Literatura académica sobre el tema "CHIMICA ORGANICA"
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Artículos de revistas sobre el tema "CHIMICA ORGANICA"
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Wirz, Jakob. "Mechanistic Organic Photochemistry". CHIMIA International Journal for Chemistry 61, n.º 10 (24 de octubre de 2007): 638–40. http://dx.doi.org/10.2533/chimia.2007.638.
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Herdlitschka, Andreas, Bartosz Lewandowski y Helma Wennemers. "Organic Molecular Weaves". CHIMIA International Journal for Chemistry 73, n.º 6 (26 de julio de 2019): 450–54. http://dx.doi.org/10.2533/chimia.2019.450.
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Heilbronner, Edgar y M. Volkan Kisakürek. "75 YEARS OFHELVETICA CHIMICA ACTA". Helvetica Chimica Acta 75, n.º 1 (5 de febrero de 1992): 1–20. http://dx.doi.org/10.1002/hlca.19920750102.
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Fürst, Andor, Georg Brubacher, Werner Meier y August Rüttimann. "DieHelvetica Chimica Actaund die Vitamine". Helvetica Chimica Acta 76, n.º 1 (10 de febrero de 1993): 1–59. http://dx.doi.org/10.1002/hlca.19930760102.
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HEIMGARTNER, H. y H. J. HANSEN. "ChemInform Abstract: Organic Photochemistry in the Mirror of Helvetica Chimica Acta". ChemInform 24, n.º 33 (20 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199333309.
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Huang, Hsin-Hua y Tomáš Šolomek. "Photochemistry Meets Porous Organic Cages". CHIMIA International Journal for Chemistry 75, n.º 4 (28 de abril de 2021): 285–90. http://dx.doi.org/10.2533/chimia.2021.285.
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Chemistry of porous organic cages has developed in the past decade as an alternative to the wellknown nanoporous materials based on extended networks, such as metal organic frameworks (MOFs) or covalent organic frameworks (COFs). Unlike these extended polymeric materials, the molecular nature of organic cages offers important advantages, such as solubility of the material in common organic solvents. However, a simultaneous combination of porosity and additional optoelectronic properties, common in MOFs and COFs, is still quite rare. Therefore, porous organic cages are relatively underdeveloped when compared to MOFs and COFs. Here, we highlight the rich possibilities the porous organic cages offer and discuss the recent development where interesting photophysical properties augment the porosity, including our own work.
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Borduas-Dedekind, Nadine, Sergey Nizkorodov y Kristopher McNeill. "UVB-irradiated Laboratory-generated Secondary Organic Aerosol Extracts Have Increased Cloud Condensation Nuclei Abilities: Comparison with Dissolved Organic Matter and Implications for the Photomineralization Mechanism". CHIMIA International Journal for Chemistry 74, n.º 3 (25 de marzo de 2020): 142–48. http://dx.doi.org/10.2533/chimia.2020.142.
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During their atmospheric lifetime, organic compounds within aerosols are exposed to sunlight and undergo photochemical processing. This atmospheric aging process changes the ability of organic aerosols to form cloud droplets and consequently impacts aerosol–cloud interactions. We recently reported changes in the cloud forming properties of aerosolized dissolved organic matter (DOM) due to a photomineralization mechanism, transforming high-molecular weight compounds in DOM into organic acids, CO and CO2. To strengthen the implications of this mechanism to atmospheric aerosols, we now extend our previous dataset and report identical cloud activation experiments with laboratory-generated secondary organic aerosol (SOA) extracts. The SOA was produced from the oxidation of α-pinene and naphthalene, a representative biogenic and anthropogenic source of SOA, respectively. Exposure of aqueous solutions of SOA to UVB irradiation increased the dried organic material's hygroscopicity and thus its ability to form cloud droplets, consistent with our previous observations for DOM. We propose that a photomineralization mechanism is also at play in these SOA extracts. These results help to bridge the gap between DOM and SOA photochemistry by submitting two differently-sourced organic matter materials to identical experimental conditions for optimal comparison.
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Mazet, Clément, Andreas Zumbuehl, Damien Jeannerat, Jiri Mareda, Alexandre Alexakis, E. Peter Kündig, Jérôme Lacour y Stefan Matile. "Organic Chemistry à la Genevoise". CHIMIA International Journal for Chemistry 63, n.º 12 (1 de diciembre de 2009): 816–21. http://dx.doi.org/10.2533/chimia.2009.816.
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Gryn'ova, Ganna y Clémence Corminboeuf. "Conceptual Framework of Organic Electronics". CHIMIA International Journal for Chemistry 73, n.º 4 (24 de abril de 2019): 245–51. http://dx.doi.org/10.2533/chimia.2019.245.
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Müller, Klaus. "Organic Fluorine: The Mighty Mite". CHIMIA International Journal for Chemistry 73, n.º 5 (29 de mayo de 2019): 417–19. http://dx.doi.org/10.2533/chimia.2019.417.
