Bibliografias temáticas / Dearomatization

Índice

Artigos de revistas
Teses / dissertações
Livros
Capítulos de livros
Trabalhos de conferências

Literatura científica selecionada sobre o tema "Dearomatization"

Autor: Grafiati

Publicado: 4 de junho de 2021

Última modificação: 7 de julho de 2024

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos

Selecione um tipo de fonte:

Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "Dearomatization".

Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.

Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.

Artigos de revistas sobre o assunto "Dearomatization"

Zheng, Hanliang, e Xiao-Song Xue. "Recent Computational Studies on Mechanisms of Hypervalent Iodine(III)-Promoted Dearomatization of Phenols". Current Organic Chemistry 24, n.º 18 (18 de novembro de 2020): 2106–17. http://dx.doi.org/10.2174/1385272824999200620223218.

Texto completo da fonte

Resumo:

Hypervalent iodine-promoted dearomatization of phenols has received intense attention. This mini-review summarizes recent computational mechanistic studies of phenolic dearomatizations promoted by hypervalent iodine(III) reagents or catalysts. The first part of this review describes mechanisms of racemic dearomatization of phenols, paying special attention to the associative and dissociative pathways. The second part focuses on mechanisms and selectivities of diastereo- or enantio-selective dearomatization of phenols.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Zeidan, Nicolas, e Mark Lautens. "Migratory Insertion Strategies for Dearomatization". Synthesis 51, n.º 22 (26 de agosto de 2019): 4137–46. http://dx.doi.org/10.1055/s-0037-1611918.

Texto completo da fonte

Resumo:

Development of strategies for molecule functionalization by dearomatization has surged in the last two decades. The benefits of overcoming the resonance stabilization energy outweigh the cost; diverse compounds could be accessed in a short number of steps. One approach that has been of interest in recent years is the dearomatization of indoles and other (hetero)aromatic compounds by migratory insertion. The chiral σ-bond palladium intermediate could be reduced or trapped by a second functionalization. In this short review we will summarize the recently discovered reactions from our group and others in this field of metal-catalyzed dearomatizations by migratory insertion.1 Introduction2 Monofunctionalizations: Heck and Reductive Heck Reactions2.1 N-Tethered Heterocycles2.2 Non-N-tethered Heterocycles2.3 Non-heterocycles3 Dearomative Difunctionalizations: Interrupted Heck Reaction3.1 N-Tethered Heterocycles3.2 Non-N-tethered Heterocycles4 Conclusion

Estilos ABNT, Harvard, Vancouver, APA, etc.

Segovia, Claire, Pierre-Antoine Nocquet, Vincent Levacher, Jean-François Brière e Sylvain Oudeyer. "Organocatalysis: A Tool of Choice for the Enantioselective Nucleophilic Dearomatization of Electron-Deficient Six-Membered Ring Azaarenium Salts". Catalysts 11, n.º 10 (18 de outubro de 2021): 1249. http://dx.doi.org/10.3390/catal11101249.

Texto completo da fonte

Resumo:

Nucleophilic dearomatization of azaarenium salts is a powerful strategy to access 3D scaffolds of interest from easily accessible planar aromatic azaarene compounds. Moreover, this approach yields complex dihydroazaarenes by allowing the functionalization of the scaffold simultaneously to the dearomatization step. On the other side, organocatalysis is nowadays recognized as one of the pillars of the asymmetric catalysis field of research and is well-known to afford a high level of enantioselectivity for a myriad of transformations thanks to well-organized transition states resulting from low-energy interactions (electrostatic and/or H-bonding interactions…). Consequently, in the last fifteen years, organocatalysis has met great success in nucleophilic dearomatization of azaarenium salts. This review summarizes the work achieved up to date in the field of organocatalyzed nucleophilic dearomatization of azaarenium salts (mainly pyridinium, quinolinium, quinolinium and acridinium salts). A classification by organocatalytic mode of activation will be disclosed by shedding light on their related advantages and drawbacks. The versatility of the dearomatization approach will also be demonstrated by discussing several chemical transformations of the resulting dihydroazaarenes towards the synthesis of structurally complex compounds.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Pu, Qian, Mingming Huo, Guojuan Liang, Lijuan Bai, Genhui Chen, Hongjiao Li, Peng Xiang, Hui Zhou e Jing Zhou. "Divergent oxidative dearomatization coupling reactions to construct polycyclic cyclohexadienones". Chemical Communications 58, n.º 27 (2022): 4348–51. http://dx.doi.org/10.1039/d2cc00183g.

