemedicineReactivity (chemistry)Physical and Theoretical ChemistryIndiummedicine.drug
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Diels-Alderase Catalyzing the Cyclization Step in the Biosynthesis of Spinosyn A

2015

The conversion of putative macrocyclic lactone into the tricyclic compound, as a key step in the biosynthesis of spinosyn A , has been theoretically investigated using DFT methods. The relatively low activation free energy computed for the cyclization process of the actual macrocyclic lactone (21.0 kcal/mol) furnishes a rationalization for a spontaneous ( i.e. nonenzymatically catalyzed) cyclization process in the biosynthesis of spinosyn A . A geometric analysis of putative macrocyclic lactone indicates that a slight strain on the lactone at the active site of the SpnF gene could decrease the activation free energy to ca . 16 kcal/mol. This nonspecific participation of the enzyme, which ac…

chemistry.chemical_classificationStrain (chemistry)biologyStereochemistryActive siteCatalysisEnzyme catalysischemistry.chemical_compoundEnzymeBiosynthesischemistrybiology.proteinLactoneDiels–Alder reaction
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Lewis acid induced [4+3] cycloadditions of 2-silyloxyacroleins. Insights on the mechanism from a DFT analysis

2005

The mechanism for the Lewis acid induced [4+3] cycloadditions of 2-(trimethylsilyloxy)acrolein with furan has been examined here through DFT calculations at B3LYP/6-31G* level. The mechanism is a three-step process initialized by the nucleophilic attack of furan to the β-conjugated position of acrolein yielding a zwitterionic intermediate. The key step on the formation of the seven-membered ring is the electrophilic attack of the furan residue to the carbonyl carbon in this intermediate. The endo selectivity experimentally observed is reproduced by the calculations.

Reaction mechanismStereochemistryOrganic ChemistryAcroleinBiochemistryResidue (chemistry)chemistry.chemical_compoundchemistryNucleophileComputational chemistryFuranDrug DiscoveryElectrophileLewis acids and basesSelectivityTetrahedron
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Toward an understanding of the acceleration of Diels-Alder reactions by a pseudo-intramolecular process achieved by molecular recognition. A DFT stud…

2007

The pseudo-intramolecular Diels−Alder (DA) reaction between a 2-substituted furan (1) and a N-maleimide derivative (2) has been analyzed using DFT methods. Formation of two hydrogen bonds between the appendages on furan and maleimide derivatives favors thermodynamically the formation of a molecular complex (MC1) through an efficient molecular recognition process. The large enthalpy stabilization associated with the molecular recognition overcomes the unfavorable activation entropy associated with the bimolecular process. As a consequence, the subsequent DA reaction is clearly accelerated through a pseudo-intramolecular process.

chemistry.chemical_compoundMolecular recognitionchemistryIntramolecular reactionHydrogen bondFuranIntramolecular forceOrganic ChemistryEnthalpyImidePhotochemistryMaleimideThe Journal of organic chemistry
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Experimental and theoretical investigations for the tandem alkylation–isomerization reactions between unsaturated carboxylic acids and allyl halides

2003

Abstract—Alkylation of dienediolates from unsaturated carboxylic acids with allylic halides when followed by solventless thermaltreatment at 150 to 2008C afford rearranged products on a trend highly dependent on the acarbon substitution. Thus, 2,2-bisallylated acidswith H atoms at C-2 lead to its 1,3-shift, whereas 2-methyl-2,2-bisallylated acids lead to the corresponding Cope rearrangement product. Inthe latter case, this tandem allylation-Cope reaction lead, in a highly regio and diastereoselective way, to products not accessible from directalkylation. B3LYP/6-31G p energies for the compounds involved at these isomerizations are in reasonable agreement with the experiments,allowing to exp…