Texto completoTesis sobre el tema "CHIMICA ORGANICA"
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Loris, Alessandro <1972>. "Anidride carbonica e i suoi derivati in chimica organica". Doctoral thesis, Università Ca' Foscari Venezia, 2006. http://hdl.handle.net/10579/676.
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Dalla, Torre Davide <1995>. "Alchilazione dell’Isosorbitolo attraverso la chimica dei Dialchil carbonati". Master's Degree Thesis, Università Ca' Foscari Venezia, 2021. http://hdl.handle.net/10579/18827.
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Al giorno d’oggi il fabbisogno energetico mondiale dipende ancora dall’utilizzo dei combustibili fossili quali petrolio, gas naturale e carbone. L’eccessivo sfruttamento di questi ultimi ha causato ed è tutt’ora la causa di pesanti ripercussioni ambientali a livello mondiale come, ad esempio, l’aumento dell’emissione dei gas serra (CO2, NOx, VOCs) e la produzione di scarti plastici che stanno minacciando la flora e la fauna marina (isola di plastica nell’Oceano Pacifico). Inoltre, la disponibilità dei combustibili fossili è limitata e non può essere ripristinata nel breve tempo. È quindi importante optare per un’industria più sostenibile che possa far fronte alle problematiche socio-ambientali ed energetiche precedentemente riportate.
Una valida alternativa all’industria petrolchimica è la bioraffineria che utilizza risorse organiche naturali rinnovabili - le biomasse - come materie prime. In questo contesto, lo scopo del seguente studio di tesi è l’impiego di metodi alternativi per la funzionalizzazione di un derivato della biomassa, l’isosorbitolo e dei suoi epimeri (isomannitolo e isoiditolo). L’isosorbitolo - generalmente sintetizzato attraverso la ciclizzazione del D-sorbitolo, derivato idrogenato del D-glucosio - è un substrato interessante che possiede una struttura rigida e due funzionalità ossidriliche legate a carboni chirali che presentano una diversa reattività. Data la possibilità di ricavare il D-sorbitolo e l’isosorbitolo dalla biomassa e, in considerazione dell’interesse industriale di numerosi loro derivati (monomeri per polimeri, composti farmaceutici, solventi green), questi composti sono annoverati tra le dieci molecole piattaforma di origine rinnovabile (bio-based platform chemicals) dal Dipartimento di Energia degli Stati Uniti (DOE).
Nello specifico questo studio di tesi è incentrato sulla sintesi di alchil derivati dell’isosorbitolo che possono trovare impiego come solventi aprotici altobollenti, additivi per benzine e monomeri per polimeri (diallil isosorbitolo).
La prima parte della tesi è stata focalizzata sulla sintesi del dimetil isosorbitolo (DMI) a partire dall’isosorbitolo e dimetilcarbonato (DMC) – impiegato come reagente e solvente green - in presenza di un catalizzatore organico azotato. Le condizioni di reazione sono state ottimizzate e il miglior catalizzatore individuato - la N-metilpirrolidina (NMPy) – è stato studiato in dettaglio. La reazione di metilazione è stata testata in grande scala e diversi metodi di purificazione sono stati investigati per recuperare il dimetil isosorbitolo dalla miscela della reazione. Inoltre, per la prima volta tutti i sette intermedi di reazione che si formano nella conversione del sorbitolo in DMI sono stati isolati e caratterizzati; questo ha consentito lo studio dell’andamento della reazione di metilazione.
Nella seconda parte di questa tesi ci si è focalizzati sulla sintesi di alchil derivati dell’isosorbitolo attraverso la chimica dei dialchil carbonati in catalisi acida in quanto questi composti si ottengono in scarsa resa in condizioni di catalisi basica. In uno studio preliminare il dietil carbonato (DEC) è stato impiegato come agente alchilante e diversi catalizzatori acidi eterogenei ed omogenei sono stati testati. Catalizzatori inorganici omogeni come ad esempio puroliti, zeoliti e idrotaliciti hanno fornito risultati migliori. Ottimizzate le condizioni di reazione (temperatura, tempo, quantità di catalizatore), diversi dialchil carbonati sono stati testati per la preparazione di una famiglia di alchil derivati dell’isosobitolo.
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Meglioli, Nicolo' <1995>. "SINTESI DI BENZOSSAZEPINE E BENZOSSAZOCINE TRAMITE LA CHIMICA DEL DIMETIL CARBONATO". Master's Degree Thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/16126.
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Il laboratorio di ricerca presso il quale è stato condotto questo studio di tesi ha precedentemente riportato l’impiego dei dialchil carbonati (DACs) come agenti sacrificali - alternativi a derivati alogenati - per la sintesi di eterocicli a cinque e sei membri.
Lo scopo di questo progetto è quello di esplorare il chimismo del dimetil carbonato (DMC) per la sintesi di eterocicli a sette e otto membri, nello specifico, rispettivamente benzossazepine e benzossazocine.
I substrati che sono stati impiegati in questo progetto sono derivati dell’aldeide salicilica, e ammino alcoli come 2-ammino-1-etanolo (per i cicli a sette), e 3-ammino-1-propanolo (per i cicli a otto).
