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Auswahl der wissenschaftlichen Literatur zum Thema „C heteroatom“
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Zeitschriftenartikel zum Thema "C heteroatom"
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Wang, Jia-Qi, Zhen-Yu Zuo und Wei He. „Recent Advances of Green Catalytic System I2/DMSO in C–C and C–Heteroatom Bonds Formation“. Catalysts 12, Nr. 8 (26.07.2022): 821. http://dx.doi.org/10.3390/catal12080821.
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Developing a green, practical and efficient method for the formation of C–C and C–Heteroatom bonds is an important topic in modern organic synthetic chemistry. In recent years, the I2/DMSO catalytic system has attracted wide attention because of its green, high efficiency, atomic economy, low cost, mild reaction conditions and it is environment-friendly, which is more in line with the requirements of sustainable chemistry. Heteroatom-containing compounds have shown lots of important applications in pharmaceutical synthesis, agrochemicals, material chemistry and organic dyes. At present, the I2/DMSO catalytic system has been successfully applied to the synthesis of various heteroatom-containing compounds. The C–C and C–Heteroatom bonds have been formed efficiently, which has been proved to be a green and mild catalytic system. In this review, the research achievements of the I2/DMSO catalytic system in the formation of C–C and C–Heteroatom bonds from 2015 to date are described, and the research area is prospected. This review attempts to reveal the general law of iodine catalysis and lay a foundation for the design of new reactions.
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Skalik, Joanna, Marek Koprowski, Ewa Różycka-Sokołowska und Piotr Bałczewski. „The hetero-Friedel-Crafts-Bradsher Cyclizations with Formation of Ring Carbon-Heteroatom (P, S) Bonds, Leading to Organic Functional Materials“. Materials 13, Nr. 21 (23.10.2020): 4751. http://dx.doi.org/10.3390/ma13214751.
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The interest in functional materials possessing improved properties led to development of new methods of their synthesis, which allowed to obtain new molecular arrangements with carbon and heteroatom motifs. Two of the classical reactions of versatile use are the Friedel-Crafts and the Bradsher reactions, which in the new heteroatomic versions allow to replace ring carbon atoms by heteroatoms. In the present work, we review methods of synthesis of C–S and C–P bonds utilizing thia- and phospha-Friedel-Crafts-Bradsher cyclizations. Single examples of C–As and lack of C–Se bond formation, involving two of the closest neighbors of P and S in the periodic table, have also been noted. Applications of the obtained π-conjugated molecules, mainly as semiconducting materials, flame retardants, and resins hardeners, designed on the basis of five- and six-membered cyclic molecules containing ring phosphorus and sulfur atoms, are also included. This comprehensive review covers literature up to August 2020.
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Kadjo, François Kassi, Sopi Thomas Affi, Yao Silvère Diki N’guessan, Mamadou Guy-Richard Koné, Georges Stéphane Dembélé und Nahossé Ziao. „Theoretical Characterization of the Hydrogen Bonding Interaction Sites of Mycolactone C Using the ONIOM Method“. Mediterranean Journal of Chemistry 11, Nr. 2 (26.04.2021): 185. http://dx.doi.org/10.13171/mjc02104261574mgrk.
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<p>In this work, the ONIOM method, recognized for its effectiveness on large molecules, was used to determine the geometric, energetic, and spectroscopic parameters of hydrogen bond interactions of mycolactone C. Mycolactone C; one of the most virulent forms of toxin, found in Africa and Australia. It has eight (08) oxygen heteroatoms which are all hybridized sp<sup>2</sup> and sp<sup>3</sup>. Using quantum chemistry methods, at the ONIOM level (B3LYP/6-311+G (d, p): AM1), we have determined the preferential binding sites of the hydrogen bonds in the eight mycolactone C oxygen heteroatoms studied. Analysis of the results revealed that the heteroatom O<sub>5</sub>sp<sup>2</sup> is the most suitable site for creating a strong hydrogen bond based on the geometric, energetic (free enthalpy of complexation), and spectroscopic (vibration frequency shifts) parameters. Identifying this O5sp2 heteroatom is a significant step forward in developing a methodology for eradicating the infection and the destructive effects of this toxin.</p>
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Sharma, Mitu, Bhupendra Adhikari, Raymond Femi Awoyemi, Amanda M. Perkins, Alison K. Duckworth, Bruno Donnadieu, David O. Wipf, Sean L. Stokes und Joseph P. Emerson. „Copper(II) NHC Catalyst for the Formation of Phenol from Arylboronic Acid“. Chemistry 4, Nr. 2 (07.06.2022): 560–75. http://dx.doi.org/10.3390/chemistry4020040.
