Relevant bibliographies by topics / Composés carbonylés

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Composés carbonylés'

Author: Grafiati
Published: 4 June 2021
Last updated: 25 May 2024

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Journal articles on the topic "Composés carbonylés"

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Aussems, C., S. Jaspers, G. Leroy, and F. van Remoortere. "Étude théorique des systèmes hétéroatomiques conjugués. III. les composés carbonylés." Bulletin des Sociétés Chimiques Belges 78, no. 9-10 (September 2, 2010): 487–93. http://dx.doi.org/10.1002/bscb.19690780907.

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Troupel, Michel, Maiténa Oçafrain, Eric Dolhem, Jean-Claude Folest, and Rachid Barhdadi. "Electrosynthéses de composés carbonylés catalysées par des complexes du nickel: Activation du monoxyde de carbone ou de composés acylés." Canadian Journal of Chemical Engineering 76, no. 6 (December 1998): 1013–19. http://dx.doi.org/10.1002/cjce.5450760607.

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Hofer, Roger, Daniel Evard, and André Jacot-Guillarmod. "Reactivité de composés carbonylés avec des cétènes en présence d'alkoxydes de titane ou de zirconium. 3e communication." Helvetica Chimica Acta 68, no. 4 (June 26, 1985): 969–74. http://dx.doi.org/10.1002/hlca.19850680422.

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Fournier, Françoise, and Michel Fournier. "Transferts d'électrons assistés par les métaux de transition:influence de la nature du cation métallique sur la réduction de composés carbonylés en milieu aprotique." Canadian Journal of Chemistry 64, no. 5 (May 1, 1986): 881–90. http://dx.doi.org/10.1139/v86-146.

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The pinacolisation of ketones is enhanced when a bivalent transition metal cation is present. This phenomenon is general and occurs with Cr2+, Mn2+, Fe2+, Co2+, Zn2+ but not with Ni2+. The cathodic reduction leads to α-glycols with a good yield, without any resin production, and at a less negative potential than that of the ketone itself. The distribution of all isolated compounds is dependent on the Lewis character-acidity and complexing power of the metallic cation. Thus, for the dimerization, the greatest specificity is generally observed when Fe2+ is present. For the chalcone, the better stereoselectivity is obtained with Zn2+. No evidence of initial carbonyl complex of the metal ion was shown.
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Bernard, Didier, Alain Doutheau, and Jacques Gore. "Nouvelle voie d'acces aux composes carbonyles α- alleniques." Tetrahedron 43, no. 12 (January 1987): 2721–32. http://dx.doi.org/10.1016/s0040-4020(01)86877-0.

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6

Guiheneuf, Georges, José-Luis M. Abboud, and Widded Bouab. "Effets de solvant sur les complexes par transfert de charge iode – composés thiocarbonylés." Canadian Journal of Chemistry 65, no. 9 (September 1, 1987): 2106–8. http://dx.doi.org/10.1139/v87-349.

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The effects of solvents on different iodine – thiocarbonyl base charge-transfer complexes of variable stability have been examined and these are compared with the effects of solvents of the iodine – carbonyl compound complexes. There is an inversion of the effect of those solvents that can form hydrogen bonds on going from one series to the other, which is attributed to the fact that the carbonyl compounds are hard bases while the thiocarbonyl compounds are soft bases. [Journal translation]
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7

Schneider, M., M. J. Gil, A. Reliquet, J. C. Meslin, J. Levillain, M. Vazeux, D. Jury, J. L. Mieloszynski, and D. Paquer. "Correlations Des DéPlacements Chimiques En Rmn 13C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles." Phosphorus, Sulfur, and Silicon and the Related Elements 134, no. 1 (February 1, 1998): 295–305. http://dx.doi.org/10.1080/10426509808545470.

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8

Thuy, Vu Moc. "Utilisation du Chromate Imprégné Sur Alumine Pour L'Oxydation des Dérivés Halogènes En Composés Carbonyles." Bulletin des Sociétés Chimiques Belges 102, no. 4 (September 1, 2010): 299–300. http://dx.doi.org/10.1002/bscb.19931020413.

