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The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such... more
The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones.
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Etude de derives de pyrazolures, triazole-1,2,4ures, tetrazolures et benzimidazolures substitues sur un carbone par triphenyl-2,4,6 pyridinio
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The synthesis and the antiparasitic evaluation of twelve new 5-nitroimidaole derivatives has been carried out. The most effective compounds were the less hydrophilic pyridinium and imidazolium salts (IV), (V) and (X), and above all the... more
The synthesis and the antiparasitic evaluation of twelve new 5-nitroimidaole derivatives has been carried out. The most effective compounds were the less hydrophilic pyridinium and imidazolium salts (IV), (V) and (X), and above all the tetrahydropyridine derivatives (XII) and (XIII).
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Un conjunt de professors de les facultats de Química i Farmàcia de la Universitat de Barcelona hem elaborat un material docent en suport electrònic, d'accés lliure a la xarxa, que descriu el procediment pràctic de diverses operacions... more
Un conjunt de professors de les facultats de Química i Farmàcia de la Universitat de Barcelona hem elaborat un material docent en suport electrònic, d'accés lliure a la xarxa, que descriu el procediment pràctic de diverses operacions bàsiques de treball al laboratori químic. L'objectiu principal és crear un material docent que serveixi de suport a l'aprenentatge dels estudiants i a
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select... more
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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ABSTRACT Abstract Imidazolium salts, which constitute a varied pool of charged chemical entities, are situated at the crossroads of multidisciplinary fields in chemistry because of their incorporation in a broad array of molecular... more
ABSTRACT Abstract Imidazolium salts, which constitute a varied pool of charged chemical entities, are situated at the crossroads of multidisciplinary fields in chemistry because of their incorporation in a broad array of molecular systems. Imidazolium functionality has emerged as a privileged structural motif for the design of specifically tailored artificial receptors for anion recognition and sensing. The specific focus of this chapter is to give an overview of these positively charged systems, with a brief discussion of the chemistry of imidazolium quaternary salts. Representative examples of imidazolium-based systems have been ordered according to their molecular frameworks and include cyclophanes, protophanes, and calixarenes as well as a tripodal molecular platform. The final section concerns miscellaneous molecular systems with a variety of coexisting topologies as well as a number of subunits, each with its own specific properties. These systems have applications in anion recognition chemistry leaning toward nanoscience. Graphical Abstract
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Skip to Main Content. ... Reviews. ChemInform Abstract: The Facets of the Heterocyclic BetainePool. Ermitas Alcalde,; Immaculada Dinares,; Neus Mesquida,; Lluisa Perez-Garcia. Article first published online: 22 MAY 2010. DOI:... more
Skip to Main Content. ... Reviews. ChemInform Abstract: The Facets of the Heterocyclic BetainePool. Ermitas Alcalde,; Immaculada Dinares,; Neus Mesquida,; Lluisa Perez-Garcia. Article first published online: 22 MAY 2010. DOI: 10.1002/chin.200217276. ...
Revisiting a '3 + 1' convergent stepwise strategy permitted the synthesis of... more
Revisiting a '3 + 1' convergent stepwise strategy permitted the synthesis of [1₄]imidazoliophane 2·2Br in excellent yield for a macrocyclization. The new [1₄]triazoliophane 3 and bis(1,2,3-triazolium) counterpart 4·2Cl were less synthetically accessible and the hybrid derivative 5·Cl proved troublesome to prepare. Triazolophane 3 was devoid of anion-binding affinities, while charged [1₄]heterophane prototypes showed a particular preference for acetate. When association constants were compared, dicationic systems 2·2PF6 and 4·2PF6 showed greater values than monocationic macrocycle 5·PF6, and the highest affinities corresponded to the bis(imidazolium) receptor 2·2PF6.
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Page 1. J. Org. Chem. 1994,59, 639-643 639 Heterocyclic Betaines. 19.' Unconventional Extended r-Systems Containing Pyridinium and Benzimidazolate Subunits. Synthesis and Characterization Ermitas Alcalde,' Immaculada ...
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... Ermitas Alcalde,*'* Immaculada DinarBs,'* Jose Elguero,lb Jean-Pierre Fayet,lc Marie-Claire Vertut,lc Carlos Miravitlles,ld and Elias ... Instituto de Quimica Mldica, CSIC, 28006-Madrid, Spain, Laboratoire de... more
... Ermitas Alcalde,*'* Immaculada DinarBs,'* Jose Elguero,lb Jean-Pierre Fayet,lc Marie-Claire Vertut,lc Carlos Miravitlles,ld and Elias ... Instituto de Quimica Mldica, CSIC, 28006-Madrid, Spain, Laboratoire de Chimie Organique Structurale, Uniuersitl Paul Sabatier, 31077-Toulouse ...
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ABSTRACT
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Abstract Empirical force field calculations (MM2 (85)) with atomic point charges calculated from AM1 calculations (MM2/AM1) correctly reproduce AM1 energy surfaces for heterocyclic betaines. The methodology allows extensive conformational... more
Abstract Empirical force field calculations (MM2 (85)) with atomic point charges calculated from AM1 calculations (MM2/AM1) correctly reproduce AM1 energy surfaces for heterocyclic betaines. The methodology allows extensive conformational analysis of medium to large ...