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Arylboronic acids are commonly used in modern organic chemistry to form new C–C and C–heteroatom bonds. These activated organic synthons show reactivity with heteroatoms in a range of substrates under ambient oxidative conditions. This broad reactivity has limited their use in protic, renewable solvents like water, ethanol, and methanol. Here, we report our efforts to study and optimize the activation of arylboronic acids by a copper(II) N-heterocyclic carbene (NHC) complex in aqueous solution and in a range of alcohols to generate phenol and aryl ethers, respectively. The optimized reactivity showcases the ability to make targeted C–O bonds, but also identifies conditions where water and alcohol activation could be limiting for C–C and C–heteroatom bond-forming reactions. This copper(II) complex shows strong reactivity toward arylboronic acid activation in aqueous medium at ambient temperature. The relationship between product formation and temperature and catalyst loading are described. Additionally, the effects of buffer, pH, base, and co-solvent are explored with respect to phenol and ether generation reactions. Characterization of the new copper(II) NCN-pincer complex by X-ray crystallography, HR-MS, cyclic voltammetry, FT-IR and UV-Vis spectral studies is reported.
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Zhou, Fengtao, und Qian Cai. „Recent advances in copper-catalyzed asymmetric coupling reactions“. Beilstein Journal of Organic Chemistry 11 (15.12.2015): 2600–2615. http://dx.doi.org/10.3762/bjoc.11.280.
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Copper-catalyzed (or -mediated) asymmetric coupling reactions have received significant attention over the past few years. Especially the coupling reactions of aryl or alkyl halides with nucleophiles became a very powerful tool for the formation of C–C, C–N, C–O and other carbon–heteroatom bonds as well as for the construction of heteroatom-containing ring systems. This review summarizes the recent progress in copper-catalyzed asymmetric coupling reactions for the formation of C–C and carbon–heteroatom bonds.
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Peng, Haihui, Rong Cai, Chang Xu, Hao Chen und Xiaodong Shi. „Nucleophile promoted gold redox catalysis with diazonium salts: C–Br, C–S and C–P bond formation through catalytic Sandmeyer coupling“. Chemical Science 7, Nr. 9 (2016): 6190–96. http://dx.doi.org/10.1039/c6sc01742h.
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Mamgain, Ritu, Kokila Sakthivel und Fateh V. Singh. „Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts“. Beilstein Journal of Organic Chemistry 20 (13.11.2024): 2891–920. http://dx.doi.org/10.3762/bjoc.20.243.
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Diaryliodonium salts have become widely recognized as arylating agents in the last two decades. Both, symmetrical and unsymmetrical forms of these salts serve as effective electrophilic arylating reagents in various organic syntheses. The use of diaryliodoniums in C–C and carbon–heteroatom bond formations, particularly under metal-free conditions, has further enhanced the popularity of these reagents. In this review, we concentrate on various arylation reactions involving carbon and other heteroatoms, encompassing rearrangement reactions in the absence of any metal catalyst, and summarize advancements made in the last five years.
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Kim, Jin Hee, Jong Hun Han, Jae-Hyung Wee, Go Bong Choi, Seungki Hong und Yoong Ahm Kim. „Importance of Doping Sequence in Multiple Heteroatom-Doped Reduced Graphene Oxide as Efficient Oxygen Reduction Reaction Electrocatalysts“. Applied Nano 2, Nr. 3 (07.09.2021): 267–77. http://dx.doi.org/10.3390/applnano2030019.
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Multiple heteroatom-doped graphene is of great interest for developing an efficient electrocatalyst for oxygen reduction reaction (ORR). To maximize the electrocatalytic performance of doped graphene, the competitive doping mechanism caused by the different atomic sizes of dopants should be developed. Herein, three different heteroatoms (e.g., N, P and B) are competitively introduced into reduced graphene oxide (RGO) using both single- and two-step processes. The total quantity of heteroatoms for ternary RGO synthesized using the two-step process is lower than that when using the single-step process. Higher ORR electrocatalytic activity for the two-step-synthesized RGO compared to the single-step-synthesized RGO can be explained by: (a) a high amount of P atoms; (b) the fact that B doping itself decreases the less electrocatalytic N moieties such as pyrrole and pyridine and increases the high electrocatalytic moieties such as quaternary N; (c) a high amount of B atoms itself within the RGO act as an electrocatalytic active center for O2 adsorption; and (d) a small amount of substitutional B might increase the electrical conductivity of RGO. Our findings provide new insights into the design of heteroatom-doped carbon materials with excellent electrocatalytic performance.
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Desnoyer, Addison N., und Jennifer A. Love. „Recent advances in well-defined, late transition metal complexes that make and/or break C–N, C–O and C–S bonds“. Chemical Society Reviews 46, Nr. 1 (2017): 197–238. http://dx.doi.org/10.1039/c6cs00150e.
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Beletskaya, Irina P. „Palladium catalyzed C-C and C-heteroatom bond formation reactions“. Pure and Applied Chemistry 69, Nr. 3 (01.01.1997): 471–76. http://dx.doi.org/10.1351/pac199769030471.
Der volle Inhalt der QuelleDissertationen zum Thema "C heteroatom"
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Zárate, Sáez Cayetana. „C-heteroatom bond-formation via ni-catalyzed c-o bond cleavage“. Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/401555.