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Thuy, Vu Moc, and Pierre Maitte. "Utilisation Du Permanganate Impregne Sur Alumine Pour L'Oxydation Des Alcools En Composes Carbonyles." Bulletin des Sociétés Chimiques Belges 98, no. 11 (September 1, 2010): 877–78. http://dx.doi.org/10.1002/bscb.19890981110.

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10

Marques, Marcelo Volpatto, Denis Russowsky, and L. M. A. Fontoura. "ANÁLISE CONFORMACIONAL DE COMPOSTOS DE BIGINELLI COM ATIVIDADE ANTINEOPLÁSICA." Eclética Química Journal 35, no. 4 (January 22, 2018): 33. http://dx.doi.org/10.26850/1678-4618eqj.v35.4.2010.p33-38.

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Dihydropyrimidinones, such as monastrol and analogues, are heterocycles with known antineoplastic activity. Conformational analysis represents an important preliminary step in structure-activity correlation studies. Herein we describe the conformational analysis of monastrol and analogues by AM1 semiempirical and ab initio HF/6-31G* calculations. Four equilibrium geometries were found (s-cis/ap, s-cis/sp, strans/ap and s-trans/sp), and the important internal rotations were those of the ab-unsaturated carbonyl system and of the aryl group connected to the heterocycle
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Dissertations / Theses on the topic "Composés carbonylés"

1

Roy, Olivier. "Synthèse énantiosélective et palladoinduite de composés carbonylés." Reims, 2001. http://www.theses.fr/2001REIMS027.

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La méthodologie du laboratoire utilisant la réaction en cascade de déprotection-décarboxylation-tautomérisation énantiosélective d'espèces énoliques à partir de β-cétoesters de benzyle racémiques a permis de préparer des cétones cycliques. L'extension aux méthylchroman-4-ones nous a conduit à développer une nouvelle voie de synthèse de ces substrats utilisant des produits simples, et faisant intervenir deux étapes clés, une substitution d'acétates allyliques par des phénols et une cyclisation électrophile aromatique. Lors de l'étude de la réaction de déprotection-décarboxylation-tautomérisation d'esters de benzyle dérivés de 3-méthylchroman-4-ones, il a été mis en évidence l'influence de la nature du palladium et des substituants du groupement aromatique. Cette récation a également été appliquée sur des β-cétoesters de benzyle linéaires. Leur comportement s'est avéré différent de celui des cétones cycliques. La présence d'un groupement aromatique sur le carbone prochiral est primordiale alors que la nature du substituant sur le groupement carbonyle a peu d'influence sur l'énantiosélectivité. Cette méthodologie a permis la synthèse d'acides 2-arylpropioniques optiquement actifs. Des modèles permettant d'expliquer les interactions responsables de l'énantiosélectivités sont discutés.
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Cadran, Nicolas. "Fluoration nucléophile d'alcools et de composés carbonylés." Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/public/theses_doctorat/2006/CADRAN_Nicolas_2006.pdf.