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The most relevant aspects of azolium(pyridinium)azolate betaines with a variety of spacers 1 is reviewed. An interdisciplinary approach to their chemistry is currently directed towards medicinal chemistry, supramolecular chemistry and... more
The most relevant aspects of azolium(pyridinium)azolate betaines with a variety of spacers 1 is reviewed. An interdisciplinary approach to their chemistry is currently directed towards medicinal chemistry, supramolecular chemistry and advanced organic materials.
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... Biochem 1972) Arzneim-Forsch 22, 1564-1569 Parasitol 12 49-60 17 Gonzalez E, Alcalde E, Dinar 1, Elguero J (1987) Bull 25 Chapman WL, Hanson ... Synth colt V, Bra MF, Roldan CM (1983) Rev Inst Med Trop Sau 13 Paulo 25, 254-260 20 Ram... more
... Biochem 1972) Arzneim-Forsch 22, 1564-1569 Parasitol 12 49-60 17 Gonzalez E, Alcalde E, Dinar 1, Elguero J (1987) Bull 25 Chapman WL, Hanson ... Synth colt V, Bra MF, Roldan CM (1983) Rev Inst Med Trop Sau 13 Paulo 25, 254-260 20 Ram S, Skinner M, Kalvin D, Wise DS ...
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IMMACULADA DINAR ÉS1, ANTONIO ENTRENA1, CARLOS JAIME1*, CRIST ´OBAL SEGURA2§ AND JOSEP FONT1 1Unitat de Quımica Org`anica, Departament de Quımica, Facultat de Ci`encies, Universitat Aut`onoma de Barcelona, 08193 Bellaterra, Spain ...
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Empirical force field calculations (MM2 (85)) with atomic point charges calculated from AM1 calculations (MM2/AM1) correctly reproduce AM1 energy surfaces for heterocyclic betaines. The methodology allows extensive conformational analysis... more
Empirical force field calculations (MM2 (85)) with atomic point charges calculated from AM1 calculations (MM2/AM1) correctly reproduce AM1 energy surfaces for heterocyclic betaines. The methodology allows extensive conformational analysis of medium to large ...
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... Ermitas Alcalde,*'* Immaculada DinarBs,'* Jose Elguero,lb Jean-Pierre Fayet,lc Marie-Claire Vertut,lc Carlos Miravitlles,ld and Elias ... Instituto de Quimica Mldica, CSIC, 28006-Madrid, Spain, Laboratoire de... more
... Ermitas Alcalde,*'* Immaculada DinarBs,'* Jose Elguero,lb Jean-Pierre Fayet,lc Marie-Claire Vertut,lc Carlos Miravitlles,ld and Elias ... Instituto de Quimica Mldica, CSIC, 28006-Madrid, Spain, Laboratoire de Chimie Organique Structurale, Uniuersitl Paul Sabatier, 31077-Toulouse ...
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Page 1. J. Org. Chem. 1994,59, 639-643 639 Heterocyclic Betaines. 19.' Unconventional Extended r-Systems Containing Pyridinium and Benzimidazolate Subunits. Synthesis and Characterization Ermitas Alcalde,' Immaculada ...
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ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select... more
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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ABSTRACT New simple imidazolium-based bidentate ligand precursors were prepared by a three-step protocol and bis(oxazoline) ligands were prepared in two steps. A Suzuki-Miyaura reaction was utilized to ascertain the activity of a... more
ABSTRACT New simple imidazolium-based bidentate ligand precursors were prepared by a three-step protocol and bis(oxazoline) ligands were prepared in two steps. A Suzuki-Miyaura reaction was utilized to ascertain the activity of a palladium(11) catalyst system generated in situ from an oxazolinyl-imidazolium cation, a bis(oxazoline), and palladium(II) acetate. Among them, two sterically hindered N-arylimidazolium cations demonstrated their efficiency with both aryl bromides and chlorides in low catalyst-system loading.
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A multistep route for obtaining the polynucleating open-chain systems 3-5 is reported. These advanced intermediates required elaborate processes that proceeded for the pentanuclear protophanes 3 in seven steps, whereas the trinuclear... more
A multistep route for obtaining the polynucleating open-chain systems 3-5 is reported. These advanced intermediates required elaborate processes that proceeded for the pentanuclear protophanes 3 in seven steps, whereas the trinuclear compounds 4 and 5 were obtained in six steps
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ABSTRACT The aza analogs of sesquifulvalene may adopt various structures, and of these several 1-alkyl-4-azplyhdene-1,4-dihydropyridines 8A ↔ 8B have been prepared by deprotonation of their corresponding 1-alkyl-4-azolyl-pyridinium salts.... more
ABSTRACT The aza analogs of sesquifulvalene may adopt various structures, and of these several 1-alkyl-4-azplyhdene-1,4-dihydropyridines 8A ↔ 8B have been prepared by deprotonation of their corresponding 1-alkyl-4-azolyl-pyridinium salts. These novel structures 8 could show a spectrum of properties ranging from those of erthylenes to betaines. Semiempirical (MNDO//MNDO), experimental dipole moment values (ca. 9.05 D), 1H and 18C NMR data, and single-crystal X-ray diffraction analysis of compound 16 are consistent with the betame character of these compounds. The electronic and molecular structure of azolium azotate inner salts 10 has been investigated. Theoretical calculations (MNDO//MNDO), experimental dipole moments (9.18 to 11.33 D), 1H and 13C NMR spectra, EIMS, and single-crystal X-ray diffraction analysis of compound 85 are consistent with the highly dipolar structure of this type of mesomeric betaines.