Steric effectsAllylic rearrangementChemistryOrganic ChemistryDrug DiscoveryElectrophileRegioselectivityOrganic chemistryReactivity (chemistry)AlkylationBiochemistryIsomerizationCope rearrangementTetrahedron
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Polar [3 + 2] cycloaddition of ketones with electrophilically activated carbonyl ylides. Synthesis of spirocyclic dioxolane indolinones

2008

International audience; The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and ketones (ethyl pyruvate, ethyl phenylglyoxylate, isatin, N-methylisatin and 5-chloroisatin) to give substituted dioxolanes and spirocyclic dioxolane indolinones was investigated. The effect of microwave irradiation on the outcome of the reaction was studied. The thermal reaction between 2,2-dicyano-3-phenyloxirane and N-methylisatin was theoretically studied using DFT methods. This reaction is a domino process that comprises two steps. The first is the thermal ring opening of the epoxide to yield a carbonyl ylide intermediate, whereas the second step is a polar [3 + 2] cycloadditio…

chemistry.chemical_classification[CHIM.ORGA]Chemical Sciences/Organic chemistry010405 organic chemistryOrganic ChemistryEpoxide010402 general chemistry01 natural sciencesBiochemistryCycloaddition0104 chemical scienceschemistry.chemical_compoundchemistryYlideDioxolaneYield (chemistry)ElectrophileOrganic chemistryStereoselectivityPhysical and Theoretical ChemistryChemoselectivityComputingMilieux_MISCELLANEOUSOrganic &amp; Biomolecular Chemistry
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Lewis Acid-Catalyzed [4 + 3] Cycloaddition of 2-(Trimethyl Silyloxy)acrolein with Furan. Insight on the Nature of the Mechanism from a DFT Analysis

2003

[reaction: see text]. The mechanism for the Lewis acid-catalyzed [4 + 3] cycloaddition of 2-(trimethylsilyloxy)acrolein 1 with furan 2 has been studied at the B3LYP/6-31G level. This reaction is a three-step process that is initialized by the nucleophilic attack of 2 to the beta-conjugated position of 1 to give a zwitterionic intermediate IN1. The key step on the formation of the seven-membered ring is the electrophilic attack of the furan residue to the electrophilically activated carbonyl carbon at this intermediate.

StereochemistryOrganic ChemistryAcroleinBiochemistryMedicinal chemistryCycloadditionCatalysischemistry.chemical_compoundResidue (chemistry)chemistryNucleophileFuranElectrophileLewis acids and basesPhysical and Theoretical ChemistryOrganic Letters
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Hans J. Morgenthau´s Turn from International Law to International Relations: A transition affected by History

2018

Este texto aborda el papel que las consideraciones históricas desempeñaron en un movimiento teórico sustancial: el paso que a partir de los años cuarenta se produce desde el Derecho Internacional a las Relaciones Internacionales en tanto que principal disciplina ordenadora del ámbito interestatal. Se tomará a Hans J. Morgenthau como el ejemplo más claro de este movimiento. Al igual que tantos otros intelectuales europeos exiliados en Estados Unidos, el cambio de continente y de contexto académico implicará para Morgenthau el salto del estudio del Derecho al estudio de la Política. Para explicar este movimiento y, en concreto, el peso que la Historia tiene en él, se estructurará el artículo …

Realismo político060106 history of social scienceslcsh:Political scienceHans J. MorgenthauLegal sciencePoliticsPolitical science050602 political science & public administrationHistoricism0601 history and archaeologyDret FilosofiaFilosofía del Derecho Inter-nacionalOrder (virtue)International relationsHistoria de la ideasDret internacionalPower politicsDerechoRelacions internacionals05 social scienceslcsh:International relations06 humanities and the artsGeneral MedicineInternational lawhistoria de las ideas políticasRelaciones Internacionales0506 political sciencefilosofía del derecho internacionalCriticismHumanitieslcsh:Jlcsh:JZ2-6530
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DFT Study of the Molecular Mechanism of Lewis Acid Induced [4 + 3] Cycloadditions of 2-Alkylacroleins with Cyclopentadiene