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L’objectif de cette thèse était la mise au point de méthodes permettant de convertir des composés hydroxylés ou carbonylés en dérivés mono ou gem-difluorés qui ne fassent appel qu’à des anions fluorures (fluoration nucléophile). La transformation d’aldéhydes en composés gem-difluorés via la formation de gem-fluorosulfonates par action du système fluorure de tosyle/imidazole a été examinée en premier. Le résultat espéré n’a pas été atteint : l’alcool 4-nitrobenzylique est converti en son dérivé fluoré avec un rendement faible à l’aide de ce réactif. Par contre, une oxydation originale d’aldéhydes aromatiques en esters ou amides correspondants a été observée. A la suite, l’objectif fixé a été atteint en faisant usage des sels de 1-méthyl-2-fluoro-pyridinium (sels de Mukaiyama) et ces résultats ont conduit à un dépôt de brevet (Rhodia/CNRS). En présence d’un hydrogénodifluorure d’ammonium (TBABF), ces sels permettent de transformer des alcools et des aldéhydes aromatiques en, respectivement, fluorures et gem-difluorures d’alkyle. Les cétones ne réagissent pas dans ces conditions. Par contre, les α-dicétones donnent les α,α’-difluorocétones correspondantes. Enfin, des α-hydroxyesters homochiraux sont convertis en fluoroesters avec une stéréospécificité appréciable (ee≈90%). La fluoration des alcools et des aldéhydes à l’aide des difluoroalkylamines (réactifs de Yarovenko) a aussi été étudiée. En opérant en présence de TBABF et de triéthylamine, la fluoration d’alcools par ces réactifs est significativement améliorée, alors que celle des aldéhydes l’est par ajout de KHF2. Enfin, une méthode de fluoration d’alcools et d’aldéhydes aromatiques utilisant le fluorure de cyanuryle et le TBABF a été développée. Nous montrons que les amides, mieux les diarylsulfoxydes, catalysent ces fluorations
The main purpose of this work was to design new methodologies aimed at converting both hydroxy and keto compounds into mono and difluoro compounds, respectively, by making use exclusively of fluoride anions (nucleophilic fluorination). Attempted use of the tosyl fluoride. DBU reagent proved unrewarding; only trace amount of alkyl fluorides were formed from alcohols. Interestingly, reacting non-enolizable aldehydesin these conditions resulted in an unprecedented oxidation process and in operating in a light alcohol, various benzaldehydes have been efficiently converted into the corresponding benzoates. More rewarding with regards to the initial goal was the use of N-methyl-2-fluoropyridinium tosylate (i. E. Mukaiyama reagent). By using an ammonium hydrogenodifluoride as a co-reagent these salts permitted not only to fluorinate various alcohols but also p-substituted benzaldehydes and α-diketones, the target fluoro or difluoro compounds being in each case isolated in acceptable yields. An interesting application was the conversion of homochiral α-hydroxyesters into the corresponding α-fluoroesters with good e. E. ; providing the conversion was kept low. Next, the fluorination of alcohols and aldehydes with difluoroalkylamines has been studied. In each case, through examination of the conditions permitted to improve the yields in fluoro compounds i. A. By operating either in presence of an ammonium difluoride (alcohols) or of KHF2 (aldehydes). Finally, the preceding fluorinations have been shown to occur by using cyanuryl fluoride, a catalysis by diarylsulfoxides being then observed
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Delair, Philippe. "Réductions et alkylations énantiosélectives de composés carbonylés." Grenoble 1, 1993. http://www.theses.fr/1993GRE10107.

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Le but de ce travail a ete d'etudier la chimio et la stereoselectivite de certaines reactions. Le passage direct et selectif d'un ester en aldehyde reste delicat a realiser surtout a grande echelle, de plus les resultats decrits dans la litterature relatif a l'emploi d'hydrures d'aluminium et de lithium modifies sont contradictoires. Nous avons montre que de tels hydrures triamines realisent cette transformation avec une excellente selectivite mais que les quantites de produits attendus sont limitees par une reaction secondaire difficile a eviter. La reduction des cetones au moyen d'oxazaborolidines conduit aux alcools aromatiques avec une excellente enantioselectivite mais elle est plus faible pour les cetones aliphatiques. La modification des substituants de l'inducteur a ete effectuee dans le but de determiner l'influence des differents facteurs sur l'induction et a mis en evidence la complexite de ce phenomene. L'enantioselectivite des alkylations d'aldehydes par le diethylzinc est egalement moins satisfaisante en serie aliphatique qu'en serie aromatique. L'elaboration de valinols diversement substitues nous a permis de proposer un auxiliaire chiral parmi les plus performants decrits dans la litterature, dans les deux series
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Zair, Touriya. "Synthèse stéréosélective et cyclisation catalysée par le palladium (0) des 1,5-hexadiène-3-ols/ Touriya Zair." Aix-Marseille 3, 1991. http://www.theses.fr/1991AIX30048.