Texto completo da fonte

Resumo:

Divergent oxidative dearomatization coupling reactions, in which the chemoselectivity is controlled by catalysts and bases, are reported. Our method marks a novel copper- and palladium-catalyzed C–H oxidative dearomatization of phenolic derivatives.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Shi, Lili, Wenge Zhang, Shou Chen, Lele Lu, Rong Fan, Jiajing Tan e Chao Zheng. "The Role of Ortho-dearomatization Reaction in Constructing Spirocyclic Scaffolds with an All-carbon Ring Junction". Current Organic Synthesis 15, n.º 7 (16 de outubro de 2018): 904–23. http://dx.doi.org/10.2174/1570179415666180720110051.

Texto completo da fonte

Resumo:

Background: Spiro skeleton is an important structural motif in natural products, usually accounting for their formidable architectures and remarkable biological profiles. Recent advances demonstrated that a diverse range of scenarios held the promise for the assembly of spirocenter based on ortho-dearomatization strategy. In this article, we describe the latest development of ortho-dearomatization reaction in constructing spirocyclic scaffolds with an all-carbon ring junction from a methodological standpoint. Objective: The review focuses on recent progress in the area of ortho-dearomatization reaction in constructing spirocyclic scaffolds with an all-carbon ring junction. Conclusion: In summary, we have summarized the capability of ortho-dearomatization reaction to construct spirocyclic skeleton, a common structural pattern found at the core of numerous natural products with broad structural diversities and important bioactivities. Success in this area will benefit not only the area of synthetic chemistry through methodological development, but also medicinal chemistry and chemical biology by providing access to rapid assembly of bioactive compounds’ core scaffolds.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Ismayilova, Sabira Sabir, e Sabir Qarsh Amirov. "Dearomatization of the Kerosene Fraction: Kinetic Studies". Catalysis Research 2, n.º 2 (9 de janeiro de 2022): 1. http://dx.doi.org/10.21926/cr.2202017.

Texto completo da fonte

Resumo:

The kinetics of dearomatization of a kerosene fraction processed using a zeolite catalyst (0.9 HZSM-5) at different temperatures (160-200°C), the molar ratio between the aromatic hydrocarbons present in the kerosene fraction and n-decene (1:(0.5-4)), and the reaction time (1-3 h) were studied. Based on the obtained data, a kinetic model for kerosene dearomatization is proposed. It is assumed that the single-center Riedel mechanism is followed. The stage associated with the interaction between n-decene adsorbed on the surface of the catalyst containing aromatic compounds and n-decene present in the volume is identified as the limiting sage of the dearomatization process.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Vincent, Guillaume, Hussein Abou-Hamdan e Cyrille Kouklovsky. "Dearomatization Reactions of Indoles to Access 3D Indoline Structures". Synlett 31, n.º 18 (24 de junho de 2020): 1775–88. http://dx.doi.org/10.1055/s-0040-1707152.

Texto completo da fonte

Resumo:

This Account summarizes our involvement in the development of dearomatization reactions of indoles that has for origin a total synthesis problematic. We present the effort from our group to obtain 3D-indolines scaffold from the umpolung of N-acyl indoles via activation with FeCl3 to the oxidative spirocyclizations of N-EWG indoles and via the use of electrochemistry.1 Introduction2 Activation of N-Acyl Indoles with FeCl3 2.1 Hydroarylation of N-Acyl Indoles2.2 Difunctionalization of N-Acyl Indoles3 Radical-Mediated Dearomatization of Indoles for the Synthesis of Spirocyclic Indolines4 Electrochemical Dearomatization of Indoles4.1 Direct Electrochemical Oxidation of Indoles4.2 Indirect Electrochemical Oxidation of Indoles5 Conclusion

Estilos ABNT, Harvard, Vancouver, APA, etc.

Ma, Chun, Ting Zhang, Jia-Yu Zhou, Guang-Jian Mei e Feng Shi. "Catalytic asymmetric chemodivergent arylative dearomatization of tryptophols". Chemical Communications 53, n.º 89 (2017): 12124–27. http://dx.doi.org/10.1039/c7cc06547g.