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Tot i que el camp de l'acoblament creuat ha desenvolupat increïbles avenços, la gran majoria de processos encara es basen en l'ús d'halurs d'aril. No obstant, aquest tipus d’electròfils presenten una toxicitat intrínseca i, al mateix temps, la seva síntesis resulta tediosa, especialment quan es tracta d'halurs d'aril altament funcionalitzats. A causa d'això, la comunitat sintètica s'ha bolcat en la recerca d'alternatives a l'ús d'halurs d'aril en química d'acoblament creuat. Grans esforços s'han desenvolupat en la última dècada per implementar els derivats del fenol en aquest tipus de transformacions a causa de l'abundància natural i comercial d'aquests compostos i a la seva baixa toxicitat en comparació amb els organohalurs. No obstant, l'alta energia d'activació necessària per trencar els enllaços C-O ha limitat considerablement l'ús de derivats de fenol en reaccions d’acoblament creuat, sobretot si es tracta d'éters de metil. Actualment la gran majoria de mètodes basats en aquesta família d’electròfils s'utilitzen en la formació d'enllaços C-C. Altrament, gairebé no existeixen tècniques per obtenir enllaços Cheteroàtom probablement a causa de la baixa reactivitat dels nucleòfils, on la densitat de càrrega negativa resideix en un heteroàtom. La present tesi doctoral s'ha centrat en el desenvolupament de noves metodologies per a la creació d'enllaços de tipus C-heteroàtom mitjançant l’activació catalítica d'enllaços C-O amb complexes de Ni. S'han descrit nous mètodes de sililació i borilació d'ésters i metil éters
d’aril i benzil. Aquests mètodes suposen una via alternativa per a la síntesis de silans i boronats, els quals són intermedis de gran utilitat en
síntesis orgànica. A més, el descobriment d'unes condicions totalment inusuals per activar enllaços de tipus C-OMe ha obert noves
perspectives sobre la reactivitat d'aquest tipus d'enllaços i, alhora, ha suggerit l'existència de nous mecanismes d'activació.A pesar de que el campo del acoplamiento cruzado ha desarrollado increíbles avances, la gran mayoría de procesos todavía se basa en el uso de halogenuros de arilo. Sin embargo, este tipo de electrófilos presentan una toxicidad intrínseca y, a su vez, su síntesis resulta tediosa, especialmente cuando se trata de halogenuros de arilo altamente funcionalizados. Debido a ello, la comunidad sintética se ha volcado en la búsqueda de alternativas al uso de halogenuros de arilo en química de acoplamiento cruzado. Un gran esfuerzo se ha desarrollado en la última década para implementar los derivados del fenol en este tipo de transformacions debido a la abundancia natural y comercial de dichos compuestos y a su baja toxicidad en comparación con los organohalogenuros. Sin embargo, la alta energía de activación necesaría para romper los enlaces C-O ha limitado considerablemenete el uso de derivados del fenol en reacciones de acomplamineto cruzado, sobre todo si se trata de éteres de metilo. Actualmente la gran mayoría de métodos basados en esta familia de electrófilos se utilizan en la formación de enlaces C-C. De lo contrario, apenas existen técnicas para obtener enlaces C-heteroátomo probablemente debido a la baja reactividad de los nucleófilos donde la densidad de carga negativa reside en un heteroátomo. La presente tesis docotoral se ha centrado en el desarrollo de nuevas metodologías para la creación de enlaces de tipo C-heteroatomo mediante la activción catalítica de enlaces C-O con complejos de Ni. Se han descrito novedosos métodos de sililación y borilación de ésteres y metil éteres de arilo y bencilo. Dichos métodos suponen una via alternativa para la síntesis de silanos y boronatos, los cuales son intermedios de gran utilidad en síntesis orgánica. Además, el descubrimiento de unas condiciones totalmente inusuales para activar enlaces de tipo C-OMe ha abierto nuevas perspectivas sobre la reactividad de este tipo de enlaces y, a la vez, ha sugerido la existencia de nuevos mecanismos de activación.
While the field of cross-coupling has reached remarkable levels of sophistication, the vast majority of processes are still being conducted with organic halide counterparts. Drawbacks associated to their toxicity and the limited accessibility of densely functionalized aryl halides have prompted chemists to develop powerful, yet practical, alternatives. Among these, the utilization of phenol derivatives as coupling partners via C-O bond cleavage would be particularly rewarding due to their readily availability and benign nature. However, the high activation energy required for effecting C–O bond cleavage has become a daunting challenge when devising catalytic techniques using phenol derivatives, specially always-elusive aryl methyl ethers. At present, the vast majority of cross-coupling reactions using phenol derivatives remains confined to C–C bond formation, whereas the formation of C-heteroatom bonds has been poorly studied, likely due to the less reactivity of heteroatom-based nucleophiles. This doctoral thesis has focused on the development of new methodologies for forging C-heteroatom bonds via Ni-catalyzed C-O bond cleavage. It has been described new protocols for the silylation and borylation of aryl and benzyl esters and methyl ethers. These methodologies can be used as useful alternatives towards the synthesis of aryl and benzyl silanes and boronates, incredible important intermediates in organic synthesis. Furthermore, the discovery of unusual, yet surprising, conditions for the cleavage of C-OMe bonds have opened up new vistas towards the reactivity of aryl and benzyl methyls ethers while suggesting new activation pathways.
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Gu, Yiting. „C-H & C-O Functionalization by Silicon-Heteroatom Interelement Linkage“. Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668961.