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La stereochimie de l'addition des organo-magnesiens allyliques sr les enones a ete etudiee. Sur les enones acycliques, l'addition du chlorure de crotylmagnesium conduit a des 1,5-hexadiene-3-ols obtenus sous forme d'un melange erythro-threo. La proportion d'isomere threo croit avec celle de la configuration 5-cis de l'enone. Avec les dialkylidenecyclohexanones, l'addition axiale du chlorure deconfiguration erythro. Un modele compact a ete propose pour decrire l'etat de transition. Les 1,5-hexadiene-3-ols traites au reflyx de l'acide acetique par des quantites catalytiques de tetrakis triphenylphosphine palladium en presen,ce d'acide trifluoroacetique se cyclisent en 1-methyl-1,3-cyclopentadienes. Un mecanisme est propose sur la base des resultats obtenus avec des molecules marquees au deuterium
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Pándy-Szekeres, István Dávid. "Nouvelles synthèses par voie organosilicique." Bordeaux 1, 1985. http://www.theses.fr/1985BOR10596.

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Le present travail decrit: la synthese de disilyl-1, 1-propenes-2 et disilyl-1,3-propenes a partir de composes carbonyles , b-insatures via les dithiolanes allyliques correspondants, et l'etude de quelques proprietes ; la recherche d'une methode efficace d'agrandissement de cycle applicable a la norbornenone en vue de la synthese de la bicyclo (3, 2, 1) octene-6-one-2, intermediaire cle dans la construction du squelette de la nauclexine, un alcaloide naturel ; cette synthese de la bicyclo (3, 2, 1) octene-6-one-2
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Berkani, Mohamed. "Réduction de composés carbonylés par transfert d'hydrogène sur catalyseurs solides." Poitiers, 1995. http://www.theses.fr/1995POIT2282.

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L'objectif de ce travail etait d'utiliser des alcools comme donneurs d'hydrogene pour reduire le groupe carbonyle d'aldehydes ou de cetones, en phase vapeur et en dynamique. Le transfert d'hydrogene d'un alcool a un compose carbonyle, bien connu en chimie organique (reaction de meerwein-ponndorf-verley) est catalyse par les bases. Nous avons donc selectionne pour cette etude plusieurs catalyseurs solides basiques: oxyde de magnesium, alumine, alumine impregnee par de la potasse, zeolithes plus au moins basiques. L'alcool choisi est le cyclopentanol. Une etude thermodynamique prealable a montre que le transfert d'hydrogene entre le cyclopentanol et une cetone modele (la cyclohexanone) etait tout a fait possible, mais dependait de variables operatoires telles que la temperature de reaction et les pressions partielles des reactifs. Les experiences preliminaires realisees sur les differents catalyseurs ont confirme les resultats de cette etude. Parallelement au transfert d'hydrogene qui se produit sur les sites basiques, on observe une autre reaction: la deshydratation des alcools (le cyclopentanol et le cyclohexanol forme) se produisant sur les sites acides des catalyseurs. Ceci nous a permis d'etablir une echelle de basicite/acidite des catalyseurs utilises. Les resultats des tests catalytiques sont en parfait accord avec les mesures d'acidite et de basicite des catalyseurs realisees independamment soit par voie catalytique soit par voie physico-chimique. La transformation du melange alcool-cetone peut donc etre utilisee comme reaction modele pour caracteriser les catalyseurs acido-basiques. Nous avons enfin essaye d'utiliser le transfert d'hydrogene pour reduire selectivement le groupe c=o de differents derives carbonyles insatures. Les resultats obtenus montrent que cette reaction est possible, mais il semble que la structure du compose carbonyle (possibilite de cyclisation, conjugaison de la double liaison,) joue un role tres important dans son mode de transformation
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Luart, Denis. "Etude de l'action du chlorure d'oxalyle sur des tétracarbonyl ferrates fonctionnalisés : accès à de nouveaux complexes bimétalliques et carbéniques." Brest, 1997. http://www.theses.fr/1997BRES2007.

