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Artigos de revistas sobre o assunto "Cycloaddition du CO2"
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Krompiec, Stanisław, Aneta Kurpanik-Wójcik, Marek Matussek, Bogumiła Gołek, Angelika Mieszczanin e Aleksandra Fijołek. "Diels–Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry". Materials 15, n.º 1 (27 de dezembro de 2021): 172. http://dx.doi.org/10.3390/ma15010172.
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Phenyl, naphthyl, polyarylphenyl, coronene, and other aromatic and polyaromatic moieties primarily influence the final materials’ properties. One of the synthetic tools used to implement (hetero)aromatic moieties into final structures is Diels–Alder cycloaddition (DAC), typically combined with Scholl dehydrocondensation. Substituted 2-pyranones, 1,1-dioxothiophenes, and, especially, 1,3-cyclopentadienones are valuable substrates for [4 + 2] cycloaddition, leading to multisubstituted derivatives of benzene, naphthalene, and other aromatics. Cycloadditions of dienes can be carried out with extrusion of carbon dioxide, carbon oxide, or sulphur dioxide. When pyranones, dioxothiophenes, or cyclopentadienones and DA cycloaddition are aided with acetylenes including masked ones, conjugated or isolated diynes, or polyynes and arynes, aromatic systems are obtained. This review covers the development and the current state of knowledge regarding thermal DA cycloaddition of dienes mentioned above and dienophiles leading to (hetero)aromatics via CO, CO2, or SO2 extrusion. Particular attention was paid to the role that introduced aromatic moieties play in designing molecular structures with expected properties. Undoubtedly, the DAC variants described in this review, combined with other modern synthetic tools, constitute a convenient and efficient way of obtaining functionalized nanomaterials, continually showing the potential to impact materials sciences and new technologies in the nearest future.
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Lin, Yi-Feng, Yu-Rou Lai, Hsiang-Ling Sung, Tsair-Wang Chung e Kun-Yi Andrew Lin. "Design of Amine-Modified Zr–Mg Mixed Oxide Aerogel Nanoarchitectonics with Dual Lewis Acidic and Basic Sites for CO2/Propylene Oxide Cycloaddition Reactions". Nanomaterials 12, n.º 19 (1 de outubro de 2022): 3442. http://dx.doi.org/10.3390/nano12193442.
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The utilization of CO2 attracts much research attention because of global warming. The CO2/epoxide cycloaddition reaction is one technique of CO2 utilization. However, homogeneous catalysts with both Lewis acidic and basic and toxic solvents, such as DMF, are needed in the CO2/epoxide cycloaddition reaction. As a result, this study focuses on the development of heterogeneous catalysts with both Lewis acidic and basic sites for the CO2 utilization of the CO2/epoxide cycloaddition reactions without the addition of a DMF toxic solvent. For the first time, the Zr–Mg mixed oxide aerogels with Lewis acidic and basic sites are synthesized for the CO2/propylene oxide (PO) cycloaddition reactions. To further increase the basic sites, 3-Aminopropyl trimethoxysilane (APTMS) with -NH2 functional group is successfully grafted on the Zr–Mg mixed oxide aerogels. The results indicate that the highest yield of propylene carbonate (PC) is 93.1% using the as-developed APTMS-modified Zr–Mg mixed oxide aerogels. The as-prepared APTMS-modified Zr–Mg mixed oxide aerogels are great potential in industrial plants for CO2 reduction in the future.
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Gao, Jie, Chengguang Yue, Hao Wang, Jiaxin Li, He Yao, Mei-Yan Wang e Xinbin Ma. "CeO2-ZrO2 Solid Solution Catalyzed and Moderate Acidic–Basic Sites Dominated Cycloaddition of CO2 with Epoxides: Halogen-Free Synthesis of Cyclic Carbonates". Catalysts 12, n.º 6 (9 de junho de 2022): 632. http://dx.doi.org/10.3390/catal12060632.
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For the production of cyclic carbonates from the cycloaddition of CO2 with epoxides, halogen pollution and product purity are two of the most common problems due to the usage of homogeneous halogen-containing catalysts such as ammonium salt and alkali metal halide. Hence, the development of a novel, halogen-free and efficient catalyst for the synthesis of high-purity cyclic carbonates is significant. Here, a series of acid–base bifunctional Ce1-xZrxO2 nanorods were successfully prepared. The Ce1-xZrxO2 nanorods could catalyze the cycloaddition of CO2 with epoxides efficiently without any halogen addition. Especially for the Ce0.7Zr0.3O2 catalyst, a conversion of 96% with 100% 1,2-butylene carbonate selectivity was achieved. The excellent catalytic performance of Ce1-xZrxO2 nanorods is attributed to the formation of the CeO2-ZrO2 solid solution, which contributes to abundant moderate acidic–basic active sites on the catalyst surface. It is the synergistic effect of moderate acidic–basic sites that dominates the conversion of CO2 with epoxides, which will supply important references for the synthesis of efficient metal oxide catalyst for the cycloaddition of CO2 with epoxides.
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Noh, Jinmi, Dasom Kim, Jihyun Lee, Minyoung Yoon, Myung Park, Kang Lee, Youngjo Kim e Min Kim. "Three Component Controls in Pillared Metal-Organic Frameworks for Catalytic Carbon Dioxide Fixation". Catalysts 8, n.º 11 (20 de novembro de 2018): 565. http://dx.doi.org/10.3390/catal8110565.