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La química sintètica és gairebé inimaginable sense tres elements principals del grup, a saber, boro, silici i estany. Quan s'uneixen a un àtom de carboni de qualsevol hibridació, aquests grups funcionals serveixen de linchpins excepcionalment versàtils en síntesi, transformant-se selectivament en una enorme amplitud d'enllaços C-C i C-X, per tant, descobrir nous mètodes per forjar el valor afegit C-Si, Els enllaços C-B i C-Sn sempre tenen una gran demanda.
D'acord amb l'interès de la investigació en el grup de Martín per activar enllaços o molècules inerts, aquesta tesi doctoral se centra en el desenvolupament de noves tècniques per fer ús de l'enllaç d'interrelació de silici-heteroatoma per funcionalitzar l'enllaç C-O i C-H inerts mitjançant una catàlisi de níquel o sistema lliure de transició de metalls.
Hem desenvolupat tres nous mètodes per a la funcionalització d’enllaços C-O i C-H inerts mitjançant l’ús d’enllaços d’interrelació basats en silici. Totes les transformacions anteriors presenten un excel·lent perfil de quimioselectivitat en condicions suaus. Es duen a terme estudis i debats sobre mecanismes previs per entendre com i per què van continuar aquestes reaccions. Les transformacions realitzades contribueixen a la comprensió de l’ús més prolífic d’enllaços químics inerts en els compostos de valor afegit de síntesi. Creiem que aquests protocols contribuirienLa química sintética es casi inimaginable sin tres elementos principales del grupo, a saber, boro, silicio y estaño. Cuando se unen a un átomo de carbono de cualquier hibridación, estos grupos funcionales sirven como linchpins excepcionalmente versátiles en síntesis, transformándose selectivamente en una enorme variedad de enlaces C-C y C-X, por lo tanto, descubren nuevos métodos para forjar el valor agregado C-Si, Los bonos C-B y C-Sn siempre tienen una gran demanda. En línea con el interés de la investigación en el grupo de Martín de la activación de enlaces o moléculas inertes, esta tesis doctoral se centra en el desarrollo de nuevas técnicas para hacer uso del enlace de interelemento de silicio-heteroátomo para funcionalizar el enlace inerte C-O & C-H a través de catálisis de níquel o sistema sin transición de metal. Hemos desarrollado tres nuevos métodos para la funcionalización de enlaces inertes C-O y C-H mediante el uso de enlaces de interelemento basados en silicio. Todas las transformaciones anteriores muestran un excelente perfil de quimioselectividad en condiciones suaves. Se realizan estudios y debates mecanicistas preliminares para comprender cómo y por qué se produjeron estas reacciones. Las transformaciones realizadas contribuyen a la comprensión del uso más prolífico de enlaces químicos inertes a los compuestos de valor agregado de síntesis.
Synthetic chemistry is almost unimaginable without three main group elements, namely, boron, silicon, and tin. When attached to a carbon atom of any hybridization, these functional groups serve as exceptionally versatile linchpins in synthesis, selectively transforming into an enormous breadth of C-C and C-X bonds, thus, discover new methods to forge value added C-Si, C-B and C-Sn bonds are always in highly demand. In line with the research interest in Martín’s group of activating inert bonds or molecules, this doctoral thesis focuses on the development of novel techniques to make use of silicon-heteroatom interelement linkage to functionalize inert C-O & C-H bond via either nickel catalysis or transition metal free system. We have developed three new methods towards the functionalization of inert C-O & C-H bonds by using silicon-based interelement linkages. All the above transformations display excellent chemoselectivity profile under mild conditions. Preliminary mechanistic studies and discusses are carried out to understand how and why these reactions proceeded. The transformations realized contribute to the understanding of more prolific use of inert chemical bonds to the synthesis value added compounds. We believe these protocols would definitely contribute to a systematic utilization of silicon-heteroatom reagent in the arena of inert chemical bond functionalization.
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Tang, Renhe. „New Catalytic Process for C-Heteroatom Bond Formation“. Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10275.