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Les complexes porteurs de deux ligands organiques carbonyles sont souvent envisages comme intermediaires dans les reactions catalytiques de carbonylation. Le premier chapitre de ce travail presente une etude de la reaction d'addition du chlorure d'oxalyle sur des alcoxycarbonyl tetracarbonyl ferrates, reaction conduisant a des complexes mono ou bimetalliques bis-alcoxycarbonyles du fer. Le second chapitre montre que ces composes modeles n'induisent pas thermiquement la formation d'oxalates par couplage carbone-carbone entre les deux ligands alcoxycarbonyle. Le troisieme chapitre est consacre a l'extension de la reaction d'addition du chlorure d'oxalyle sur des ferrates porteurs de differents types de ligands organiques carbonyles. Les reactions realisees a partir des carbamoyl ferrates permettent l'obtention de complexes isocyanures ou de carbenes metallacycliques.
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Franc, Céline. "Fonctionnalisations sélectives de composés aromatiques et hétéroaromatiques." Palaiseau, Ecole polytechnique, 2004. http://www.theses.fr/2004EPXX0059.

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LEFEBVRE, OLIVIER. "Reactivite des difluoroenoxysilanes. Applications a la synthese de composes mono et gem-difluores." Reims, 1999. http://www.theses.fr/1999REIMS006.

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Les difluoroenoxysilanes prepares a partir d'acylsilanes et de trifluoromethyltrimethylsilane, via une sequence addition-rearrangement de brook-elimination, sont utilises comme synthons pour la synthese de composes gem-difluores et monofluores. Nous avons mis au point des procedures one pot avec divers substrats electrophiles actives par les acides de lewis : - leur alkylation avec des esters allyles et benzyles, catalysee par le triflate de trimethylsilyle, a permis la synthese d'analogues difluores de terpenes naturels (difluorogeraniol, difluorolinalol, difluorodehydro-ar-curcumene, difluoro-ar-turmerone). - l'aldolisation optimisee en utilisant une quantite catalytique de triflate d'ytterbium conduit aux , -difluoro--hydroxycetones. La reduction de ces aldols difluores par voies radicalaire ou biochimique a ete etudiee. - la reaction avec des enones egalement activees par le triflate d'ytterbium conduit aux 2,2-difluoro-1,5-dicetones. La cyclisation de ces dicetones avec une quantite catalytique de koh a permis la synthese des difluorocyclohexenones. Avec un exces de koh l'aromatisation des difluorocyclohexenones est observee. Selon les possibilites d'enolisation de l'acylsilane precurseur de la difluorodicetone les ortho- ou les para-fluorophenols sont regiospecifiquement formes. - enfin, avec les donneurs de glycosyle, les difluoroenoxysilanes forment des difluoro-c-glycosides ou des difluoro-c-disaccharides.
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Brestaz, Marc. "Synthèse et caractérisation de polyesters à partir du diméthylcétène et de composés carbonylés." Phd thesis, INSA de Rouen, 2009. http://tel.archives-ouvertes.fr/tel-00560884.

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L'objectif de cette étude est de synthétiser et de caractériser des polyesters entre le diméthylcétène et des composés carbonylés choisis (acétone, méthyléthylcétone et acéthaldéhyde) par deux voies distinctes : une copolymérisation directe, et une voie passant d'abord par la synthèse de la beta-lactone puis sa polymérisation par ouverture de cycle. La caractérisation a mis en évidence la structure parfaitement alternée du polyester entre le diméthylcétène et l'acétone, et des structures plus complexes avec la méthyléthylcétone et l'acétaldéhyde. Les analyses ont également montré le caractère polymorphe complexe de ces copolymères. Les trois beta-lactones correspondantes ont également été synthétisées. Seule la polymérisation de la beta-lactone avec l'acétaldéhyde a été menée à bien, du fait de son faible encombrement stérique. Enfin, une étude cinétique par infrarouge a également été effectuée et a permis de mieux connaître les cinétiques de polymérisation par ouverture de cycle.
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Books on the topic "Composés carbonylés"

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International Workshop on the Enzymology and Molecular Biology of the Carbonyl Metabolism. Enzymology and molecular biology of carbonyl metabolism 3. New York: Plennum Press, 1991.