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Three components of pillared metal-organic frameworks (MOFs, three components = metal ion, carboxylic acid ligand, and N-chelating ligand) were controlled for CO2 cycloaddition catalysts to synthesize organic cyclic carbonates. Among the divalent metals, Zn2+ showed the best catalytic activity, and in DABCO (1,4-diazabicyclo[2.2.2]octane)-based MOFs, hydroxy-functionalized DMOF-OH was the most efficient MOF for CO2 cycloaddition. For the BPY (4,4’-bipyridyl)-type MOFs, all five prepared BMOFs (BPY MOFs) showed similar and good conversions for CO2 cycloaddition. Finally, this pillared MOF could be recycled up to three times without activity and crystallinity loss.
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Shang, Shu, Wei Shao, Xiao Luo, Ming Zuo, Hui Wang, Xiaodong Zhang e Yi Xie. "Facet Engineering in Constructing Lewis Acid-Base Pairs for CO2 Cycloaddition to High Value-Added Carbonates". Research 2022 (15 de outubro de 2022): 1–9. http://dx.doi.org/10.34133/2022/9878054.
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Cycloaddition of epoxides with CO2 to synthesis cyclic carbonates is an atom-economic pathway for CO2 utilization with promising industry application value, while its efficiency was greatly inhibited for the lack of highly active catalytic sites. Herein, by taking BiOX (X=Cl, Br) with layered structure for example, we proposed a facet engineering strategy to construct Lewis acid-base pairs for CO2 cycloaddition, where the typical BiOBr with (010) facets expose surface Lewis acid Bi sites and Lewis base Br sites simultaneously. By the combination of in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and theoretical calculations, the oxygen atom of the epoxide is interacted with the Lewis acid Bi site to activate the ternary ring, then facilitates the attack of the carbon atom by the Lewis base Br site for the ring-opening of the epoxide, which is the rate-determining step in the cycloaddition reaction. As a result, the BiOBr-(010) with rich surface Lewis acid-base pairs showed a high conversion of 85% with 100% atomic economy in the synthesis of cyclic-carbonates without any cocatalyst. This study provides a model structure for CO2 cycloaddition to high value-added long chain chemicals.
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Kiatkittipong, Kunlanan, Muhammad Amirul Amin Mohamad Shukri, Worapon Kiatkittipong, Jun Wei Lim, Pau Loke Show, Man Kee Lam e Suttichai Assabumrungrat. "Green Pathway in Utilizing CO2 via Cycloaddition Reaction with Epoxide—A Mini Review". Processes 8, n.º 5 (8 de maio de 2020): 548. http://dx.doi.org/10.3390/pr8050548.
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Carbon dioxide (CO2) has been anticipated as an ideal carbon building block for organic synthesis due to the noble properties of CO2, which are abundant renewable carbon feedstock, non-toxic nature, and contributing to a more sustainable use of resources. Several green and proficient routes have been established for chemical CO2 fixation. Among the prominent routes, this review epitomizes the reactions involving cycloaddition of epoxides with CO2 in producing cyclic carbonate. Cyclic carbonate has been widely used as a polar aprotic solvent, as an electrolyte in Li-ion batteries, and as precursors for various forms of chemical synthesis such as polycarbonates and polyurethanes. This review provides an overview in terms of the reaction mechanistic pathway and recent advances in the development of several classes of catalysts, including homogeneous organocatalysts (e.g., organic salt, ionic liquid, deep eutectic solvents), organometallic (e.g., mono-, bi-, and tri-metal salen complexes and non-salen complexes) and heterogeneous supported catalysts, and metal organic framework (MOF). Selection of effective catalysts for various epoxide substrates is very important in determining the cycloaddition operating condition. Under their catalytic systems, all classes of these catalysts, with regard to recent developments, can exhibit CO2 cycloaddition of terminal epoxide substrates at ambient temperatures and low CO2 pressure. Although highly desired conversion can be achieved for internal epoxide substrates, higher temperature and pressure are normally required. This includes fatty acid-derived terminal epoxides for oleochemical carbonate production. The production of fully renewable resources by employment of bio-based epoxy with biorefinery concept and potential enhancement of cycloaddition reactions are pointed out as well.
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Lei, Yizhu, Yali Wan, Wei Zhong, Dingfu Liu e Zhou Yang. "Phosphonium-Based Porous Ionic Polymer with Hydroxyl Groups: A Bifunctional and Robust Catalyst for Cycloaddition of CO2 into Cyclic Carbonates". Polymers 12, n.º 3 (5 de março de 2020): 596. http://dx.doi.org/10.3390/polym12030596.
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The integration of synergic hydrogen bond donors and nucleophilic anions that facilitates the ring-opening of epoxide is an effective way to develop an active catalyst for the cycloaddition of CO2 with epoxides. In this work, a new heterogeneous catalyst for the cycloaddition of epoxides and CO2 into cyclic carbonates based on dual hydroxyls-functionalized polymeric phosphonium bromide (PQPBr-2OH) was presented. Physicochemical characterizations suggested that PQPBr-2OH possessed large surface area, hierarchical pore structure, functional hydroxyl groups, and high density of active sites. Consequently, it behaved as an efficient, recyclable, and metal-free catalyst for the additive and solvent free cycloaddition of epoxides with CO2. Comparing the activity of PQPBr-2OH with that of the reference catalysts based on mono and non-hydroxyl functionalized polymeric phosphonium bromides suggested that hydroxyl functionalities in PQPBr-2OH showed a critical promotion effect on its catalytic activity for CO2 conversion. Moreover, PQPBr-2OH proved to be quite robust and recyclable. It could be reused at least ten times with only a slight decrease of its initial activity.