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L'objectif principal de cette thèse est de concevoir de nouvelles méthodes catalytiques pour la synthèse de liaisons C-hétéroatome. Le travail est divisé en trois chapitres, chacun se concentrant sur un système catalytique et une réaction différents. Le premier chapitre explore l'utilisation du nickel en combinaison avec le xantphos comme catalyseur pour l'arylation du SeCF3 nucléophile en utilisant les triflates d'aryle comme partenaire de couplage. Ce système catalytique démontre une large applicabilité pour une variété de dérivés de triflate d'aryle. Grâce à une combinaison d'expériences stœchiométriques et d'études de la théorie fonctionnelle de la densité (DFT), le mécanisme de formation des composés trifluorométhylselenés a été élucidé. Cette investigation a fourni un aperçu des paramètres clés qui influencent la réactivité du système catalytique. Le deuxième chapitre se concentre sur le développement d'une réaction de couplage carboxylatif C-N. Nous avons rapporté un système efficace Phosphinoacridine/Pd catalysé par la lumière visible pour la synthèse de carbamates d'aryle à partir d'halogénures d'aryle, d'amines et de CO2 atmosphérique. L'étape cruciale implique le contrôle de l'état d'oxydation du catalyseur au palladium par transfert de charge métal-ligand (MLCT) pour promouvoir l'étape d'élimination réductive, facilitant ainsi la formation des carbamates d'aryle souhaités. Le troisième chapitre se concentre sur le développement d'un système efficace acridine/Ni catalysé par la lumière visible pour la synthèse d'amines aromatiques via des réactions de couplage C-N. Ce système facilite le couplage des amines primaires et secondaires, ainsi que des sulfonamides, via la formation de liaisons C-N. Le système catalytique produit systématiquement les dérivés anilines désirés avec de hauts rendements, démontrant son potentiel en tant que méthode polyvalente et robuste pour la synthèse d'amines aromatiquesThe main goal of this thesis is to design new catalytic methods for the synthesis of C-heteroatom bonds. The work is divided into three chapters, each focusing on a different catalytic system and reaction.The first chapter explores the use of nickel in combination with xantphos as a catalyst for the arylation of nucleophilic SeCF3 using aryl triflates as the coupling partner. This catalytic system demonstrates broad applicability for a variety of aryl triflate derivatives. Through a combination of stoichiometric experiments and density functional theory (DFT) studies, the mechanism of forming trifluoromethylselenated compounds was elucidated. This investigation provided insight into the key parameters that influence the reactivity of the catalytic system. The second chapter focuses on the development of a carboxylative C-N coupling reaction. We reported an efficient visible-light Phosphinoacridine/Pd-catalyzed system for synthesizing aryl carbamates from aryl halides, amines, and atmospheric CO2. The pivotal step involves controlling the oxidation state of the palladium catalyst through metal-to-ligand charge transfer (MLCT) to promote the reductive elimination step, thereby facilitating the formation of the desired aryl carbamates. The third chapter focuses on the development of an efficient visible-light acridine/Ni-catalyzed system for synthesizing aromatic amines through C-N coupling reactions. This system facilitates the coupling of primary and secondary amines, as well as sulfonamides, via C-N bond formation. The catalytic system consistently produces the desired aniline derivatives in high yields, showcasing its potential as a versatile and robust method for the synthesis of aromatic amines
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Kundu, Sekhar. „Poly ionic resins supported reagents and catalysts : applications to c c & c heteroatom bond forming reactions“. Thesis, University of North Bengal, 2012. http://hdl.handle.net/123456789/1449.
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Ahire, M. „Novel C-C and C-heteroatom bond forming synthetic strategies for the construction of potential scaffolds by NHC-catalysis and difunctionalization of arynes“. Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4547.
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Abstract: This thesis demonstrates our accomplishments in the field of N-heterocyclic carbene catalysis
and aryne chemistry to construct novel organic scaffolds. Chapter 1 is divided into three sections. Section
1 provides information on NHC catalyzed reactions, in particular, the Stetter reaction with selected
examples from literature, whereas section 2 and 3 deals with our work on N-heterocyclic carbene
catalyzed Stetter reactions of aromatic aldehydes with maleimides and N-substituted itaconimides,
respectively. The developed Stetter reactions worked well under operationally simple reaction conditions
to afford value added succinimide derivatives. Chapter 2 describes our novel work on the application of
NHC catalysis in the total synthesis of cruciferane natural product. Herein, we have developed an
intramolecular 3+2 cyloaddtion of homoenolate with imine as a key step to construct the cruciferane
scaffold. Chapter 3 is divided into three sections. Section 1 provides information on various modes of
aryne reactions and illustrates the reactivity and selectivity of aryne insertion reaction in elementalelemental
bond with the help of representative examples from the literature. Section 2 and 3 describes our
studies on aryne insertion reaction in C-C and C-S bond, respectively. Section 2 shows the preparation of
valuable ortho-methyl trifluoromethyl sulfide substituted benzophenones through aryne insertion in C-C
bond. Due to fluorine’s intrinsic property of modifying the pharmacological properties of drug molecules,
its installation in the organic molecule through aryne chemistry was our prime motive, which was achieved
successfully. Section 3 involves utilization of sulfur ylide for difunctionalization of aryne via C-S bond
insertion. This section demonstrates novel reactivity for sulfur ylides.AcSIR
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Dwivedi, Seema. „Green approaches towards transition-metal catalyzed and metal-free c - c and c - heteroatom coupling reactions“. Thesis, University of North Bengal, 2019. http://ir.nbu.ac.in/handle/123456789/3646.
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Kim, Young B. „Heteroatom insertion reactions of metal carbenoids : synthesis and biological evaluation for protein kinase C. /“. Full text available from ProQuest UM Digital Dissertations, 2008. http://0-proquest.umi.com.umiss.lib.olemiss.edu/pqdweb?index=0&did=1836404551&SrchMode=1&sid=3&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1258562682&clientId=22256.
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Thesis (Ph.D.)--University of Mississippi, 2008.Typescript. Vita. Major professor: Dr. John M. Rimoldi "November 2008." Includes bibliographical references (leaves 114-136). Also available online via ProQuest to authorized users.