2009

The mechanism of the Lewis acid (AlCl(3)) induced [4 + 3] cycloaddition of 2-methylacrolein with cyclopentadiene (Cp) [ J. Am. Chem. Soc. 2004, 126, 2692] has been examined here through DFT calculations at the MPW1K(DCM)/6-31+G** level. Formation of these seven-membered carbocycles is a domino process that comprises three consecutive reactions. The first one is a polar Diels-Alder reaction that is initialized by the nucleophilic attack of Cp to the beta-conjugated position of acrolein, yielding the formation of the endo and exo [4 + 2] cycloadducts. The corresponding LA-[4 + 2] cycloadduct complexes equilibrate through a skeleton rearrangement with a low free activation energy with two seve…

chemistry.chemical_compoundReaction mechanismCyclopentadieneNucleophileIntramolecular reactionChemistryHydrideStereochemistryIntramolecular forceOrganic ChemistryLewis acids and basesCycloadditionThe Journal of Organic Chemistry
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Origin of the synchronicity in bond formation in polar Diels-Alder reactions: an ELF analysis of the reaction between cyclopentadiene and tetracyanoe…

2012

[EN] The origin of the synchronicity in C-C bond formation in polar Diels-Alder (P-DA) reactions involving symmetrically substituted electrophilic ethylenes has been studied by an ELF analysis of the electron reorganization along the P-DA reaction of cyclopentadiene (Cp) 4 with tetracyanoethylene (TCE) 10 at the B3LYP/6-31G* level. The present study makes it possible to establish that the synchronicity in C-C bond formation in P-DA reactions is controlled by the symmetric distribution of the electron-density excess reached in the electrophile through the charge transfer process, which can be anticipated by an analysis of the spin electron-density at the corresponding radical anion. The ELF …

Pericyclic reactionEthyleneCyclopentadieneINGENIERIA MECANICAOrganic ChemistryElectronTetracyanoethylenePhotochemistryBiochemistryIonchemistry.chemical_compoundchemistryElectrophilePolarPhysical and Theoretical Chemistry
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Understanding the origin of the asynchronicity in bond-formation in polar cycloaddition reactions. A DFT study of the 1,3-dipolar cycloaddition react…

2012

The origin of the asynchronicity in bond-formation in polar cycloadditions has been studied by an ELF analysis of the electron reorganisation along the 1,3-dipolar cycloaddition of Padwa's carbonyl ylide 4 with the 1,2-benzoquinone 8. This reaction presents an unexpected asynchronous bond-formation, which is initialised through the nucleophilic attack of Padwa's carbonyl ylide on the carbonyl oxygen atom of the strongly electrophilically activated 1,2-benzoquinone. The present study allows for the establishment that along an asynchronous bond-formation, the more favourable two-center interaction begins at the most electrophilic center, which is the center with the highest spin density achie…

chemistry.chemical_classificationNucleophileChemistryYlideGeneral Chemical EngineeringElectrophile13-Dipolar cycloadditionPolarGeneral ChemistrySpin densityBond formationPhotochemistryCycloadditionRSC Adv.
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Understanding the mechanism of polar Diels–Alder reactions

2009

A good correlation between the activation energy and the polar character of Diels-Alder reactions measured as the charge transfer at the transition state structure has been found. This electronic parameter controls the reaction rate to an even greater extent than other recognized structural features. The proposed polar mechanism, which is characterized by the electrophilic/nucleophilic interactions at the transition state structure, can be easily predicted by analyzing the electrophilicity/nucleophilicity indices defined within the conceptual density functional theory. Due to the significance of the polarity of the reaction, Diels-Alder reactions should be classified as non-polar (N), polar…

Reaction rateNucleophileChemistryComputational chemistryPolarity (physics)Organic ChemistryElectrophilePolarIonic bondingDensity functional theoryActivation energyPhysical and Theoretical ChemistryBiochemistryOrganic &amp; Biomolecular Chemistry
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Azo-hydrazo conversion via [1,5]-hydrogen shifts. A combined experimental and theoretical study