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Shi, Jinghua, Jinliang Song, Jun Ma, Zhaofu Zhang, Honglei Fan e Buxing Han. "Effective synthesis of cyclic carbonates from CO2 and epoxides catalyzed by KI/cucurbit[6]uril". Pure and Applied Chemistry 85, n.º 8 (4 de abril de 2013): 1633–41. http://dx.doi.org/10.1351/pac-con-12-10-09.
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The development of efficient, inexpensive, and nontoxic catalysts for cycloaddition of CO2 with epoxides to produce five-membered cyclic carbonates is a very interesting topic. In this work, cycloaddition of CO2 with propylene oxide (PO) to produce propylene carbonate (PC) catalyzed by potassium halides (KCl, KBr, and KI) in the presence of cucurbit[6]uril (CB[6]) was studied at various conditions. It was discovered that the potassium halides and CB[6] had excellent synergetic effect in promoting the reaction, and the KI/CB[6] catalytic system was the most efficient among them. The decrease of the activity and selectivity of KI/CB[6] was negligible after the catalytic system was reused five times. Further study indicated that the KI/CB[6] catalytic system was also very active and selective for the cycloaddition of CO2 with other epoxides, such as glycidyl phenyl ether, epichlorohydrin, and styrene oxide. The mechanism for the synergetic effect of KI and CB[6] was also discussed.
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Tangyen, Niracha, Wuttichai Natongchai e Valerio D’Elia. "Catalytic Strategies for the Cycloaddition of CO2 to Epoxides in Aqueous Media to Enhance the Activity and Recyclability of Molecular Organocatalysts". Molecules 29, n.º 10 (14 de maio de 2024): 2307. http://dx.doi.org/10.3390/molecules29102307.
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The cycloaddition of CO2 to epoxides to afford versatile and useful cyclic carbonate compounds is a highly investigated method for the nonreductive upcycling of CO2. One of the main focuses of the current research in this area is the discovery of readily available, sustainable, and inexpensive catalysts, and of catalytic methodologies that allow their seamless solvent-free recycling. Water, often regarded as an undesirable pollutant in the cycloaddition process, is progressively emerging as a helpful reaction component. On the one hand, it serves as an inexpensive hydrogen bond donor (HBD) to enhance the performance of ionic compounds; on the other hand, aqueous media allow the development of diverse catalytic protocols that can boost catalytic performance or ease the recycling of molecular catalysts. An overview of the advances in the use of aqueous and biphasic aqueous systems for the cycloaddition of CO2 to epoxides is provided in this work along with recommendations for possible future developments.
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Bester, Karol, Agnieszka Bukowska, Aleksandra Kawka, Maciej Pytel e Wiktor Bukowski. "Salophen chromium(iii) complexes functionalized with pyridinium salts as catalysts for carbon dioxide cycloaddition to epoxides". RSC Advances 14, n.º 4 (2024): 2466–80. http://dx.doi.org/10.1039/d3ra07750k.
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Novel multifunctional one-component catalysts for the cycloaddition of CO2 to epoxides. The selective and effective conversion of substrates to cyclic carbonates possible using 0.01 mol% catalyst and a low CO2 pressure.
Teses / dissertações sobre o assunto "Cycloaddition du CO2"
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Yeamin, Md Bin. "Catalytic CO2 Cycloaddition with Epoxides into Cyclic Carbonates: Synergies from Computational to Experimental Studies". Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672267.
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La utilització d'el CO2 com a matèria primera química ha demostrat ser una estratègia important per reduir les emissions de CO2 a l'atmosfera i, per tant, per trobar un equilibri en el cicle natural de l'carboni. No obstant això, l'activació d'aquesta petita molècula estable és molt difícil. De fet, els substrats reactius amb alta energia interna poden facilitar les transformacions químiques de el CO2 per compensar la seva estabilitat termodinàmica. A més, es necessiten catalitzadors eficaços per superar l'elevada barrera cinètica de l'activació. Entre els molts mètodes catalítics, la catàlisi tèrmica segueix sent el mètode més utilitzat per ampliar els processos de fixació de CO2 a nivell industrial. Es necessiten catalitzadors amb més activitat i selectivitat en condicions de reacció més suaus. Per tant, el nostre objectiu és avaluar l'eficiència dels materials de baix cost i abundants en terra com a catalitzadors per a la cicloaddició de CO2 amb epòxids d'alt contingut energètic. També pretenem entendre el comportament d'aquests catalitzadors a partir d'estudis mecanístics computacionals, i millorar el seu disseny corroborant amb el seu rendiment catalític experimental per aquesta reacció de transformació de el CO2.