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Kunchithapatham, Kamala. „Development of Calcium and Palladium Catalysts for the Formation of Carbon-Carbon and Carbon-Heteroatom Bonds“. The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337955731.
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Weber, Philip M. [Verfasser], Lukas J. [Gutachter] Gooßen, Gerald [Gutachter] Dyker und Viktoria H. [Gutachter] Däschlein-Gessner. „Katalysatoren und Liganden zur Entwicklung von C-C- und C-Heteroatom-Bindungsknüpfungen / Philip M. Weber ; Gutachter: Lukas J. Gooßen, Gerald Dyker, Viktoria H. Däschlein-Gessner ; Fakultät für Chemie und Biochemie“. Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/120156073X/34.
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Bruneau, Alexandre. „Développement de nouvelles réactions métallo-catalysées pour la création de liaisons C-C et C-hétéroatomes : Application à la synthèse d’inhibiteurs de la Hsp90 et aux ligands de la lectine A“. Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS138.
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Les travaux rapportés dans ce mémoire concernent le développement de nouvelles réactions métallo-catalysées pour la création de liaison carbone-hétéroatome et carbone-carbone ainsi que leurs applications à la synthèse de produits biologiquement actifs. La première partie de ce manuscrit est consacrée à l'étude de la réactivité des sucres dans les couplages organométalliques. Des conditions ont été développées pour la création de la liaison C-S entre glycosyl thiols et partenaires arylés. De plus, la création de la liaison carbone azote de glycosyl amines avec des acides boroniques a été étudiée. Les produits synthétisés dans cette première partie ont été évalués pour leur potentiel d'inhibition de la Lectine A chez Pseudomonas aeruginosa, impliquée dans de sévères infections pulmonaires.La seconde partie de ce travail est dédiée à la création d'une série inédite d'analogues du 6BrCaQ, inhibiteurs de la Hsp90 ainsi que leur évaluation biologique. Cette nouvelle série est obtenue grâce à une nouvelle méthodologie de synthèse basée sur l'activation C-H entre un hétérocycle halogéné et son partenaire C-H activable. L'activité antiproliférative et l'inhibition de la Hsp90 ont été évaluées et seront présentées dans ce manuscritThe work reported in this dissertation concerns the development of new metal-catalyzed reactions for the creation of carbon-heteroatom and carbon-carbon bonds as well as their applications to the synthesis of biologically active products.The first part of this manuscript is devoted to the study of the reactivity of sugars as nucleophiles in organometallic couplings. Conditions were developed for the creation of the C-S bond between glycosyl thiols and aryl partners. Moreover, the creation of the nitrogen carbon bond of glycosyl amine with boronic acids was studied. The products synthesized in this first part have been evaluated for their potential to inhibit the lectin A, in Pseudomonas aeruginosa related lung infections.The second part of this work is dedicated to the creation of a new series of 6BrCaQ analogues as Hsp90 inhibitors and their biological evaluation. This new series was synthetized through a new CH activation methodology. The antitumoral potential was evaluated and will be presented in this manuscript
Bücher zum Thema "C heteroatom"
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Mermer, Arif, Neslihan Demirbas und Ahmet Demirbas. Green Methodologies Leading to the Formation of New C-C and C-Heteroatom Bonds. Cambridge Scholars Publishing, 2022.
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Carreira, Erick M., Carl P. Decicco, John P. Wolfe, Mats Larhed und Alois Fürstner. Cross-Coupling and Heck-Type Reactions 2: Carbon-Heteroatom Cross Coupling and C-C Cross Couplings of Acidic C-H Nucleophiles. Thieme Medical Publishers, Incorporated, 2013.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "C heteroatom"
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Koser, Gerald F. „C-Heteroatom-Bond Forming Reactions“. In Hypervalent Iodine Chemistry, 137–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-46114-0_5.
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Bonne, Damien, Thierry Constantieux, Yoann Coquerel und Jean Rodriguez. „Cascade Reactions Forming Both C-C Bond and C-Heteroatom BOND“. In Stereoselective Organocatalysis, 559–85. Hoboken, New Jersey: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118604755.ch16.
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Nikitas, Nikolaos F., und Christoforos G. Kokotos. „C–C and C–Heteroatom bonds photocatalyzed and photoinitiated by carbonyls“. In Photochemistry, 270–91. Cambridge: Royal Society of Chemistry, 2021. http://dx.doi.org/10.1039/9781839165269-00270.
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Terada, M. „Heteroatom—Heteroatom Double Bonds as Enophiles“. In Stereoselective Pericyclic Reactions, Cross Coupling, and C—H and C—X Activation, 1. Georg Thieme Verlag KG, 2011. http://dx.doi.org/10.1055/sos-sd-203-00209.
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Echavarren, A. M., und S. Porcel. „C—C Bond-Forming Reactions“. In Quinones and Heteroatom Analogues, 1. Georg Thieme Verlag KG, 2006. http://dx.doi.org/10.1055/sos-sd-028-00530.
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Davies, H. M. L., und D. Morton. „Heteroatom-Directed C—H Functionalization“. In Stereoselective Pericyclic Reactions, Cross Coupling, and C—H and C—X Activation, 1. Georg Thieme Verlag KG, 2011. http://dx.doi.org/10.1055/sos-sd-203-00354.