2012

Abstract Azoalkenes 6e , 6g , 6h , and 8c underwent an easy azo-hydrazo conversion via a [1,5]-hydrogen shift yielding α,β-unsaturated hydrazones. The isomerization products were characterized through spectroscopic and spectrometric techniques. In order to understand the nature of the mechanism of these [1,5]-hydrogen shifts, the transition state structures of the reactions were theoretically studied at the B3LYP/6-31G(d,p) level. Substitution effects in the propenylazo system on the kinetic and thermodynamic parameters were analyzed. An electron localization function (ELF) analysis of the electronic structure of the transition state structure associated with the azo-hydrazo conversion of t…

Pericyclic reactionHydrogenChemistryOrganic Chemistrychemistry.chemical_elementElectronic structureHydrogen atomKinetic energyBiochemistryTransition stateElectron localization functionComputational chemistryDrug DiscoveryIsomerizationTetrahedron
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De Kelsen a la informática jurídica: una entrevista con Mario G. Losano

2018

Desde que su mentor, Norberto Bobbio, le encargara la traducción de la segunda edición de la Teoría pura del derecho (1960), la carrera de Mario G. Losano ha sido tan larga como polifacética. En esta entrevista, conversamos sobre su formación y sobre el contexto cultural que envolvió el inicio de su carrera académica en Italia. Posteriormente, nos centramos en dos de los principales temas de su producción académica. Por un lado, profundizamos en sus estudios kelsenianos, destacando el enfoque histórico que caracteriza su aproximación a los problemas iusfilosóficos. Y, por otro lado, abordamos el asunto de los orígenes y el desarrollo de la informática jurídica, de la cual el profesor Losano…

Academic careerCultural backgroundLegal informaticsSociologyDret FilosofiaHistorical methodEpistemologyFocus (linguistics)
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Pacifismo jurídico = Legal pacifism

2019

Resumen:  Guerra y paz pueden ser pensadas como dos momentos que estan destinados a sucederse alternativamente dentro la historia de las relaciones internacionales. Pero tambien cabe la esperanza de que a traves del desarrollo de un orden internacional fuerte pueda conseguirse una paz perpetua o, cuanto menos, duradera. A ese fin han destinado sus esfuerzos numerosos juristas cuyas obras pueden ser enmarcadas dentro del pacifismo juridico. En este texto se tratara de ordenar los rasgos caracteristicos de esta posicion, tomando como division central aquella que separa los autores que han apostado por la prohibicion de la guerra de aquellos que han apostado por su progresiva superacion. Ambas…

EUNOMÍA. Revista en Cultura de la Legalidad
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Unravelling the mechanism of the ketene-imine Staudinger reaction. An ELF quantum topological analysis

2015

The mechanism of the ketene-imine Staudinger (KI-S) reaction between t-butyl-cyano ketene and N-phenyl phenylimine has been studied using DFT methods at the MPWB1K/6-311G(d) computational level. The reaction takes place through a two-step mechanism: (i) the first step is the nucleophilic attack of the imine nitrogen lone pair on the central carbon of the ketene yielding a zwitterionic (ZW) intermediate; (ii) the second step, which is the rate- and stereoselectivity-determining step, is a ring-closure process achieved by a nucleophilic attack of the terminal carbon atom of the ketene on the imine carbon atom. Due to the unfeasibility of a cis/trans and an E/Z stereoisomerisation at the ZW in…

ChemistryStereochemistryGeneral Chemical EngineeringImineKeteneGeneral ChemistryTopologychemistry.chemical_compoundNucleophileSingle bondStaudinger reactionConrotatory and disrotatoryHOMO/LUMOLone pairRSC Advances
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A Comparative Analysis of the Electrophilicity of Organic Molecules between the Computed IPs and EAs and the HOMO and LUMO energies