Una tipica procedura sintetica per la sintesi delle benzossazepine prevede due steps successivi:
1. Un'amminazione riduttiva tra aldeide salicilica e l’amminoetanolo.
2. Ciclizzazione del precursore ottenuto nel primo step impiegando il DMC come solvente e reagente in presenza di una base.
Questa metodologia sintetica ha portato alla sintesi di una libreria di benzossazepine, impiegando derivati dell’aldeide salicilica. Un’analoga procedura sintetica è stata applicata per la sintesi di diverse benzossazocine. Le rese dei prodotti ciclici dipende dal substrato impiegato e variano dal 40 all’80%.
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Sandron, Tommaso. "Investigation of Biological Membranes by NMR and ESI-MS Methodologies". Doctoral thesis, Università degli studi di Trento, 2010. https://hdl.handle.net/11572/368275.
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In the last decade there has been a new reappraisal of the function of lipids in the cell life, not only for their structural role as cell wall or for their energy storage function, but also for their significant function on signalling and protein recognition processes. This new attention on lipids has led to a new research field in the metabolomics world called “Lipidomics”. Lipidomics is more than just the complete characterization of all lipids in a particular biological sample. It is the comprehensive understanding of the influence of all lipids on a biological system with respect to cell signalling, membrane architecture, transcriptional and translational modulation, cell-cell and cell-protein interaction and response to environmental changes over time. The critical role of lipids in cell, tissue and organ physiology is already demonstrated by many human diseases involving the disruption of lipid metabolic enzymes and pathways. Examples of such diseases include diabetes, cancer, neurodegenerative disorders and infectious diseases. This represents a clue for understanding the molecular diversity observed in membrane phospholipids. Subtle biophysical properties are also another possible explanation of strong interest toward lipids especially with reference to the emerging field of heterogeneous membrane microdomains (rafts). The major goal in lipidomics is the identification of metabolic pathways which are activated or deactivated during development of an organism or when a cell is shifted from an established physiological condition to another physiological or pathological condition (metabolic learning). A better understanding of the regulation of underlying metabolic pathways is necessary to design novel strategies for intervention. In this thesis attention has been focused on two biological systems to demonstrate how the study of membrane lipids can help for a better understanding of the mechanisms involved in different biochemical processes. The first system tackled by our methodology is represented by lipid components in detergent resistant membranes (DRM) associated with the expression of Prostate-specific membrane antigen (PSMA); the latter is a 750-residue type II transmembrane glycoprotein of the normal prostate cells and one of the most promising biomarkers of prostate carcinoma as its expression is drastically increased in cancer cells protein involved in the prostate carcinoma. In particular, the complex glycosylated form of the protein is found in Lubrol insoluble DRMs. Many essential cellular events, such as protein sorting, endocytosis and signal transduction pathways, are triggered via association of the proteins directly implicated in these processes with DRMs. In the present work we report on the lipid composition of PSMA-associated microdomains. A qualitative screening was made by thin layer chromatography (TLC) followed by an extended NMR analysis of the sample. In particular, by taking 1H-, 13C- ed 31P-NMR spectra we were able to detect and quantify cholesterol and the relative contribution of all the lipids belonging to a given PL class (such as PC, PE and SM) with respect to the overall PL composition. On the other hand, Electrospray Ionization (ESI-MS) measurements and in-source collisional induced dissociations (CID) carried out on the same sample allowed us not only to establish the distribution of lipids among the PL classes but also to recognize some structural features such as the length and the number unsaturations of their acyl chains. The second problem tackled by following similar analytical methodologies was to analyze the detailed membrane lipids profile of insect larvae of the species Pseudodiamesa branickii and Diamesa cinerella to obtain information about the biochemical mechanisms involved in their thermal adaptative capabilities. Through NMR and LC-ESI-MS experiments we have obtained information about the composition of the lipid pool of these larvae that is formed essentially by triglycerides and phospholipids, with a variable inter-species PC/PE ratio. Coupling LC-MS profiling methods with in-source fragmentation data further has enhanced the ability to probe the lipidome, by supplementing lipid identification with structural information. We have observed an high level of unsaturation of the fatty acid chain as expected for low temperature-adapted species since unsaturated chain promote a more disordered and flexible membrane structure.. For Diamesa cinerella, from ESI data we could also infer some possible mechanism adopted to increase unsaturation of the fatty acid chain by the action of desaturases enzymes or by the insertion of PUFA chains.
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CAMPANER, PIETRO. "NUOVI APPROCCI AD INIBITORI PEPTIDOMIMETICI DELLA HIV-PROTEASI". Doctoral thesis, Università degli studi di Trieste, 2007. http://thesis2.sba.units.it/store/handle/item/12303.