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Lambert, Tristan H. „Asymmetric C–Heteroatom Bond Formation“. In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0036.
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Tomislav Rovis at Colorado State University developed (Angew. Chem. Int. Ed. 2012, 51, 5904) an enantioselective catalytic cross-aza-benzoin reaction of aldehydes 1 and N-Boc imines 2. The useful α-amido ketone products 4 were configurationally stable under the reaction conditions. In the realm of asymmetric synthesis, few technologies have been as widely employed as the Ellman chiral sulfonamide auxiliary. Francisco Foubelo and Miguel Yus at the Universidad de Alicante in Spain have adapted (Chem. Commun. 2012, 48, 2543) this approach for the indium-mediated asymmetric allylation of ketimines 5, which furnished amines 6 with high diastereoselectivity. There has been vigorous research in recent years into the use of NAD(P)H surrogates, especially Hantzsch esters, for biomimetic asymmetric hydrogenations. Yong-Gui Zhou at the Chinese Academy of Sciences showed (J. Am. Chem. Soc. 2012, 134, 2442) that 9,10-dihydrophenanthridine (10) can also serve as an effective “H2” donor for the asymmetric hydrogenation of imines, including 7. Notably, 10 is used catalytically, with regeneration occurring under mild conditions via Ru(II)-based hydrogenation of the phenanthridine 11. A unique approach for asymmetric catalysis has been developed (Nature Chem. 2012, 4, 473) by Takashi Ooi at Nagoya University, who found that ion-paired complexes 14 could serve as effective chiral ligands in the Pd(II)-catalyzed allylation of α-nitrocarboxylates 12. The resulting products 13 are easily reduced to furnish α-amino acid derivatives. Another novel catalytic platform has been employed (J. Am. Chem. Soc. 2012, 134, 7321) for the chiral resolution of 1,2-diols 15 by Kian L. Tan at Boston College. Using the concept of reversible covalent binding, the catalyst 16 was found to selectively silylate a secondary hydroxyl over a primary one, thus leading to the enantioenriched products 17 and 18. Scott E. Denmark at the University of Illinois has applied (Angew. Chem. Int. Ed. 2012, 51, 3236) his chiral Lewis base strategy to the enantioselective vinylogous aldol reaction of N-silyl vinylketene imines 19 to produce γ-hydroxy-α,β-unsaturated nitriles 22. For the preparation of enantioenriched homopropargylic alcohols 25, the asymmetric addition of allenyl metal nucleophiles (e.g., 24) to aldehydes 23 provides a straightforward approach.
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Jack Li, Jie. „Without C—C Bond Cleavage“. In Heteroatom Analogues of Aldehydes and Ketones, 1. Georg Thieme Verlag KG, 2004. http://dx.doi.org/10.1055/sos-sd-027-00441.
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Jack Li, Jie. „With C—C Bond Cleavage“. In Heteroatom Analogues of Aldehydes and Ketones, 1. Georg Thieme Verlag KG, 2004. http://dx.doi.org/10.1055/sos-sd-027-00449.
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„C–X Bond Formation“. In Biocatalysis in Organic Synthesis: The Retrosynthesis Approach, 179–216. The Royal Society of Chemistry, 2018. http://dx.doi.org/10.1039/bk9781782625308-00179.
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This chapter covers enzyme classes that are capable of catalysing reactions to form carbon–heteroatom bonds, including transaminases, ammonia lyases, hydratases, halohydrin dehalogenases and methyltransferases. The chapter is divided into separate sections, each detailing the formation of a specific carbon–heteroatom bond, including carbon–nitrogen, carbon–oxygen, carbon–halogen and carbon–sulfur bonds. Each section begins with a review of chemical methods of making each bond type, followed by a description of the enzyme classes capable of catalysing each bond formation. The substrate scope of each enzyme class, including its chemo-, regio- and stereoselectivity, is discussed and a general mechanism for the enzyme-catalysed reaction is presented. Where appropriate, strategies for co-factor recycling are also included. This should give the reader a rounded understanding of when and how to carry out C–X bond forming reactions using enzymes.
Konferenzberichte zum Thema "C heteroatom"
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Mikhailova, Anastasia N., Shadi A. Saeed, Muneer A. Suwaid, Ameen A. Al-Muntaser, Xiaodong Zhou, Dmitriy A. Feoktistov, Dmitrii A. Emelyanov, Mikhail A. Varfolomeev, Vladimir P. Morozov und Evgeniya V. Morozova. „The Influence of Individual Solvents as Hydrogen Donors on the Hydrothermal Conversion of Organic Matter in Shale Rocks of Domanik Deposits“. In SPE Europe Energy Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/220047-ms.