En aquesta Tesi estudiem 3 catalitzadors diferents per a la reacció de cicloaddició de CO2 amb epòxids sota gradient tèrmic. Els catalitzadors són biomasses lignocelulósiques com materials vegetals més abundants, 1,10-fenatronina derivada de quatre donants de nitrogen que contenen complexos de zinc, i un complex derivat de ciclam de l'element més abundant, el ferro. Els efectes cooperatius d'aquests catalitzadors binaris en combinació amb un cocatalizador, el bromur de tetrabutilo i amoni (TBAB), s'han dilucidat a partir d'estudis mecanístics computacionals. En els estudis experimentals, les reaccions catalítiques s'optimitzen per substrats estàndard, i els percentatges de conversió dels substrats es corroboren amb les barreres d'energia d'activació dels mecanismes de reacció, quan s'apliquen. També s'analitza la naturalesa dels diferents llocs actius catalítics des del punt de vista de l'abast de l'substrat.La utilización del CO2 como materia prima química ha demostrado ser una estrategia importante para reducir las emisiones de CO2 a la atmósfera y, por tanto, para encontrar un equilibrio en el ciclo natural del carbono. Sin embargo, la activación de esta pequeña molécula estable es muy difícil. De hecho, los sustratos reactivos con alta energía interna pueden facilitar las transformaciones químicas del CO2 para compensar su estabilidad termodinámica. Además, se necesitan catalizadores eficaces para superar la elevada barrera cinética de la activación. Entre los muchos métodos catalíticos, la catálisis térmica sigue siendo el método más utilizado para ampliar los procesos de fijación de CO2 a nivel industrial. Se necesitan catalizadores con mayor actividad y selectividad en condiciones de reacción más suaves. Por lo tanto, nuestro objetivo es evaluar la eficiencia de los materiales de bajo coste y abundantes en tierra como catalizadores para la cicloadición de CO2 con epóxidos de alto contenido energético. También pretendemos entender el comportamiento de estos catalizadores a partir de estudios mecanísticos computacionales, y mejorar su diseño corroborando con su rendimiento catalítico experimental para esta reacción de transformación del CO2. En esta Tesis estudiamos tres catalizadores diferentes para la reacción de cicloadición de CO2 con epóxidos bajo gradiente térmico. Los catalizadores son biomasas lignocelulósicas como materiales vegetales más abundantes, 1,10-fenatronina derivada de cuatro donantes de nitrógeno que contienen complejos de zinc, y un complejo derivado de ciclam del elemento más abundante, el hierro. Los efectos cooperativos de estos catalizadores binarios en combinación con un cocatalizador, el bromuro de tetrabutilo y amonio (TBAB), se han dilucidado a partir de estudios mecanísticos computacionales. En los estudios experimentales, las reacciones catalíticas se optimizan para sustratos estándar, y los porcentajes de conversión de los sustratos se corroboran con las barreras de energía de activación de los mecanismos de reacción, cuando se aplican. También se analiza la naturaleza de los diferentes sitios activos catalíticos desde el punto de vista del alcance del sustrato.
CO2 utilization as a chemical feedstock has been proven as a major strategy to reduce CO2 emissions to the atmosphere, and therefore to find an equilibrium in the natural carbon cycle. However, activating this stable small molecule is very challenging. In fact, high internal energy-containing reactive substrates can facilitate chemical transformations of CO2 to compensate its thermodynamic stability. Moreover, efficient catalysts are needed to overcome the high kinetic barrier of activation. Among many catalytic methods, thermal catalysis is still the mostly used method to scale up the CO2 fixation processes at industrial level. Catalysts with higher activity and selectivity in milder reaction conditions are required. Therefore, we aim to assess the efficiency of low-cost earth-abundant materials as catalysts for CO2 cycloaddition with high energy-containing epoxides. We also aim to understand the behavior of these catalysts from computational mechanistic studies, and to improve on their design corroborating with their experimental catalytic performance for this CO2 transformation reaction. In this Thesis we study three different catalysts for CO2 cycloaddition reaction with epoxides under thermal gradient. The catalysts are lignocellulosic biomasses as most abundant plant materials, 1,10-phenathronine derived four nitrogen donor containing complexes of zinc, and a cyclam derived complex of the most abundant element iron. The cooperative effects of these binary catalysts in combination of a co-catalyst, tetrabutyl ammonium bromide (TBAB) are elucidated from computational mechanistic studies. In experimental studies, the catalytic reactions are optimized for standard substrates, and %substrate conversions are corroborated with the activation energy barriers from reaction mechanisms, where applies. Also, the nature of different catalytic active sites is analyzed from substrate scope standpoint.
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Poucin, Cyprien. "Borane adsorption on MgO nanoparticles for increased catalytic activity in the cycloaddition of CO2 on epoxides". Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS142.pdf.