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Henry, Weiner, Crabb David W, Flynn T. Geoffrey, and International Workshop on Enzymology and Molecular Biology of Carbonyl Metabolism (6th : 1992 : Dublin, Ireland), eds. Enzymology and molecular biology of carbonyl metabolism 4. New York: Plenum Press, 1993.

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(Editor), David W. Crabb, Henry Weiner (Editor), and Bendicht Wermuth (Editor), eds. Enzymology and Molecular Biology of Carbonyl Metabolism 3 (Advances in Experimental Medicine and Biology). Springer, 1991.

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Enzymology and Molecular Biology of Carbonyl Metabolism 4. Springer, 2011.

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Crabb, David W., Henry Weiner, and T. Geoffrey Flynn. Enzymology and Molecular Biology of Carbonyl Metabolism 4. Springer London, Limited, 2012.

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Organometallic Chemistry, 1983 (Organometallic Chemistry). Science and Behavior Books, 1985.

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Book chapters on the topic "Composés carbonylés"

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Patel, Ashok Raj, Geetika Patel, Arti Srivastava, Bhaskar Sharma, Goutam Kumar Patra, and Subhash Banerjee. "Nano-Catalysis in the Selective Oxidation of Alcohols and Anilines." In Diverse Strategies for Catalytic Reactions, 33–58. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815079036123020004.

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Recently, the development of eco-friendly and sustainable organic redox reactions has attracted considerable attention. In the classification of catalysis, the two categories, homogeneous and heterogeneous catalysis, have their own advantages and limitations. Thus, we need catalytic species that show properties like homogeneous and heterogeneous catalysts. Nano-catalysts fulfill the above requirements as it works as a “linker” between the homogeneous and heterogeneous catalysts. In past years, various heterogeneous nanomaterials have been used in different organic transformations as green catalysts due to their larger surface area and smaller size. Most importantly, nano-catalysts are the modern catalysts that promise green synthesis. Methods: Selective oxidation of alcohols to carbonyl compounds is essential due to the wide applications of carbonyl compounds in pharmaceutical, agrochemical, fragrances, food industries, and electronic industries. Traditional methods for the synthesis of carbonyl compounds require a large number of oxidants; homogeneous catalysts, heavy metal catalysts, and precious metal supports are used. Further, aromatic azo compounds, composed of two phenyl groups interconnected by nitrogen-nitrogen double bonds, are well-known chromophores that have important applications in the synthesis of dyes, pigments, indicators, chemosensors, radical initiators, food additives, and therapeutic, diagnostic, and pro-drug agents as well as building blocks of various polymers and natural products. These compounds exhibited photophysical properties and significant applications in electronics and optics. Several methods have been developed for the preparation of aromatic azo compounds. Moreover, the selective oxidation of aniline is an important and useful organic reaction for the synthesis of oxygenated compound such as azoxybenzenes. Azoxybenzenes have attracted special importance as synthetically useful intermediates, precursors and employed as dyes, reducing agents, chemical stabilizers, and polymerization inhibitors, liquid crystals displays and therapeutic medicines. Here, some green approaches have discussed for the preparation of azoxy compounds. Conclusion: This review focused on the recent green methods for the selective oxidation of alcohols to carbonyl compounds and direct oxidative azo-coupling of anilines to aromatic azo and azoxy compounds using heterogeneous nano-based catalysts.
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Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. "Assignment of the Absolute Configuration of Monofunctional Compounds by Double Derivatization." In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.003.0006.