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2005/2006La proteasi aspartica del virus HIV-1, agente responsabile dell'AIDS, è sicuramente uno tra gli enzimi attualmente più studiati e conosciuti in termini di struttura e attività. Permettendo la maturazione di nuove particelle infette e quindi il progredire dell'infezione essa svolge un ruolo cruciale nel ciclo replicativo del virus, la sua inibizione rappresenta, quindi, un importante obiettivo farmacologico, che coinvolge diverse discipline. Nel campo della chimica organica, la ricerca di efficaci inibitori peptidomimetici ha dato impulso allo sviluppo di nuove metodologie per la sintesi stereoselettiva di composti contenenti più centri chirali in forma enantiomericamente pura, da usarsi come isosteri dipeptidici per la sintesi di inibitori reversibili. L'HIV-proteasi dimostra caratteristiche del tutto peculiari; non solo è in grado, a differenza delle altre proteasi aspartiche eucariote, di idrolizzare legami ammidici aventi la prolina come residuo N-terminale, ma risulta attiva in una forma dimerica a simmetria C2 in cui l'attività idrolitica è presieduta da due residui di acido aspartico. Cercando il più possibile di sfruttare le informazioni derivanti dall'analisi della struttura dell'enzima bersaglio, in questa tesi di dottorato sono stati sviluppati alcuni protocolli per la sintesi stereoselettiva di nuovi inibitori peptidomimetici: -) un nuovo tipo di isosteri a struttura diamminodiolica contenenti un anello pirrolidinico, ottenuto mediante ciclizzazione altamente regio- e stereoselettiva di un'epossiammina, mediante deprotezione selettiva di un gruppo amminico primario in posizione ro. La sintesi dell'epossiammina viene ricondotta ad un P-chetofosfonato NBoc protetto, derivante da un amminoacido, ed un aminale ciclico N-Cbz protetto, derivante da un lattame. I diamminodioli ottenuti contengono quattro centri chirali adiacenti, il primo dei quali deriva dall' amminoacido di partenza, mentre la configurazione assoluta degli altri tre è controllata dall'induzione asimmetrica. Seguendo questo nuovo protocollo sono stati sintetizzati isosteri Val-Pro, Phe-Pro, Pro- Pro a configurazione (S,S,S,S), isosteri Phe-Pro (S,R,R,S) e (S,R,R,R) ed isosteri PhePro (S,S,S,S) in cui l'anello pirrolidinico, corrispondente al residuo della prolina, presenta dimensioni e sostituenti diversi. -) un nuovo tipo di isosteri monoidrossietilenici, in cui l'anello pirrolidinico è presente come tale o mimato da un triazolo, la cui sintesi sfrutta l'addizione coniugata di azide, controllata da uno stereocentro remoto, ad un opportuno composto carbonilico a,p-insaturo derivante da un amminoacido. -) una nuova tipologia di inibitori peptidomimetici, potenzialmente agenti con un meccanismo di inibizione irreversibile, basati su strutture epossialcoliche ottenute a partire da a-amminoacido. -) una nuova tipologia di inibitori che comuga l'azione di inibitori diversi supportati su un linker eterobifunzionale opportunamente sintetizzato ed in grado di aumentarne la biodisponibilità. Gli isosteri realizzati sono stati utilizzati per la sintesi di un piccolo set di inibitori peptidomimetici, le cui catene laterali contengono acidi fenossiacetici o sequenze peptidiche sintetizzate secondo i protocolli standard della sintesi peptidica. L'attività biologica degli inibitori realizzati, valutata seguendo l'idrolisi di substrati fluorogenici, è a livello micro- e nanomolare.
XIX Ciclo
1977
Versione digitalizzata della tesi di dottorato cartacea.
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Barbato, Francesca. "Caratterizzazione chimica della frazione organica di biochar e suoli trattati con biochar". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19423/.
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Il biochar, un materiale carbonioso prodotto dalla combustione di biomasse vegetali in assenza di ossigeno, utilizzato come ammendante nei suoli è in grado di apportare importanti benefici quali il sequestro di carbonio in forma stabile, il miglioramento della fertilità, l’adsorbimento superficiale di contaminanti. Tuttavia, sono presenti delle zone di incertezza che necessitano di essere indagate tra cui il suo impatto sulla dinamica della sostanza organica nel suolo.
Questo aspetto è stato considerato nel presente lavoro di tesi attraverso la caratterizzazione quantitativa e qualitativa del materiale organico solubile in acqua (o disciolto, DOM) derivante dal biochar. Il DOM rappresenta la frazione più attiva e mobile del materiale organico nei suoli. Il presente studio ha indagato la quantità e le caratteristiche del DOM derivante da diversi tipi di
biochar e rilasciato da suoli trattati con biochar. Sui biochar è stato studiato l’effetto dei parametri di produzione, temperatura di pirolisi, atmosfera e tipo di biomassa. Per i suoli sono stati considerati quelli di tre aziende agricole situate nel parmense coinvolte in un progetto PSR. L’obiettivo era studiare l’effetto che concentrazioni crescenti di biochar determinano sul rilascio e le caratteristiche di DOM. Il DOM è stato estratto con acqua dai campioni di biochar e suolo e le soluzioni sono state analizzate con tecniche di spettroscopia di fluorescenza in matrice di emissione eccitazione e di assorbimento molecolare UV-visibile. I dati sono stati normalizzati con il contenuto di carbonio determinato per combustione. I risultati mostrano che i parametri di pirolisi e il tipo di biomassa influenzano la composizione del DOM. Il biochar applicato a concentrazioni crescenti nei
suoli in genere non modifica significativamente la quantità di DOM. In alcuni casi si è osservata una diminuzione di DOM indicando che il biochar agisce più come materiale assorbente che come fonte di carbonio organico disciolto.