2007

[EN] The electrophilicity index, omega, of a series of substituted ethylenes used in some relevant organic reactions has been evaluated from the ionization potential JP) and the electron affinity (EA) computed by vertical ionization at the B3LYP/aug-cc-PVTZ level. The corresponding electrophilicity values are well correlated with those obtained from the HOMO and LUMO energies of the neutral molecules. The good linear correlation found between omega(I,A) and omega(H,L)(LBS), and between omega(H,L)(LBS) and omega(H,L)(SBS) allows to confirm the use of the easily available B3LYP/6-31G(*) HOMO and LUMO energies to obtain reasonable values of the global electrophilicity index of organic molecule…

ChemistryBasis-SetsReactivityGeneral Physics and AstronomyScalesOrganic reactionDensity-Functional TheoryComputational chemistryHardnessIonizationElectron affinityElectrophileComputationMoleculeElectron-AffinitiesDensity functional theoryQuantitative characterizationPhysical and Theoretical ChemistryIonization energyHOMO/LUMO
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Understanding the Electronic Reorganization along the Nonpolar [3+2] Cycloaddition Reactions of Carbonyl Ylides

2011

[EN] The nonpolar [3+2] cycloaddition (32CA) reaction of the carbonyl ylide (CY) 23 with tetramethylethylene (TME) 24 has been studied with DFT methods at the B3LYP/6-31G* level. This cycloaddition reaction, which has a very low activation energy of 4.7 kcal/mol, takes place through a synchronous transition structure. A topological analysis of the ELF along the 32CA reaction provides a new scope of the electronic structure of CY 23 as a pseudodiradical species offering a sound explanation of the high reactivity of this CY in nonpolar reactions. In addition, this analysis points to the nonparticipation of the oxygen lone pairs in the 32CA reaction. This cycloaddition can be seen as a pseudod…

chemistry.chemical_classificationPericyclic reactionchemistryYlideOrganic ChemistryMoleculeReactivity (chemistry)Activation energyElectronic structurePhotochemistryLone pairCycloaddition
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1,3-Dipolar cycloadditions of electrophilically activated benzonitrile N-oxides. Polar cycloaddition versus oxime formation.

2006

The reactions of electrophilically activated benzonitrile N-oxides (BNOs) toward 3-methylenephthalimidines (MPIs) have been studied using density functional theory (DFT) at the B3LYP/6-31G* level. For these reactions, two different channels allowing the formation of the [3 + 2] cycloadducts and two isomeric (E)- and (Z)-oximes have been characterized. The 1,3-dipolar cycloadditions take place along concerted but highly asynchronous transition states, while formation of the oximes is achieved through a stepwise mechanism involving zwitterionic intermediates. Both reactions are initiated by the nucleophilic attack of the methylene carbon of the MPIs to the carbon atom of the electrophilically…

Benzonitrilechemistry.chemical_compoundchemistryNucleophileStereochemistryOrganic ChemistrySolvent effectsMethylenePhotochemistryTransition stateCycloadditionElectron localization functionNatural bond orbitalThe Journal of organic chemistry
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A combined experimental and theoretical study of the thermal cycloaddition of aryl azides with activated alkenes.

2011

International audience; Reactions were performed from aryl azides on the one hand, and activated alkenes coming from β-dicarbonyl compounds or malonodinitrile on the other hand, either with recourse to conventional heating or to microwave activation, to afford 1-aryl-1H-1,2,3-triazoles. The mechanism and the regioselectivity of the reactions involving β-dicarbonyl compounds have been theoretically studied using DFT methods at the B3LYP/6-31G* level: they are domino processes comprising a tautomeric equilibrium of the β-dicarbonyl compounds with their enol forms, a 1,3-dipolar cycloaddition of the enol forms with the aryl azides (high activation energy), and a dehydration process (lower acti…