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... R. Calixarenes in Action; Imperial College Press: London, 2000. (7) (a) Lejeune, M.; Sémeril, D.; Jeunesse, C.; Matt, D.; Peruch, F.; Lutz, PJ; Ricard, L. Chem. Eur. ... Nicolas Marion and Steven P. Nolan. Accounts of Chemical... more
... R. Calixarenes in Action; Imperial College Press: London, 2000. (7) (a) Lejeune, M.; Sémeril, D.; Jeunesse, C.; Matt, D.; Peruch, F.; Lutz, PJ; Ricard, L. Chem. Eur. ... Nicolas Marion and Steven P. Nolan. Accounts of Chemical Research 2008 41 (11), pp 1440–1449. ...
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ABSTRACT By optimization of the geometry of 2, 5-dioxabicyclo[2. 2.1]heptane-3.6-dione (1) with an ab initio (RHF/6-31 G') calculation, we have found that a single synchro(+, +)-twist form (A) corresponds to the (1... more
ABSTRACT By optimization of the geometry of 2, 5-dioxabicyclo[2. 2.1]heptane-3.6-dione (1) with an ab initio (RHF/6-31 G') calculation, we have found that a single synchro(+, +)-twist form (A) corresponds to the (1 R,4R)-enantiomer (the dihedral angles of the lactone bridges are?0 = 2.6°). According to MM2(91) and MM3(92) calculations, (1R,4R)-1 exists as the s-ynchro(+, +)-A-twist (?0 = 3.9°) and the synchro(-, -)-B-twist (? = -3.8°) forms, respectively. Investigating the torsional energy surface of the dilactone 1 (MM2(91)), we found only the (1R,4R,P)-diastereomeric form (A), which is stabilized compared with the (1R,4P,M) form (B) (probably as a result of the more preferred dipole-dipole interaction of the carbonyl groups). According to the calculated puckering coordinates, the five-membered and six-membered moieties of the bicycle 1 are flattened compared with norbornane.
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Efficient access to the bis(imidazolyl)calixarene 2 and dicationic bis(imidazolium) salts 1a,b x 2X directly bonded to the upper rim of calixarene structure has been reported. Anion binding properties of the new receptors were studied by... more
Efficient access to the bis(imidazolyl)calixarene 2 and dicationic bis(imidazolium) salts 1a,b x 2X directly bonded to the upper rim of calixarene structure has been reported. Anion binding properties of the new receptors were studied by 1H NMR spectroscopic methods. Bis(N-butylimidazolium) dication 1a exhibited the best recognition properties toward carboxylate anions with a 1:1 receptor-anion binding stoichiometry, whereas the presence of a bulky group such as isopropyl (1b) increased the difficulty of both imidazolium moieties to be able to support the association with the same single anion.
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Changing the N,N-(dimethylamino)ethyl side chain in the N-[3-(aminoethyl)inden-5-yl]sulfonamide 5-HT(6) serotonin receptor agonists 1 by a conformationally rigid guanylhydrazone moiety at the indene 3-position led to the identification of... more
Changing the N,N-(dimethylamino)ethyl side chain in the N-[3-(aminoethyl)inden-5-yl]sulfonamide 5-HT(6) serotonin receptor agonists 1 by a conformationally rigid guanylhydrazone moiety at the indene 3-position led to the identification of the title indanylguanylhydrazones 6, which exhibited excellent binding affinities and an antagonistic response at the 5-HT(6) receptor, with K(i) and IC(50) values in the nanomolar range (K(i) >or= 1.2 nM, IC(50) >or= 47 nM, and I(max) <or= 173%).
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... Immaculada Dinarès*, Cristina Garcia de Miguel, Anna Ibáñez, Neus Mesquida and Ermitas Alcalde. Laboratori de ... b) E. Alcalde, C. Alvarez-Rúa, S. García-Granda, E. García-Rodriguez, N. Mesquida ... 4, 223 RSC Article ; (b) AR Toral,... more
... Immaculada Dinarès*, Cristina Garcia de Miguel, Anna Ibáñez, Neus Mesquida and Ermitas Alcalde. Laboratori de ... b) E. Alcalde, C. Alvarez-Rúa, S. García-Granda, E. García-Rodriguez, N. Mesquida ... 4, 223 RSC Article ; (b) AR Toral, AP de los Rios, FJ Hernández, MHA Janssen ...