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Stenta, Marco <1979>. "Computational models in organic and bio-organic chemistry". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/1069/1/Tesi_Stenta_Marco.pdf.
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Stenta, Marco <1979>. "Computational models in organic and bio-organic chemistry". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/1069/.
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LUPIDI, GABRIELE. "Functionalization of Cyclic Structures for Advanced Biological and Pharmaceutical Applications". Doctoral thesis, Università degli Studi di Camerino, 2019. http://hdl.handle.net/11581/428901.
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The key components of the scaffold in pharmaceutical chemistry are ring systems, of different sizes, and are the fundamental factors of most of the drugs on the market today. Nowadays, the importance of cyclic structures is well understood by medicinal chemists, since they play a significant role in molecular properties such as the electronic distribution, three dimensionality, and molecule rigidity. They are often key factors in whole molecule properties such as lipophilicity or polarity and can determine molecular reactivity, metabolic stability, and toxicity. Cyclic structures have always fascinated organic and medicinal chemists, and many organic molecules form cycles with appealing biological properties. Research in cyclic chemistry continued to advance in synthetic methods development, conformational studies and investigation of their role for controlling biological functions.
This work, carried out in the Prof. Marcantoni’s research group at the University of Camerino (Camerino, Italy) with the collaboration of Dompé S.p.A. (L’Aquila, Italy) from December 2015 to December 2018 and in the Prof. Poli’s research group from January 2018 to July 2018 at the University Pierre and Marie Curie (Paris, France), had the objective to investigate new synthetic methodologies for the functionalization of cyclic compounds, as well as the formation of cyclic structures from acyclic precursor, for advanced biological purposes.
The first chapter focuses on the functionalization of the primary face of a β-cyclodextrin, in order to obtain a synthetic human receptor model, used for studying the possible interactions of this compound with a new class of biologically active compounds in development at Dompé S.p.A.
The second chapter, carried out in the Poli’s research group, describes the selective C-3 functionalization trials of 2-furaldehyde and its derivatives by Directed ortho Metalation (DoM) chemistry in presence of organolithium compounds and focuses on the study of degradation products. The reaction of an alkyllithium compound with an aromatic structure bearing a Direct Metalation Group (DMG) normally leads to an ortho-metalated intermediate. Good DMGs are strong complexing or chelating groups that have the effect of increasing the kinetic acidity of protons in the ortho position.
The third chapter focuses on the in-depth study of the mechanistic aspect on the formation of 5acylaminothiazoles starting from α-chloroglycinates, obtained by a new synthetic methodology developed in the Marcantoni’s research group.
Finally, the fourth chapter focuses on the study of the role of Cerium trichloride in the formation of cyclic compounds via Nazarov cyclization.
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STEFANINI, NICOLA. "Optimization of Industrial Polymeric Products to Improve Quality and Reduce Environmental Impact". Doctoral thesis, Università degli Studi di Camerino, 2019. http://hdl.handle.net/11581/428907.
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The present thesis is the result of three years’ collaboration between the University of Camerino and ELANTAS Europe Srl. The strong collaboration between university and companies allows to students like others and me to do research with an industrial approach, facing with the problematics of working life.
The work was carried out among the laboratory of Organic Chemistry of Prof. Enrico Marcantoni at the University of Camerino (Camerino, Italy), the R&D laboratory of ELANTAS Europe in Ascoli Piceno (Italy) and the R&D laboratory of ELANTAS PDG INC in Saint Louis (Missouri, USA).
The thesis concern the environmental impact of some industrial polymeric materials. Polymeric materials are very important in modern society: they have considerable advantages over products of other origins with lower costs with the same performance. Nevertheless, they allow some applications that some years ago would have been unthinkable (microencapsulation, shape memory materials, and many others).
At the same time, environmental impact is a crucial topic strictly linked to polymeric materials (as all others materials), and to the period we are living. The production of such materials is constantly growing, exceeding the production of many others materials, and it is becoming increasingly important to find ways to produce them more efficiently and to recover waste products. The consequences of a production without limitation and control could be catastrophic for the whole world and humankind too.
During my PhD, I worked on three industrial products in order to reduce their environmental impact, keeping their physical properties unchanged.
After a first general introduction on polymeric materials, their uses, and their production, the second chapter concern about improving a recovery process for waste PMMA. The study allowed identifying undesirable by-products formed during the thermal depolymerization of PMMA and removing them in the consequent re-polymerization by an innovative dissolution/re-precipitation method.