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Abstract The influence of individual solvents (ethyl acetate and tetralin) as hydrogen donors on the nature of the conversion of organic matter of low-permeable shale Domanik rock from the Mendym deposits of the Upper Devonian of the Tavel deposit (Tatarstan, Russia) during hydrothermal processes was studied. The experiments were carried out at a temperature of 300°C in a CO2 environment with a water content in the reaction system of a 1:1 to sample of rock and an exposure time of 24 hours. The degree of conversion of kerogen into extractable hydrocarbons was determined by Rock-Eval and thermal analysis methods. The changes in the composition of the formed hydrocarbons were evaluated using different technic such as gas chromatography (GC) analysis of evolved gasses, SARA analysis, GC-MS of saturated and aromatic hydrocarbons) and elemental analysis before and after hydrothermal experiments. The results showed that, ethyl acetate does not exhibit the properties of a hydrogen proton donor but intensifies the destruction of kerogen. The results of GC-MS showed that, the ethyl acetate almost completely decomposes to acetic acid, which, in turn, due to its effect on the carbonate component of the rock, promotes the extraction of high-molecular components associated with the rock and the destruction of kerogen along the least stable C-S bonds. This is demonstrated by a higher presence of H2S in the gas composition compared to the control hydrothermal experiment. Additionally, there's an increase in the yield of extract from the rock, along with a higher content of high molecular weight components, consequently raising the sulfur content and the abundance of benzothiophenes in the aromatic fraction. Under these experimental conditions, tetralin not only enhances the conversion of organic matter from the Domanik rock into extractable hydrocarbons but also facilitates the removal of heteroatomic compounds by transferring hydrogen donors, which inhibit radical reactions. This leads to the elimination of alkyl substituents and the formation of lower molecular weight hydrocarbons. The results of GC-MS measurements of the aromatic hydrocarbons obtained confirm these processes. Specifically, a comparison with the control experiment reveals the formation of 1,4-dihydronaphthalene, naphthalene, and 1-, 2-methylnaphthalene in the composition. In addition, tetralin is not completely converted under these conditions and partially remains in the extract, also acting as a diluent, which can facilitate easier transportation of the extracted oil. The utilization of tetralin during hydrothermal treatment of kerogen-containing Domanik rock leads to several notable outcomes. Firstly, there is an increase in the yield of hydrocarbon gases. Additionally, the yield of oil extract rises, marked by more than a two-fold increase in the content of saturated hydrocarbons. Furthermore, there is a notable reduction in the content of resins by 1.5 times and a three-fold decrease in benzothiophenes within the aromatic fraction. Moreover, the presence of dibenzothiophenes is not detected, and the extract exhibits the lowest total sulfur content compared to all conducted experiments.
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Taylor, P. N., E. Tegelaar, A. S. Al Belushi und B. Al Fazari. „Understanding Oil Quality Variability In A Carbonate Reservoir Of Oman“. In ADIPEC. SPE, 2024. http://dx.doi.org/10.2118/222428-ms.
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Abstract Oil columns within carbonate reservoirs may show very large differences in petroleum fluid compositions, which presents a challenge to reservoir characterization, appraisal, development and production. A single carbonate reservoir in Oman contains oil of highly variable quality; with API gravities between 12 and 25 degrees and dead oil viscosities between 32 cP to 2,480 cP at reservoir temperature. Furthermore, oil samples collected at different times from individual wells also showed variability in their physical properties. An improved understanding of the causes of the observed variability was needed to support production operations and to assist well placement and field development strategy & optimization. Thirteen wellhead oil samples were analysed at different laboratories to determine dead oil viscosity and API gravity, and a sub-set of oils representing the range of observed oil quality was then selected for analysis by multiple methods to characterize the full boiling range of the fluids – from volatile gasoline range hydrocarbons to heavy polar fractions. Relationships between physical properties of oils and their molecular composition were used to determine the causes of the observed variability and construct a conceptual model that can form a basis for fluid quality prediction. The physical properties of the oils appeared to be directly related to the concentrations of asphaltenes and resins which, in turn, were controlled by differences in thermal maturity. There was no evidence for biodegradation in the oil geochemistry results, despite a present-day reservoir temperature of approximately 70°C. A model is proposed in which the reservoir was initially charged with heavy asphaltenic oil that was expelled from a nearby Huqf source rock in the earliest part of the oil window. Further burial and maturation of the source rock resulted in progressively lighter and less viscous oils being expelled into the carrier system. Each migrating oil pulse, with lower density and greater buoyancy than the previous one, would migrate to the top of the trap, where it displaced the earlier charge downward. Such a model can explain the range of fluid properties observed, and the general pattern of decreasing oil quality with increasing reservoir depth and is consistent with charge models observed in other carbonate fields worldwide. Lateral variations in the vertical gradients derive from proximity to reservoir charging points, impediments to lateral fluid flow caused by structural compartmentalization or reservoir facies and potentially by localized fracture zones. The abundant non-hydrocarbon content of the oils, which control physical properties, is also responsible for the tendency of the oils to form extremely stable water-in-oil emulsions due to the presence of heteroatomic functional groups. Such emulsions contributed to significant measurement uncertainty in oil density and viscosity. A robust proxy for oil density and dead oil viscosity was developed using SARA-type bulk compositional analysis. This may be used to assess fluid property variability from analysis of both oils and reservoir rock samples and has the benefit of being unaffected by the presence of water. The ability to generate data from rock samples makes it possible to create high resolution maps of oil properties via analysis of cuttings samples collected along lateral well bores.