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The assignment of secondary alcohols can be carried out by using one of several CDAs [13–15]. The most used and most reliable ones are MPA, 9-AMA, and MTPA [35–40]. Figure 3.1 shows their structures, the correlation models, and a summary of the experimental conditions. MPA and 9-AMA esters share the same conformational composition [37, 39] and only differ in the intensity of their shieldings; therefore both auxiliaries present the same correlation between sign distribution and stereochemistry. MTPA has a different conformational composition and correlation model [38]. As shown in Chapter 1, MPA esters of secondary alcohols and other AMAA esters (e.g., 9-AMA esters) are composed of two sp/ap conformers in fast equilibrium [37, 39]. The sp conformer is more stable than the ap conformer, and this allows the NMR spectrum of an AMAA ester to be interpreted as if it had originated from just the sp form: carbonyl, Cα, and methoxy groups in the auxiliary part and a methine group (Cα′-H) at the alcohol moiety are in the same plane. When we consider this conformation in the (R)- and the (S)-AMAA esters, the L1 group is located under the shielding cone of the aryl in the (R)-AMAA ester, while the L2 is shielded in the (S)-AMAA ester (we strongly recommended that the reader builds Dreiding, or similar, models to assist in visualizing this spatial array). A subtraction defined as the chemical shift in the (R)-AMAA ester minus that in the (S)-AMAA ester results in a negative value for L1 and a positive one for L2 (i.e., negative ΔδRS for L1 and positive ΔδRS for L2). Therefore, for any secondary alcohol derivatized as an AMAA ester, the protons showing a positive ΔδRS sign are located in the tetrahedron around the asymmetric carbon (Cα′) as L2 (at the back) while the protons resulting in a negative ΔδRS take the position of L1.
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Bianchi, Thomas S. "Dissolved Gases in Water." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0012.

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Dissolved gases are critically important in many of the biogeochemical cycles of estuaries and coastal waters. However, only recently have there been large-scale collaborative efforts addressing the importance of coupling between estuaries and the atmosphere. For example, the Biogas Transfer in Estuaries (BIOGEST) project, which began in 1996, was focused on determining the distribution of biogases [CO2, CH4, CO, non-methane hydrocarbons, N2O, dimethyl sulfide (DMS), carbonyl sulfide (COS), volatile halogenated organic compounds, and some biogenic volatile metals] in European estuaries and their impact on global budgets (Frankignoulle and Middelburg, 2002). The role of the estuaries and other coastal ocean environments as global sources and/or sinks of key greenhouse gases, like CO2, have also been a subject of intense interest in recent years (Frankignoulle et al., 1996; Cai and Wang, 1998; Raymond et al., 1997, 2000; Cai, 2003; Wang and Cai, 2004). Similarly, O2 transfer across the air–water interface is critical for the survival of most aquatic organisms. Unfortunately, many estuaries around the world are currently undergoing eutrophication, which commonly results in low O2 concentrations (or hypoxic ≤ 2 mg L−1), due to excessive nutrient loading in these systems (Rabalais and Turner, 2001; Rabalais and Nixon, 2002). To understand how gases are transferred across the air–water boundary we will first examine the dominant atmospheric gases and physical parameters that control their transport and solubility in natural waters. The atmosphere is also composed of aerosols, which are defined as condensed phases of solid or liquid particles, suspended in state, that have stability to gravitational separation over a period of observation (Charlson, 2000). Chemical composition and speciation in atmospheric aerosols is important to understanding their behavior after deposition, and is strongly linked with the dominant sources of aerosols (e.g., windblown dust, seasalt, combustion). The importance of aerosol deposition to estuaries and coastal waters, via precipitation (rain and snow) and/or dry particle deposition, has received considerable attention in recent years. For example, dry and wet deposition of nutrients (Paerl et al., 2002; Pollman et al., 2002) and metal contaminants (Siefert et al., 1998; Guentzel et al., 2001) has proven to be significant in biogeochemical budgets in wetlands and estuaries.
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Conference papers on the topic "Composés carbonylés"

1

Cooper, Kelsey, LeAnn Faidley, Sarah Timmons, Yi Han, and Wei Hong. "Magnetic Properties of Ferrogels." In ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3829.