Texto completo da fonte

Resumo:

The first catalytic asymmetric arylative dearomatization of tryptophols has been established. By using quinone imine ketals as aryl group surrogates and modulating the reaction conditions, the cascade reaction of tryptophols with quinone imine ketals afforded two series of arylative dearomatization products in generally high yields, and excellent diastereo- and enantioselectivities.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Liu, Jiarun, Jiancheng Huang, Kuiyong Jia, Tianxing Du, Changyin Zhao, Rongxiu Zhu e Xigong Liu. "Direct Oxidative Dearomatization of Indoles with Aromatic Ketones: Rapid Access to 2,2-Disubstituted Indolin-3-ones". Synthesis 52, n.º 05 (28 de novembro de 2019): 763–68. http://dx.doi.org/10.1055/s-0039-1691528.

Texto completo da fonte

Resumo:

A metal-free oxidative dearomatization of indoles with aromatic ketones mediated by TEMPO oxoammonium salt is described. The dearomatization proceeds smoothly and displays a broad substrate scope with respect to both indoles and aromatic ketones in the presence of H2SO4, affording the corresponding 2,2-disubstituted indolin-3-ones in good yields.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wengryniuk, Sarah E., e Xiao Xiao. "Recent Advances in the Selective Oxidative Dearomatization of Phenols to o-Quinones and o-Quinols with Hypervalent Iodine Reagents". Synlett 32, n.º 08 (14 de janeiro de 2021): 752–62. http://dx.doi.org/10.1055/s-0037-1610760.

Texto completo da fonte

Resumo:

Abstract ortho-Quinones are valuable molecular frameworks with diverse applications across biology, materials, organic synthesis, catalysis, and coordination chemistry. Despite their broad utility, their synthesis remains challenging, in particular via the direct oxidation of readily accessible phenols, due to the need to affect regioselective ortho oxidation coupled with the sensitivity of the resulting o-quinone products. The perspective looks at the emergence of I(V) hypervalent iodine reagents as an effective class of oxidants for regioselective o-quinone synthesis. The application of these reagents in regioselective phenol oxidation to both o-quinones and o-quinols will be discussed, including a recent report from our laboratory on the first method for the oxidation of electron-deficient phenols using a novel nitrogen-ligated I(V) reagent. Also included are select examples of total syntheses utilizing this methodology as well as recent advancements in chiral I(V) reagent design for asymmetric phenol dearomatization.1 Introduction2 I(V): Hypervalent Iodine Reagents3 I(V)-Mediated Dearomatization to o-Quinones4 Bisnitrogen-Ligated I(V) Reagents: ortho Dearomatization of Electron-Poor Phenols5 I(V)-Mediated Dearomatization to o-Quinols6 Conclusion and Outlook

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Teses / dissertações sobre o assunto "Dearomatization"

Jain, Nikita. "Chiral hypervalent iodine mediated enantioselective oxidative dearomatization of naphthols". Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62521.

Texto completo da fonte

Resumo:

This dissertation investigates and describes the hypervalent iodine mediated dearomatization of naphthols, thereby yielding diversity of spiro-heterocyclic compounds in both racemic and chiral form. The first part of this thesis discloses the synthesis of racemic spiropyrrolidines and spirolactams via oxidative amidation of corresponding naphtholic sulfonamides, employing DIB as the oxidant. Enantioselective variant of the same have been demonstrated by using in situ generated chiral hypervalent iodine to provide chiral spiropyrrolidines. A noteworthy side reaction discovered in the course of these studies is the asymmetric oxidative addition of meta-chlorobenzoic acid to the naphtholic sulfonamides. The resulting acyloxylated adducts were formed with a greater degree of asymmetric induction compared to spiropyrrolidines in the same reaction mixture. Based on the results obtained from optimization study and substrate scope, plausible mechanistic insights of both cyclization and acyloxylation reactions have been provided. The second part of this thesis unravels the spiroetherification of naphtholic alcohols, thereby yielding spiroethers both in racemic and chiral form. Chiral hypervalent iodine reagents generated in situ provided a range of spiroethers with excellent ee’s and high yields. These chiral oxidants have been evaluated for kinetic resolution of naphtholic primary alcohols bearing stereogenic center at β-position in the side chain.
Science, Faculty of
Chemistry, Department of
Graduate

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wu, Ju. "Electrochemical and Non-electrochemical Oxidative Dearomatization Reactions of Indoles". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS368.