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La capture et la valorisation du dioxyde de carbone sont devenus des défis majeurs pour les décennies à venir. Les technologies de capture sont déjà suffisamment matures pour être mises en œuvre à l'échelle industrielle, mais les technologies de valorisation font encore défaut. Ce travail de thèse se concentre sur le développement de nouveaux catalyseurs pour la valorisation chimique du CO2. L'introduction bibliographique souligne le potentiel des oxydes alcalino-terreux pour la capture et la valorisation du CO2 en raison de leur capacité à former facilement des carbonates, ainsi que le développement récent de la chimie des Paires de Lewis Frustrées (FLP) pour l'activation de petites molécules comme le CO2. Nous y proposons une stratégie de synthèse de nanoparticules d'oxyde de magnésium fonctionnalisées avec des ligands boranes pour créer une interaction de type FLP à la surface et augmenter l'activité catalytique des nanoparticules dans la cycloaddition du CO2 sur des époxydes. Dans la première partie de ce travail, la synthèse de nanoparticules d'oxyde de magnésium par précipitation-calcination est étudiée. Les paramètres de réaction tels que la température de calcination et les lavages post-synthèse ont un impact sur la morphologie et l'état de surface des nanoparticules. La deuxième partie de ce travail se concentre sur l'adsorption de boranes sur les nanoparticules de MgO avec et sans présence de CO2. La preuve d'une interaction MgO-CO2-BPh3 est apportée par des analyses de spectroscopie infrarouge. Une interaction unique entre MgO et le chloroborane BCl2Ph est mise en évidence par un changement de couleur visuel des nanoparticules ainsi que par spectroscopie infrarouge. La dernière partie de ce travail se concentre sur l'étude catalytique de la réaction de cycloaddition. La comparaison entre les différents catalyseurs MgO confirme l'importance des paramètres de synthèse des nanoparticules sur leur activité. L'adsorption de boranes modifie l'activité et/ou la sélectivité de MgO en fonction du solvant de réaction. L'ajout de BCl2Ph augmente l'activité du catalyseur MgO d'un facteur 10 mais réduit également sa sélectivité vers la formation du carbonate cyclique. L'impact de la température, de la concentration et de la durée de la réaction sur les performances catalytiques de ce couple nanoparticule-ligand est étudié afin de dévoiler l'origine de cette synergie inédite entre MgO et BCl2PhCarbon dioxide capture and valorisation have become major challenges for the future decades. Capture technologies are already mature enough to start being implemented at industrial scale but valorisation technologies are still lacking. This thesis work focuses on the development of new catalysts for CO2 chemical valorisation. The bibliographic introduction emphasizes the potential alkaline earth oxides for CO2 capture and valorisation due to their ability to easily form carbonates, as well as the recent development of Frustrated Lewis Pair (FLP) chemistry for the activation of small molecules like CO2. We propose a strategy to synthesize magnesium oxide nanoparticles functionalised with borane ligands to create FLP-like interaction at the surface and increase the catalytic activity of the nanoparticles in the cycloaddition of CO2 on epoxides. In the first part of this work, the synthesis of magnesium oxide nanoparticles by precipitation-calcination is studied. Reaction parameters like calcination temperature and post synthesis washings are shown to impact the nanoparticles morphology and surface state. The second part of this work focuses on borane adsorption on MgO nanoparticles with and without presence of CO2. Proof of a MgO-CO2-BPh3 interaction is found using infrared spectroscopy analyses. A unique interaction between MgO and the chloroborane BCl2Ph is evidenced by a visual colour change of the nanoparticles and by infrared spectroscopy. The last part of this work focuses on the catalytic study of the cycloaddition reaction. Comparison between the different MgO catalysts confirmes the importance of the nanoparticles synthesis parameters on their activity. Adsorption of borane modifies the MgO activity and/or selectivity depending on the reaction solvent. The addition of BCl2Ph increases the activity of the MgO catalyst by a factor 10 but also reduces the selectivity toward cyclic carbonate. Impact of temperature, concentration and reaction duration on the catalytic performances of this nanoparticle¬ ligand pair is studied to unveil the origin of this unreported synergy between MgO and BCl2Ph
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Dias, Hugo. "Catalyseurs bioinspirés pour la valorisation du co2 en carbonates cycliques". Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10192.
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La valorisation du CO2 est une stratégie pouvant permettre la résolution de problématiques contemporaines. En employant comme réactif cette molécule abondante considérée comme un déchet anthropique, la mise en place de synthèses durables de produits à haute valeur ajoutée devient alors un enjeu primordial pour l’industrie chimique. La synthèse des carbonates cycliques est un exemple caractéristique d’une réaction verte convertissant du CO2 en produits d’intérêt pour l’industrie des polymères ou des batteries au lithium. Néanmoins, la cycloaddition du CO2 aux époxydes requiert l’emploi de catalyseurs sélectifs pour éviter la formation de polymères indésirables. Au sein du vivant, l’anhydrase carbonique a été largement étudiée et reconnue pour sa capacité réversible à convertir rapidement du CO2 en HCO3-. Cependant, l’application de cette métalloenzyme est proscrite à plus grande échelle en raison de son instabilité en dehors des conditions physiologiques et de son coût exorbitant. En s’inspirant de cette macromolécule dont le site actif est un complexe de zinc entouré de ligands L-histidine, l’objectif de ce travail de thèse a été de développer un système catalytique sélectif pour la synthèse des carbonates cycliques en conditions douces. Des évaluations catalytiques de sels de zinc et dérivés de L-histidine ont été effectuées et ont mené aux synthèses et caractérisations exhaustives d’une série de complexes de zinc. Leur stabilité et activité couplées à une sélectivité en carbonates cycliques a motivé une étude complémentaire afin de greffer ces complexes sur supports. Dans ce but, des silices mésoporeuses fonctionnalisées ont été préparées et leur activité catalytique testée permettant le recyclage de ces catalyseurs bioinspirés sélectifsThe CO2 valorisation is a strategy that could solve current issues. By using as a reagent this abundant molecule which is considered as an anthropogenic waste product, the development of sustainable syntheses of high added value products is becoming a key challenge for the chemical industry. The synthesis of cyclic carbonates is a typical example of a green reaction that converts CO2 into useful products for polymer and lithium battery industries. However, the CO2 cycloaddition to epoxides requires the use of selective catalysts to avoid the formation of undesirable polymers. Within living organisms, carbonic anhydrase has been widely studied and recognised for its reversible ability to rapidly convert CO2 into HCO3-. Nevertheless, the application of this metalloenzyme is prohibited for an industrial use due to its instability outside physiological conditions and its expensive cost. Inspired from this macromolecule whose active site is a zinc complex surrounded by L-histidine ligands, the aim of this thesis was to develop a selective catalytic system for the synthesis of cyclic carbonates under mild conditions. Catalytic evaluations of zinc salts and L-histidine derivatives were carried out and led to syntheses and exhaustive characterisations of a series of zinc complexes. Their stability and activity coupled with their selectivity towards cyclic carbonates prompted further researches into the grafting of those complexes onto supports. Functionalised mesoporous silicas were prepared and their catalytic activity tested, enabling those selective bioinspired catalysts to be recycled
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Balas, Matthieu. "Sustainable catalytic process for the one-pot formation of cyclic carbonates through oxidation of alkenes and CO2 cycloaddition". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS068.