The third and fourth chapters deal with two coatings for wires electrical insulation, one based on polyurethanes (PU) and the other on polyesterimides (PEI). With the PU-based one, the target was to reduce the amount of loss material during the application stage and to increase the speed of application in order to reduce the energy consumption of the process. Whereas with the PEI-based enamel the purpose was to synthesized a solvent-free product using a twin-screw extruder and using recycled PET as alternative raw material to form the polyester part. The extruder technology is less energy consuming compare to the batches ones and allows working without solvents, since it can work with high viscosity materials. Moreover, the extruded product, with an additional system, can be potentially applied onto the wire with a higher thickness compare to the respective solventbased product, allowing a greater flow of current along the wire, thus improving the performance of the finished products (i.e. reducing the charging time of electrical motors).
Libros sobre el tema "CHIMICA ORGANICA"
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H, Brown William. Introduzione alla chimica organica. 3a ed. Napoli: SES, 2005.
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Some modern methods of organic synthesis. 3a ed. Cambridge [Cambridgeshire]: Cambridge University Press, 1986.
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Invitation to organic chemistry. Sudbury, Mass: Jones and Bartlett Publishers, 1999.
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Matteini, Mauro. La chimica nel restauro: I materiali dell'arte pittorica. Firenze: Nardini, 1989.
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1944-, Rawn J. David, ed. Organic chemistry. Upper Saddle River, N.J: Prentice Hall, 1996.
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Morrison, Robert Thornton. Organic Chemistry. 6a ed. New Delhi: Prentice Hall of India, 2001.
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Houben, Joseph. Methoden der organischen Chemie. 4a ed. Stuttgart: Thieme, 1986.
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Houben, Joseph. Methoden der organischen Chemie. Stuttgart: Georg Thieme Verlag, 1987.
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Houben, Joseph. Methoden der organischen Chemie. 4a ed. Stuttgart: Georg Thieme, 1985.
Buscar texto completoCapítulos de libros sobre el tema "CHIMICA ORGANICA"
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Taber, Douglass F. "C–C Bond Construction: The Galano Synthesis of 8-F3t-Isoprostane". En Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0025.
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Nobuaki Kambe of Osaka University devised (Synthesis 2014, 46, 1583) simple conditions for coupling an alkyl halide 1 with a Grignard reagent 2, leading to 3. Michael J. Chetcuti and Vincent Ritleng of the Université de Strasbourg arylated (Chem. Commun. 2014, 50, 4624) the ketone 4 with 5 to give 6. Ilhyong Ryu of Osaka Prefecture University effected (J. Org. Chem. 2014, 79, 3999) net conjugate acylation of the enone 8 to give 9 by reducing 7 in the presence of carbon monoxide. Yasushi Obora of Kansai University employed (Chem. Commun. 2014, 50, 2491) a borrowed hydrogen strategy to effect the net methylation of 10 to 11. There have been many examples of the alkylation of ketones using variations on this strategy. Robert H. Grubbs and Brian M. Stoltz of Caltech decarboxylated (Adv. Synth. Catal. 2014, 356, 130) an acid 12 to the corresponding alpha olefin 13. Lindsey O. Davis of Berry College combined (Tetrahedron Lett. 2014, 55, 3100) the imine 14 with the aldehyde 15 in the presence of 16 to give the enone 17. Masahiro Miyazawa of the University of Toyoma maintained (Synlett 2014, 25, 531) the geometric purity of 18 while coupling it with Me₃Al to give the diene 19. Naoki Kanoh of Tohoku University used (Eur. J. Org. Chem. 2014, 1376) the Micalizio protocol to add 22 with 21 to 20 to give the triene 23. Xile Hu of the Ecole Polytechnique Fédérale de Lausanne coupled (Org. Lett. 2014, 16, 2566) 25 with the iodide 24 to give the alkyne 26. Keiji Tanino of Hokkaido University prepared (Tetrahedron Lett. 2014, 55, 1097) the α-quaternary alkyne 29 by 1,2-addition of 28 to the ketone 27 followed by pinacol rearrangement. Zhaoguo Zhang of Shanghai Jiao Tong University and Tahar Ayad and Virginie Ratovelomanana-Vidal of Chimie ParisTech coupled (ACS Catal. 2014, 4, 44) 31 with the dienyl bromide 30 to deliver the disubstituted allene 32 in high ee. Amir H. Hoveyda of Boston College developed (Angew. Chem. Int. Ed. 2013, 52, 7694) a procedure for the preparation of alkynes such as 33 in substantial ee.
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Taber, Douglass F. "Substituted Benzenes: The Reddy Synthesis of Isofregenedadiol". En Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0062.
