Search results for ":QUÍMICA [UNESCO]"
showing 10 items of 49 documents
Evaluation and synthesis of 7-arylhydroxymethyltriazolopyridines as potential cardiovascular agents
2002
7-Arylhydroxymethyltriazolopyridines 3a-c and 4a-d were synthesized by regioselective lithiation of [1,2,3]triazolo[1,5-a]pyridines 1 and 2 and subsequent trapping of the 7-lithioderivatives formed using aryl aldehydes as electrophiles. The structural relationship between compounds 3a-c and 4a-d and arylethanolamines suggested their consideration as potential cardiovascular agents. A preliminary evaluation as vascular smooth muscle relaxants was carried out. These compounds did not act as α1-adrenoceptor antagonists and were unable to block calcium entry through voltage-dependent calcium channels. Abarca Gonzalez, Belen, Belen.Abarca@uv.es ; Ballesteros Campos, Rafael, Rafael.Ballesteros@uv…
Synthesis of novel polypyridylcarbonylpyridines from triazolopyridines. Building blocks in supramolecular chemistry
2009
The synthesis from triazolopyridines 1, of novel triazolopyridylcarbonylpyridylcarbonyltriazolopyridines (TPyCOPyCOTPy) (tpcpctp) 7, and polypyridylcarbonylpyridines (pPyCOPy) (ppcp) 14, building blocks in supramolecular chemistry, is described. These compounds are interesting polynitrogenated ligands as potential molecular sensors, new magnetic materials, single molecular magnets, or in the emerging science of nanomaterials. Abarca Gonzalez, Belen, Belen.Abarca@uv.es ; Ballesteros Campos, Rafael, Rafael.Ballesteros@uv.es ; Chadlaoui, Mimoun, michad@alumni.uv.es
Colorimetric sensing of anions by a neutral biphenyl based amide receptor
2007
A new colorimetric sensor for fluoride is described. Compound 1 shows an open structure and its behaviour is compared with that of two related closed compounds 2 and 3. In all cases, the red colour developed in the presence of fluoride can be related to deprotonation processes, however ligand 1 gives rise to a faster colour change than 2 or 3 because of its higher flexibility. Other halides as well as carboxylates have been studied and the stoichiometry and complexation constants for the corresponding ligands have been determined. Costero Nieto, Ana Maria, Ana.Costero@uv.es ; Peransi Llopis, Sergio Manuel, Sergio.Peransi@uv.es
Alkane oxidation by a carboxylate-bridged dimanganese(III) complex
2001
[EN] A new manganese( III) oxamato dimer possesing an unprecedented Mn-2(mu -O2CR)(mu -OH2. . .O2CR) core has been synthesised, structurally and magnetically characterised, and used as a catalyst for the oxidation of alkanes to alcohols and ketones by (BuO2H)-O-t and O-2 in CH2Cl2 at rt.
Fluorescent Sensing of Maleate versus Fumarate by a Neutral Cyclohexane Based Thiourea Receptor.
2006
A new cyclohexyl based fluorescent anion receptor, is able to recognize maleate versus fumarate both as their TMA salts. Costero Nieto, Ana Maria, Ana.Costero@uv.es ; Colera Llavata, Manuel, Manuel.Colera@uv.es ; Gaviña Costero, Pablo, Pablo.Gavina@uv.es ; Gil Grau, Salvador, Salvador.Gil@uv.es
Addition of dianions of carboxylic acids to imines. Influence of the acid in the outcome of the reaction
2009
The addition of different carboxylic acids dianions to N-benzylidenebenzeneamine have been studied. The outcome of the reaction depends on the acid. Saturated ones lead to β-aminoacids with good yields and syn-selectivity whereas α,β-unsaturated ones lead to α− and γ− regioisomers with a regioselectivity that depends on the steric hindrance around the reactive centre. From some of these unsaturated acids, polyunsaturated carboxylic acids can be obtained as a change in the reaction conditions lead to the in situ elimination of aniline. From o-methyl aromatic acids δ-aminoacids are isolated with uneven results. Those derived from six member arene carboxylic acids give, on standing, dihydro-2-…
From over-stoichiometric to sub-stoichiometric enantioselective protonation with 2-sulfinyl alcohols: A view in perspective
2005
A general study of the enantioselective protonation of prochiral enolates with 2-sulfinyl alcohols is reported. The modification of reaction conditions to reduce drastically the amount of chiral proton source needed to obtain a good enantiomeric excess is reported. The effects of the different factors controlling the stereoselectivity are clearly established. Different protocols for enolate generation are compared. Medio Simon, Mercedes, Mercedes.Medio@uv.es ; Aleman Lopez, Pedro Antonio, Pedro.Aleman@uv.es ; Gil Tomas, Jesus Javier, Jesus.J.Gil@uv.es ; Asensio, Aguilar Gregorio, Gregorio.Asensio@uv.es
Weighting non-covalent forces in the molecular recognition of C60. Relevance of concave–convex complementarity
2008
The relative contributions of several weak intermolecular forces to the overall stability of the complexes formed between structurally related receptors and [60]fullerene are compared, revealing a discernible contribution from concave–convex complementarity. Viruela Martin, Pedro Manuel, Pedro.M.Viruela@uv.es ; Viruela Martin, Rafael, Rafael.Viruela@uv.es ; Orti Guillen, Enrique, Enrique.Orti@uv.es
Pyridylcarbene formation by thermal decomposition of 7-bromo-3-methyl-[1,2,3]triazolo[1,5-a]pyridine under pressure
2007
7-Bromo-3-methyl-[1,2,3]triazolo[1,5-a]pyridine 1 at 1.7 atm and 100ºC decompose to form a pyridylcarbene intermediate by nitrogen expulsion. The carbene stabilization give 2-bromo-6- vinylpyridine 2, 1-(6-bromopyridin-2-yl)ethanol 3, 1-(6-Bromopyridin-2-yl)ethanone 4, 2- bromo-6-[2-(6-bromopyridin-2-yl)-2-methyl-trans-cyclopropyl]pyridine 5, and 2-bromo-6-[2-(6- bromopyridin-2-yl)-2-methyl-cis-cyclopropyl]pyridine 6. Abarca Gonzalez, Belen, Belen.Abarca@uv.es ; Ballesteros Campos, Rafael, Rafael.Ballesteros@uv.es
An efficient synthesis of new fluorinated uracil derivatives.
2003
A series of potentially biologically active fluorinated uracil derivatives has been prepared in three steps from oxazolines and fluorinated nitriles with good chemical yields. Fustero Lardies, Santos, Santos.Fustero@uv.es ; Sanz Cervera, Juan Francisco, Juan.F.Sanz@uv.es ; Asensio Martinez, Amparo, Amparo.Asensio@uv.es