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Ce projet a pour objectif la mise au point d’une réaction globale de synthèse de styrène carbonate à partir du styrène en présence de CO2 et d’un oxydant propre : O2. Les catalyseurs Salophen-R-M (R = Me2N, Et2N, tBu et M = Mn, Ni et Cr) ont été synthétisés et leur activité co-catalytique pour la réaction de cycloaddition de CO2 sur le styrène oxyde a été évaluée en présence de Bu4NBr ; Salophen-Me2N-Cr a présenté les meilleurs résultats : 99% de rendement obtenu après 3h à 80°C. Les complexes Salophen-R-M ont été greffés sur silice mésoporeuse {NH2}-SBA-15 par liaison covalente. En parallèle, le greffage de sels d’ammonium quaternaires a été optimisé par voie ex-situ sur SBA-OH. Ces matériaux catalytiques ont été testés pour la formation de styrène carbonate, avec des rendements supérieurs à ceux obtenus en solution grâce à l’effet de synergie lié à la présence de silanols. Le catalyseur Salophen-Me2N-Cr a été testé en réaction d’époxydation Mukaiyama du styrène en présence de O2 Un rendement en styrène oxyde de 50% a été obtenu dans des conditions de réaction similaires à celles utilisées en cycloaddition. La réaction globale a été effectuée en présence de catalyseurs Bu4NBr et Salophen-Me2N-Cr à 80°C sous 3,5 bar O2 et 11 bar CO2. Un rendement maximum en styrène carbonate de 31% a été obtenu après réaction en deux étapes distinctes d’oxydation (3h) puis de cycloaddition (20h)The objective of this project is to develop a comprehensive reaction for the synthesis of styrene carbonate from styrene in the presence of CO2 and a clean oxidant: O2. Salophen-R-M (R = Me2N, Et2N, tBu and M = Mn, Ni and Cr) catalysts were synthesized and their co-catalytic activity for the cycloaddition reaction of CO2 on styrene oxide was evaluated in the presence of Bu4NBr; Salophen-Me2N-Cr showed the best results: 99% yield obtained after 3h at 80°C. Salophen-R-M complexes were grafted onto mesoporous silica {NH2}-SBA-15 by covalent bonding. In parallel, the binding of quaternary ammonium salts was optimized by ex-situ grafting on SBA-OH. These catalytic materials were tested for the formation of styrene carbonate, with yields higher than those obtained in solution thanks to the synergy effect linked to the presence of silanols. The Salophen-Me2N-Cr catalyst was tested in the Mukaiyama epoxidation reaction of styrene in the presence of O2. A 50% yield of styrene oxide was obtained under reaction conditions similar to those used in cycloaddition. The overall reaction was performed in the presence of Bu4NBr and Salophen-Me2N -Cr catalysts at 80°C under 3.5 bar O2 and 11 bar CO2. A maximum yield of styrene carbonate of 31% was obtained after a two-step reaction of oxidation (3h) and cycloaddition (20h)
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Marmitt, Sandro. "Investigação mecanística de ciclios orgânicos para fixação de CO2 na presença de líquidos iônicos : uma abordagem teórico-computacional". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/134192.