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Jianbo Wang of Peking University (Org. Lett. 2011, 13, 4988) and Patrick Y. Toullec and Véronique Michelet of Chimie ParisTech (Org. Lett. 2011, 13, 6086) developed conditions for the electrophilic acetoxylation of a benzene derivative 1. Seung Hwan Cho and Sukbok Chang of KAIST (J. Am. Chem. Soc. 2011, 133, 16382) and Brenton DeBoef of the University of Rhode Island (J. Am. Chem. Soc. 2011, 133, 19960) devised protocols for the electrophilic imidation of a benzene derivative 3. Vladimir V. Grushin of ICIQ Tarragona devised (J. Am. Chem. Soc. 2011, 133, 10999) a simple protocol for the cyanation of a bromobenzene 6 to the nitrile 7. Hua-Jian Xu of the Hefei University of Technology (J. Org. Chem. 2011, 76, 8036) and Myung-Jong Jin of Inha University (Org. Lett. 2011, 13, 5540) established conditions for the efficient Heck coupling of a chlorobenzene 8. Jacqueline E. Milne of Amgen/Thousand Oaks reduced (J. Org. Chem. 2011, 76, 9519) the adduct from the addition of 11 to 12 to deliver the phenylacetic acid 13. Jeffrey W. Bode of ETH Zurich effected (Angew. Chem. Int. Ed. 2011, 50, 10913) Friedel-Crafts alkylation of 14 with the hydroxamate 15 to give the meta product 16. B.V. Subba Reddy of the Indian Institute of Chemical Technology, Hyderabad took advantage (Tetrahedron Lett. 2011, 52, 5926) of the directing ability of the amide to effect selective ortho acetoxylation of 17. Similarly, Frederic Fabis of the Université de Caen Basse-Normandie used (J. Org. Chem. 2011, 76, 6414) the methoxime of 19 to direct ortho bromination, leading to 20. Teck-Peng Loh of Nanyang Technological University showed (Chem. Commun. 2011, 47, 10458) that the carbamate of 21 directed ortho C–H functionalization to give the ester 23. Yoichiro Kuninobu and Kazuhiko Takai of Okayama University rearranged (Chem. Commun. 2011, 47, 10791) the allyl ester 24 directly to the ortho-allylated acid 25. Youhong Hu of the Shanghai Institute of Materia Medica (J. Org. Chem. 2011, 76, 8495) and Graham J. Bodwell of Memorial University (J. Org. Chem. 2011, 76, 9015) condensed a chromene 26 with a nucleophile 27 to give the arene 28. C.V. Ramana of the National Chemical Laboratory prepared (Tetrahedron Lett. 2011, 52, 4627) the arene 31 by condensing 29 with 30 with high regioselectivity.
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Taber, Douglass F. "Carbon-Carbon Bond Formation". En Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0025.
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Akiya Ogawa of Osaka Prefecture University found (Tetrahedron Lett. 2010, 51, 6580) that the Sm-mediated reductive coupling of a halide 1 with CO2 to give the carboxylic acid 2 was strongly promoted by visible light. Gregory C. Fu of MIT designed (Angew. Chem. Int. Ed. 2010, 49, 6676) a Ni catalyst for the coupling of a primary borane 4 with a secondary alkyl halide 3. James P. Morken of Boston College devised (Org. Lett. 2010, 12, 3760) conditions for the carbonylative conjugate addition of a dialkyl zinc to an enone 6 to give the 1,4-dicarbonyl product 7. Louis Fensterbank of the Institut Parisien de Chimie Moléculaire developed (Angew. Chem. Int. Ed. 2010, 49, 8721; not illustrated) a protocol for the conjugate addition of alkyl boranes to enones. Hyunik Shin of LG Life Science, Daejeon, and Sang-gi Lee of Ewha Womans University showed (Tetrahedron Lett. 2010, 51, 6893) that the intermediate from Blaise homologation of a nitrile 8 was a powerful nucleophile, smoothly opening an epoxide 10 to deliver 11. Sébastien Reymond and Janine Cossy of ESPCI ParisTech found (J. Org. Chem. 2010, 75, 5151) that FeCl3 smoothly catalyzed the coupling of an alkenyl Grignard 13 with the primary iodide 12. The Ti-mediated coupling of an alkyne 16 with an allylic alkoxide 15 (J. Am. Chem. Soc. 2010, 132, 9576) developed by Glenn C. Micalizio of Scripps/Florida was the key step in the total synthesis (J. Am. Chem. Soc. 2010, 132, 11422) of lehualide B. Huanfeng Jiang of the South China University of Technology observed (Chem. Commun. 2010, 46, 8049) that KI added to a bromoalkyne 18 to give the dihalide 19 with high geometric control. Haruhiko Fuwa of Tohoku University improved (Org. Lett. 2010, 12, 5354) the selective hydroiodination of a methyl alkyne 20 to 21. Takuya Kurahashi and Seijiro Matsubara of Kyoto University devised (Chem. Commun. 2010, 46, 8055) the Ni-catalyzed three-component coupling of an alkyne 22, methyl acrylate 23, and phenyl isocyanate to give the doubly homologated lactam 24. Patrick H. Toy of the University of Hong Kong showed (Synlett 2010, 1997; Org. Lett. 2010, 12, 4996 for a polymer with covalently attached base) that resin-bound triphenylphosphine participated efficiently in the Wittig coupling of 26 with an aldehyde 25.
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Usai, Alessandro y Nicolas Garnier. "L’insediamento nuragico di Sa Osa (Cabras - OR). Nuovi dati su materiali organici e analisi chimiche". En Manger, boire, se parfumer pour l'éternité, 293–301. Publications du Centre Jean Bérard, 2021. http://dx.doi.org/10.4000/books.pcjb.8285.