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This paper presents the magnetic properties of ferrogels subject to cyclic magnetic fields. Ferrogels are compliant materials composed of a nonmagnetic, flexible matrix with a micro- or nano-sized magnetic powder filler. In this paper a poly-vinyl-alcohol matrix is chemically cross-linked with sodium tetraborate and micro-sized particles of carbonyl iron are dispersed randomly in the sample. Ferrogels exhibit active behavior characterized by a deformation, a stiffness increase, and a change of other properties when subjected to a magnetic field making them promising future actuator materials. Furthermore, since the composition of ferrogels can be easily varied the active properties of these materials can be designed over a wide range of possibilities. In order for this to be possible however, a thorough understanding of the active behavior of these materials and its dependence on external factors is necessary. This paper focuses on the magnetic properties of PVA/carbonyl iron ferrogels and how they are dependent on internal and external factors. Magnetization of the ferrogel sample will be measured under a uniform, sinusoidal magnetic field for constrained and unconstrained samples with various iron concentrations and under a range of excitation frequencies. Uniform excitation fields of up to 500 G are created by passing current through a coil that is substantially larger than the sample size. Excitation frequencies of 0.1 Hz to 20 Hz and iron concentrations of 12 wt%, 20 wt% and 27 wt% are investigated. The magnetization is determined by measuring the voltage induced in a pickup coil that surrounds the ferrogel sample. The objective of these tests is to investigate the magnetic properties of a poly-vinylalcohol/carbonyl iron ferrogel to help in the future design of ferrogels for specific applications.
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2

Yashaa, Ammar S., and Souran Manoochehri. "Fabrication and Characterization of Micro-Patterned Magnetorheological Elastomeric Structures." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64535.

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This paper presents fabrication and characterization of micro-patterned magnetorheological elastomeric structures composed of magnetorheological fluid (MRF) sandwiched with magnetorheological elastomeric (MRE) materials. The MRE structures are made of polydimethylsiloxane (PMDS) with and without an additive of carbonyl iron (CI) particles with a size range of 6–9 um and the MRF is composed of silicon fluid mixed with the CI particles of the same size range. Three different SU-8 master molds of plain, longitudinal, and latitudinal patterns are constructed. Also, four MR elastomeric structures of different CI particle arrangements of isotropic MRE, anisotropic top-to-bottom-aligned MRE, anisotropic side-to-side-aligned MRE, and pure PDMS for each SU-8 master mold are fabricated. MRE structures are then characterized by using a tensile testing machine under a normal condition (off-state) and a low magnetic field condition (on-state). The tensile tests were performed to experimentally investigate their tunable properties. Later, the data gathered are compared for different conditions.
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3

Rincón, D. A., M. C. Daza, and M. Doerr. "Application of the quantum theory of atoms in molecules (QTAIM) to the study of the enzymatic kinetic resolution of propranolol, an amino alcohol with pharmaceutical applications." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020135.

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Propranolol, ((R,S)-1-iso-propylamino-3-(1-naphthoxy)-2-propanol), is a β-adrenergic antagonist and is commercially available as a racemic mixture. Only the S-enantiomer has the desired therapeutic effect. Therefore, many researchers have been working on strategies to obtain S-propranolol with high enantiomeric purity. One approach to carry out the acetylation of (R,S)-Propranolol using Candida antarctica lipase B, CalB. This reaction leads to an enantiomeric purity of 96% at a relatively low conversion rate of 30 %. In our research group, we have been studying this reaction. The CalB active site is composed by the triad catalytic (ASP 187, HIS 224 and SER 105) and oxyanion hole (GLN 106 and THR 40). In a previous work, a QM/MM (Quantum Mechanics / Molecular Mechanics) study was carried out, using a QM region consisting only of the catalytic triad of CalB and (R,S)-propranolol [1]. In the present study, we investigate the effect of expanding the quantum region to include the oxyanion hole and to comprehend the effect of intermolecular hydrogen bonds present between the (R,S)-propranolol and the CalB active site. The electronic structure was analyzed using the Quantum Theory of Atoms In Molecules, QTAIM. Our results show that: 1. the studied reactions are more exothermic with the inclusion of the oxyanion hole than with only the catalytic triad. 2. the intermolecular interactions between (R,S)-propranolol and the CalB active site are dominated by hydrogen bonds (HB). Among those HBs, only one between propranolol and HIS 224, and another one between THR 40 and the carbonyl oxygen of acetylated SER 105 play an important role.
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