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A constante emissão de CO2 na atmosfera devido a fontes antropogênica despertou uma preocupação crescente em função da sua atuação no efeito estufa. Um número crescente de metodologias para redução da concentração deste gás na atmosfera vem sendo proposta e uma alternativa atrativa é a da inserção do CO2 em anéis epóxidos para formação de carbonatos cíclicos. Apesar de já existirem inúmeros trabalhos a respeito destas reações, o mecanismo pelo qual elas ocorrem não está completamente esclarecido. Neste trabalho é apresentado o estudo mecanístico da cicloadição de CO2 em diferentes epóxidos catalisada por líquidos iônicos haletos de alquil-imidazólios, CnMIm X (n = 1, 2, 3, 4 e X = Cl, Br, I), através da Teoria do Funcional da Densidade empregando-se o funcional !B97X-D e o conjunto de base 6-31G(d,p) e LanL2DZ (somente para o I). Propuseram-se duas rotas distintas para o mecanismo, uma composta por três etapas e outra composta por somente duas etapas. Ambas as rotas tiveram a primeira etapa como sendo a mais energética e correspondendo à abertura do anel epóxido e mostraram ser competitivas entre si energeticamente. Esta etapa mostrou depender de ambos cátion e ânion do catalisador para ocorrer, onde uma ligação de hidrogênio não clássica com o H2 do imidazólio aparece no estado de transição. Verificou-se que no geral a energia de ativação da reação diminui com o aumento da cadeia alquílica do cátion imidazólio assim como diminui com o aumento do caráter nucleofílico do haleto (Cl > Br > I). O substituinte do anel epóxido também exerce influência sobre a energia de ativação da reação, porém não há uma tendência bem definida. Constatou-se que o sítio mais favorável para ataque nucleofílico é o carbono não substituído do anel epóxido tanto pela diferença de energia quanto por análise de índices de reatividade de Fukui e de interações não covalentes. Uma análise de 14 funcionais da densidade e do método perturbativo de segunda ordem MP2 em comparação ao método composto G4MP2 revelaram a forte dependência das energias de ativação com o método empregado. Através de cálculos de dinâmica molecular clássica foi possível estudar dinamicamente o sistema brometo de 1-butil-3-metil imidazólio, o óxido de estireno e o CO2 e notou-se a formação de duas fases com a presença de uma interface. Adicionalmente, observou-se que a probabilidade da reação ocorrer no bulk do líquido iônico é maior, pois a proporção catalisador/substrato é maior nesta região. Por meio da dinâmica molecular de Born-Oppenheimer constatou-se que o anel epóxido também pode ser ativado através de interações com os hidrogênios H4 e H5 do anel imidazólio.The constant emission of CO2 into the atmosphere due to anthropogenic sources has generated a growing concern regarding the greenhouse effect. Many methodologies to reduce the atmospheric CO2 concentration have been proposed and an alternative is the insertion of CO2 into epoxides to form cyclic carbonates. Although there are a lot of studies in this area, the reaction mechanism by which they occur is still unclear. In this work the cycloaddition mechanism of CO2 into different epoxides catalyzed by alkyl-imidazolium halide ionic liquids, CnMIm X (n = 1, 2, 3, 4 e X = Cl, Br, I), is presented. Density Functional Theory in conjunction with the functional !B97X-D and 6-31G(d,p) and LanL2DZ (for I atoms) basis sets were employed. Two distinct routes were proposed for the mechanism: one composed of three steps and another composed by only two steps. Both routes showed that the first step regarding the epoxide ring opening is the determined one and they are energetically competitive with each other. This step depends on both cation and anion from the catalyst to proceed through a non-classical hydrogen bond in the transition state. It was found that the activation energy decreases with the chain length of the alkyl group from the imidazolium ring as well as with the nucleophilic character of the halide (Cl > Br > I). The epoxide ring substituent also exerts influence on the activation energy of this reaction, but there is no well defined behaviour. The most favourable site for nucleophilic attack is the non-substituted epoxide ring carbon as was shown by the reaction energy difference and through reactive Fukui index and non-covalent interaction (NCI) analysis. 14 exchange-correlation density functionals were investigated and compared to the well established second order perturbation theory (MP2) method and G4MP2 composite method. One found out that the activation energies strongly depends on the chosen method. Through classical molecular dynamics it was possible to study the system 1-butyl-3-methyl-imidazolium bromide together with styrene oxide and CO2 e the formation of two phases with the presence of an interface was observed. Additionally, it was shown that the probability of the reaction to occur in the ionic liquid bulk is bigger because the catalyst/substrate proportion is bigger in this region. Born-Oppenheimer molecular dynamics was used to prove that the H4 and H5 hydrogen atoms from the imidazolium ring may interact with the oxygen atom from the epoxide and activate the C–O bond for the reaction to proceed.
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Huang, Ping-Hsuan, e 黃品瑄. "Cycloaddition of CO2 to Epoxide Catalyzed by Short-channel Amino-functionalized SBA-15". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/t52e3p.
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碩士國立臺灣大學
化學研究所
106
Carbon dioxide is one of the primary greenhouse gases which cause climate change in the past few years. Up to now, various strategies for reducing CO2 have been developed, such as carbon capture and storage. However, chemical fixation of CO2 to generate useful chemicals is a superior option. In this work, short-channel SBA-15 materials were functionalized with various amino groups, including propylamine (NH2), diamine (dia), and guanidine (gua) though one-pot method. The resultant materials were characterized by XRD, N2 sorption isotherm, TGA, SEM, EDS, FT-IR, and Solid NMR. The reaction condition of catalytic cycloaddition of CO2 to 1,2-butylene oxide was optimized by changing the reaction temperature, catalyst loading, and the CO2/epoxide ratio. The optimal yield of cyclic carbonates (1,2-butylene carbonate) determined by GC-FID was ca. 71% over 10% guanidine-functionalized SBA-15 (10%gua-Zr-SBA-15-at) at 140 °C for 18 h with CO2/epoxide ratio of 3.2. In the same condition, 48% yield of cyclic carbonate was obtained over rod 10%gua-r-SBA-15-at, implying the short channels would facilitate the diffusion of reactants into the pores of SBA-15 and access the catalytic active sites. On the other hand, the yields were only ca. 31% and 11% over 10%NH2-Zr-SBA-15-at and 10%dia-Zr-SBA-15-at, respectively, under the same reaction condition, inferring the basicity of amino-group would affect the catalytic activity. However, the yields increased to ca. 49% and 52%, respectively, over the latter amino-functional catalysts without alkaline treatment (deprotonation step). These results imply that the catalytic activity in CO2 cycloaddition to epoxide is not only related to the basicity of amino-group but also the presence of chloride counter anions on the catalyst.