Texto completoActas de conferencias sobre el tema "CHIMICA ORGANICA"
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Ivanova, Anastasia. "Consumul chimic de oxigen în apele râului Prut". En Simpozion "Modificări funcționale ale ecosistemelor acvatice în contextul impactului antropic și al schimbărilor climatice". Institute of Zoology, Republic of Moldova, 2021. http://dx.doi.org/10.53937/9789975151979.05.
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Chemical oxygen demand (COD) was determined in water samples from the Prut River during 2020. Mean values of CODMn and CODCr ranged from 3.5 to 9.0 mg O2/L (5.5 ± 1.2 mg O2/L) and from 12 to 45 mg O2/L (22 ± 8.7 mg O2/L) respectively. The analysis of the results demonstrates the existence in the waters of the Prut River of easily degradable organic substances (an indicator of fresh and permanent pollution) and those that are difficult to degrade. According to the requirements of the Regulation on the quality of surface waters, the water from the Prut River for the period studied in accordance to the chemical oxygen demand with manganese is assigned to quality class I-II (very good – good), and after chemical oxygen demand with chrome – to class II-III (good – moderately polluted).
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Colaux-Castillo, Catherine G. y Alain Krief. "EnCOrE (Encyclopédie de Chimie Organique Electronique): an original way to represent and transfer Knowledge from freshmen to researchers in Organic Chemistry". En 3rd International LeGE-WG Workshop: GRID Infrastructure to Support Future Technology Enhanced Learning. BCS Learning & Development, 2003. http://dx.doi.org/10.14236/ewic/3lege2003.5.
Texto completoInformes sobre el tema "CHIMICA ORGANICA"
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Rafaeli, Ada, Russell Jurenka y Chris Sander. Molecular characterisation of PBAN-receptors: a basis for the development and screening of antagonists against Pheromone biosynthesis in moth pest species. United States Department of Agriculture, enero de 2008. http://dx.doi.org/10.32747/2008.7695862.bard.
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The original objectives of the approved proposal included: (a) The determination of species- and tissue-specificity of the PBAN-R; (b) the elucidation of the role of juvenile hormone in gene regulation of the PBAN-R; (c) the identificationof the ligand binding domains in the PBAN-R and (d) the development of efficient screening assays in order to screen potential antagonists that will block the PBAN-R. Background to the topic: Moths constitute one of the major groups of pest insects in agriculture and their reproductive behavior is dependent on chemical communication. Sex-pheromone blends are utilised by a variety of moth species to attract conspecific mates. In most of the moth species sex-pheromone biosynthesis is under circadian control by the neurohormone, PBAN (pheromone-biosynthesis-activating neuropeptide). In order to devise ideal strategies for mating disruption/prevention, we proposed to study the interactions between PBAN and its membrane-bound receptor in order to devise potential antagonists. Major conclusions: Within the framework of the planned objectives we have confirmed the similarities between the two Helicoverpa species: armigera and zea. Receptor sequences of the two Helicoverpa spp. are 98% identical with most changes taking place in the C-terminal. Our findings indicate that PBAN or PBAN-like receptors are also present in the neural tissues and may represent a neurotransmitter-like function for PBAN-like peptides. Surprisingly the gene encoding the PBAN-receptor was also present in the male homologous tissue, but it is absent at the protein level. The presence of the receptor (at the gene- and protein-levels), and the subsequent pheromonotropic activity are age-dependent and up-regulated by Juvenile Hormone in pharate females but down-regulated by Juvenile Hormone in adult females. Lower levels of pheromonotropic activity were observed when challenged with pyrokinin-like peptides than with HezPBAN as ligand. A model of the 3D structure of the receptor was created using the X-ray structure of rhodopsin as a template after sequence alignment of the HezPBAN-R with several other GPCRs and computer simulated docking with the model predicted putative binding sites. Using in silico mutagenesis the predicted docking model was validated with experimental data obtained from expressed chimera receptors in Sf9 cells created by exchanging between the three extracellular loops of the HezPBAN-R and the Drosophila Pyrokinin-R (CG9918). The chimera receptors also indicated that the 3ʳᵈ extracellular loop is important for recognition of PBAN or Diapause hormone ligands. Implications: The project has successfully completed all the objectives and we are now in a position to be able to design and screen potential antagonists for pheromone production. The successful docking simulation-experiments encourage the use of in silico experiments for initial (high-throughput) screening of potential antagonists. However, the differential responses between the expressed receptor (Sf9 cells) and the endogenous receptor (pheromone glands) emphasize the importance of assaying lead compounds using several alternative bioassays (at the cellular, tissue and organism levels). The surprising discovery of the presence of the gene encoding the PBAN-R in the male homologous tissue, but its absence at the protein level, launches opportunities for studying molecular regulation pathways and the evolution of these GPCRs. Overall this research will advance research towards the goal of finding antagonists for this important class of receptors that might encompass a variety of essential insect functions.