AzidesAntifungal AgentsAntineoplastic AgentsMicrobial Sensitivity TestsActivation energyAlkenes010402 general chemistryPhotochemistry01 natural sciencesBiochemistryStructure-Activity Relationshipchemistry.chemical_compoundCell Line TumorThermalHumansPhysical and Theoretical ChemistryMicrowavesMolecular Structure010405 organic chemistry[CHIM.ORGA]Chemical Sciences/Organic chemistryArylOrganic ChemistryTemperatureRegioselectivityStereoisomerismTriazolesEnolCombinatorial chemistryTautomerCycloadditionAnti-Bacterial Agents0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistrychemistryCyclizationQuantum TheoryDegradation (geology)Drug Screening Assays Antitumor
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Toward an understanding of the unexpected regioselective hetero-Diels-Alder reactions of asymmetric tetrazines with electron-rich ethylenes: a DFT st…

2009

The regioselective hetero-Diels-Alder (HDA) reaction of asymmetric tetrazines (TTZs) with electron-rich (ER) ethylenes has been studied with use of DFT methods at the B3LYP/6-31G* level of theory. The reaction is a domino process that comprises three consecutive reactions: (i) a HDA reaction between the TTZ and the ER ethylene; (ii) a retro-Diels-Alder reaction with loss of nitrogen; and (iii) a beta-hydrogen elimination with formation of the final pyridazines. The first polar HDA reaction, which is associated to the nucleophilic attack of the ER ethylene to the electrophilically activated TTZ, is the rate and regioselectivity determining step of the domino process. The unexpected regiosele…

Computational chemistryChemistryOrganic ChemistryDiels alderRegioselectivityOrganic chemistryElectronThe Journal of organic chemistry
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Protection against chemical submission: naked-eye detection of γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages

2020

Two new oxazole derivatives, able to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages, by color and fluorescence changes, are reported.

ChromatographyMetals and AlloysGeneral ChemistryCatalysisSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry.chemical_compoundγ-Hydroxybutyric acidchemistryMaterials ChemistryCeramics and Compositessense organsNaked eyeskin and connective tissue diseasesOxazoleChemical Communications
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Filosofía del derecho internacional, violencia y masculinidad hegemónica = Philosophy of international law, violence and hegemonic masculinity

2019

RESUMEN: La violencia es considerada a menudo un elemento consustancial al ambito internacional: algo que el derecho internacional puede quiza reducir pero no eliminar completamente. Este trabajo se hace eco de las criticas feministas al derecho internacional poniendolas en relacion con los conceptos elaborados por los estudios sobre masculinidades. Que el derecho internacional sea una disciplina historicamente manejada por hombres encuentra su proyeccion sobre cinco ambitos: 1) el concepto de estado en tanto que actor principal del derecho internacional, 2) el sistema de fuentes, en particular, los tratados internacionales; 3) la aplicacion de las normas internacionales a traves de tribuna…

DerechoPolitical scienceInternational lawHumanitiesHegemonic masculinityUNIVERSITAS. Revista de Filosofía, Derecho y Política
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Heteroditopic chemosensor to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages.

2021

Drug-Facilitated Sexual Assault (DFSA) is a problem of considerable dimensions on a global scale. Among the different compounds used in DFSA assaults, 4-hydroxybutyric acid (GHB) is one of the most elusive due to its physical and biological characteristics. Therefore, the development of real-time detection methods to detect GHB not only in drinks but also in urine is very important for personal and social security. Here, we report two new heteroditopic chemosensors capable of recognizing and detecting GHB in soft drinks, alcoholic beverages and synthetic urine. The compounds have two moieties: a trifluoroacetyl group and a thiourea, which are able to interact respectively with the hydroxyl …

ChromatographyChemistryAlcoholic BeveragesHydroxybutyratesCarbonated BeveragesBiochemistryAnalytical ChemistryBeveragesSynthetic urineγ-Hydroxybutyric acidElectrochemistryEnvironmental ChemistrySodium OxybateSpectroscopySexual assaultThe Analyst
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