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Abdullahi, Mohamed H., L. M. Thompson, M. J. Bearpark, Victoria Vinader e Kamyar Afarinkia. "The role of substituents in retro Diels-Alder extrusion of CO2 from 2(H)-pyrone cycloadducts". 2016. http://hdl.handle.net/10454/9888.
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YesAn experimental and computational investigation is conducted into the role of substituents in retro Diels-Alder extrusion of CO2 from 2-oxa-bicyclo[2.2.2]oct-5-en-3-ones. We provide the first experimental evidence that loss of CO2 from the cycloadducts significantly depends on the nature and position of the substituents. For example, we show that whilst 5-carboethoxy-2-pyrone undergoes a more facile cycloaddition that 3-carboethoxy-2-pyrone, the cycloadduct from the latter pyrone undergoes a more facile loss of CO2 than the cycloadduct from the former pyrone.
EPSRC, Yorkshire Cancer Research, Yorkshire Enterprise Fellowships
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kai, chang chun, e 張鈞凱. "The thesis aim to clarify the role of organic base, metal-salen, and heterogeneous catalyst in the cycloaddition of CO2 and epoxide". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/76440773681132402944.
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碩士中國文化大學
應用化學研究所
93
The thesis aim to clarify the role of organic base, metal- salen, and heterogeneous catalyst in the cycloaddition of CO2 and epoxide. The simplest salen-type Cr complex gave the five-membered cyclic carbonate inexcellent yield in the presence of triethylamine.
Capítulos de livros sobre o assunto "Cycloaddition du CO2"
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Szpilman, Alex M., e Erick M. Carreira. "Cycloaddition Reactions". In Silver in Organic Chemistry, 43–82. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470597521.ch2.
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Zhao, Mei-Xin, e Min Shi. "Organoamines-catalyzed Cycloadditions". In Organocatalytic Cycloadditions for Synthesis of Carbo- and Heterocycles, 25–140. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527807291.ch2.
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Pedersen, Daniel Sejer, e Andrew David Abell. "Huisgen Cycloaddition in Peptidomimetic Chemistry". In Amino Acids, Peptides and Proteins in Organic Chemistry, 99–127. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527631827.ch2.
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Kumar, Puneet, e Janis Louie. "Nickel-Mediated [2 + 2 + 2] Cycloaddition". In Transition-Metal-Mediated Aromatic Ring Construction, 37–70. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118629871.ch2.
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Hein, Jason E. "[3+2]-Dipolar Cycloadditions in Bioconjugation". In Chemoselective and Bioorthogonal Ligation Reactions, 37–66. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2017. http://dx.doi.org/10.1002/9783527683451.ch2.
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Denmark, Scott E., e Jeromy J. Cottell. "Nitronates". In Synthetic Applications of 1,3-Dipolar Cycloaddition Chemistry Toward Heterocycles and Natural Products, 83–167. New York, USA: John Wiley & Sons, Inc., 2003. http://dx.doi.org/10.1002/0471221902.ch2.
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Fernández-Rodríguez, Manuel A. "Gold-Catalyzed Intra- and Intermolecular Cycloadditions of Push-Pull Dienynes". In Ideas in Chemistry and Molecular Sciences, 25–42. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2010. http://dx.doi.org/10.1002/9783527630554.ch2.
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Intrieri, Daniela, Caterina Damiano, Paolo Sonzini e Emma Gallo. "Porphyrin-based homogeneous catalysts for the CO2 cycloaddition to epoxides and aziridines". In Porphyrin Science by Women, 1107–30. WORLD SCIENTIFIC, 2021. http://dx.doi.org/10.1142/9789811223556_0100.
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"Regioselective Syntheses of Polysubstituted Benzenes Catalyzed by Transition Metal Complexes". In Alkynes in Cycloadditions, 5–105. Chichester, UK: John Wiley & Sons Ltd, 2013. http://dx.doi.org/10.1002/9781118709313.ch2.
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Li, W.-R. "Cycloaddition Reactions". In Three Carbon-Heteroatom Bonds: Esters and Lactones; Peroxy Acids and R(CO)OX Compounds; R(CO)X, X=S, Se, Te, 1. Georg Thieme Verlag KG, 2005. http://dx.doi.org/10.1055/sos-sd-021-00165.
Texto completo da fonteTrabalhos de conferências sobre o assunto "Cycloaddition du CO2"
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Yang, Jinmin, Liping Guo, Chen Zhu, Hongmei Li e Lili Huang. "Effect of chain length on catalytic activity in quaternary ammonium halides catalyzed cycloaddition of CO2 to propylene Oxide". In 2015 4th International Conference on Sustainable Energy and Environmental Engineering. Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/icseee-15.2016.105.
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