Texto completo da fonte

Resumo:

L'électrochimie est apparue comme un puissant outil de synthèse durable en chimie organique, qui évite l'utilisation d'un oxydant stoechiométrique externe et permet le développement de méthodes de difonctionnalisation très efficaces et sélectives des indoles dans des conditions douces. L'utilisation de médiateurs redox pour réaliser l'électrolyse indirecte a gagné en importance ces dernières année, ce qui offre de nombreux avantages par rapport à l'électrolyse directe. Les réactions de désaromatisation des hétéroarènes achiraux, et en particulier des indoles, donnent des structures tridimensionnelles d’un grand intérêt pour la synthèse totale ou la découverte de médicaments, via la génération de deux centres stéréogéniques contigus. Ainsi des efforts de synthèse intensifs ont été consacrés à la difonctionnalisation désaromatisante d’indoles. Dans ce contexte, le développement de réactions de désaromatisation des indoles a été étudié au cours de cette thèse. Dans la première partie de la thèse, une diallylation désaromatisante de N-acylindoles médiée par FeCl₃ a été développée pour obtenir des indolines tridimensionnelles sélectives possédant deux centres stéréogéniques contigus. Dans ce procédé, deux groupes allyle ont été introduits sur des N-acylindoles avec de l'allyltriméthylsilane en présence de FeCl₃, conduisant à la formation de deux liaisons carbone-carbone et de deux centres stéréogéniques contigus. La stéréosélectivité de cette transformation est contrôlée par la substitution du noyau indole. Des applications synthétiques ont permis d'obtenir des squelettes trans-tétrahydrocarbazoles et aza[4.4.3]propellanes par RCM. L'hydratation sélective de l'un des groupes allyliques a également été réalisée. Dans la deuxième partie de la thèse, une désomatisation oxydante directe des indoles a été réalisée par électrochimie, conduisant à des 2,3-dialcoxy ou des 2,3-diazido indolines avec une cellule non divisée à courant constant. Cette difonctionnalisation électrochimique des indoles évite l'utilisation d'un oxydant externe et présente une excellente compatibilité de groupes fonctionnels, ce qui devrait inspirer le développement d'autres réactions de désaromatisation afin d'accéder à des architectures à haute valeur ajoutée à partir de matériaux de départ facilement disponibles. Sur la base de l'étude mécanistique, nous pensons que la formation des deux liaisons C-O ou C-N résulte de l'oxydation des indoles en un intermédiaire radical cation. Dans la troisième partie de la thèse, une désaromatisation oxydante par électrolyse indirecte des indoles a été conçue en utilisant MgBr₂ comme médiateur redox pour éviter l'oxydation directe du noyau indole à l'anode. L’oxydation de l’indole en un ion bromonium induite par la génération d’un réactif électrophile bromé à partir de MgBr₂, conduit à des réactions de dihydroxylation, d’hydroxycyclisation et de bromocyclisation d’indoles. Aucun sous-produit organique n'est généré avec ce protocole qui ne nécessite aucun électrolyte supplémentaire. L’intérêt de cette transformation est démontré par les applications synthétiques
Electrochemistry emerged as a powerful sustainable synthetic tool in organic chemistry, which avoids the use of an external stoichiometric oxidant and enables the development of methods for the highly efficient and selective difunctionalization of indoles in mild conditions. The use of redox mediators to achieve indirect electrolysis is attaining increased significance, which offers many advantages compared to direct electrolysis. Dearomatization reactions of achiral heteroarenes and in particular of indoles, afford three-dimensional structures of high interest for total synthesis or drug discovery, through the generation of two contiguous stereogenic centers. Intensive synthetic efforts have been devoted to dearomative difunctionalization of indoles. In this context, the development of dearomatization reactions of indoles has been studied in this thesis. In the first part of the thesis, a dearomative diallylation of N-acylindoles mediated by FeCl₃ was developed to obtain selectively three-dimensional indolines possessing two contiguous-stereogenic centers. In this process, two allyl groups were introduced to N-acylindoles with allyltrimethylsilane in the presence of FeCl₃, leading to the formation of two carbon-carbon bonds and two contiguous-stereogenic centers. The stereoselectivity of this transformation is controlled by the substitution of the indole nucleus. Synthetic application allowed to obtain trans-tetrahydrocarbazoles and aza[4.4.3]propellane scaffolds by RCM. Selective hydration of one of the allyl group was achieved. In the second part of the thesis, a direct oxidative dearomatization of indoles was performed with electrochemistry, leading to 2,3-dialkoxy or 2,3-diazido indolines under undivided cell conditions at a constant current. This general difunctionalization of indoles avoids the use of an external oxidant and displays excellent functional group compatibility, which should inspire the development of other dearomatization reactions to access high added-value architectures from readily available starting materials. Based on the mechanistic study, the formation of the two C-O or C-N bonds is believed to arise from the oxidation of the indoles into radical cation intermediates. In the third part of the thesis, an indirect oxidative dearomatization of indoles was devised by using MgBr₂ as the redox mediator to avoid the direct oxidation of the indole nucleus at the anode. The oxidation of the indole into a bromonium ion induced by the generation of an electrophilic bromine reagent from MgBr₂, and lead to dihydroxylation, hydroxycyclization and bromocyclization reactions of indoles. No organic byproducts are generated with this protocol which requires no additional electrolyte. The potential of this transformation is demonstrated by synthetic applications

Estilos ABNT, Harvard, Vancouver, APA, etc.

Pace, Robert David Matthew. "Catalytic enantioselective dearomatization and studies towards the total synthesis of (-)-morphine". Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611683.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Garnier, Tony. "Désaromatisation oxydante asymétrique de phénols : développements méthodologiques et application à la synthèse de la scyphostatine". Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14160/document.

Texto completo da fonte

Resumo:

Les réactifs iodés hypervalents (i.e. iodanes) et les complexes métalliques en milieu oxydant sont des outils particulièrement efficaces pour réaliser la réaction de désaromatisation oxydante de phénols et donner ainsi accès à des motifs cyclohexa-2,4-diénone. Ces travaux de thèse ont permis d'étudier le développement de versions asymétriques de cette réaction de désaromatisation contrôlée soit par le substrat dans le cas de l’utilisation d’iodanes, soit par le réactif lorsqu’un complexe métal/ligands chiraux est privilégié. Cette méthodologie a ensuite été appliquée à la synthèse de la (+)-scyphostatine, un inhibiteur naturel de la sphingomyélinase neutre
Abstract

Estilos ABNT, Harvard, Vancouver, APA, etc.

Vitaku, Edon, e Edon Vitaku. "Strategic Oxidative Dearomatization - Rearomatization Cascades in the Synthesis of Aromatic and Heteroaromatic Synthons". Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621360.

Texto completo da fonte

Resumo:

Four new synthetic methods employing an oxidative dearomatization - rearomatization strategy are presented. In Chapter 2, a new oxidative dearomatization - radical cyclization - rearomatization approach to form fused oxygen-containing heterocycles is presented. Origins, design, reaction, and optimizations are discussed. In Chapter 3, meta-selective alkylation of catechol mono-ethers is described employing an oxidative dearomatization - radical addition - rearomatization approach using trialkylboranes as source of alkyl radicals. In Chapter 4, a metal-free method to synthesize fluorinated indoles from aniline starting materials is described. Chapter 5 lays the groundwork for para-selective functionalization of catechol mono-ethers. Chapters 6 and 7 highlight the work related to pharmaceutical drug analyses. Chapter 6 presents the FDA approved drugs organized in Disease Focused Posters. Chapter 7.1 and 7.2 present the drug analysis of Sulfur- and Fluorine-Containing Drugs, and Nitrogen-Heterocycle Containing Drugs, respectively.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Vo, Ngoc Tri. "A catalytic enantioselective dearomatization strategy and studies towards the total synthesis of daldinone C". Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611307.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Fischer, Theresa [Verfasser], e Mancheño Olga [Akademischer Betreuer] García. "Enantioselective Nucleophilic Dearomatization of Heteroarenes by Anion-Binding-Catalysis / Theresa Fischer ; Betreuer: Olga García Mancheño". Regensburg : Universitätsbibliothek Regensburg, 2019. http://d-nb.info/1180719484/34.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Rousseaux, Sophie. "Palladium-Catalyzed C(sp2)-C(sp3) Bond Formation". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23058.

Texto completo da fonte

Resumo:

Palladium-catalyzed reactions for carbon-carbon bond formation have had a significant impact on the field of organic chemistry in recent decades. Illustrative is the 2010 Nobel Prize, awarded for “palladium-catalyzed cross couplings in organic synthesis”, and the numerous applications of these transformations in industrial settings. This thesis describes recent developments in C(sp2)-C(sp3) bond formation, focusing on alkane arylation reactions and arylative dearomatization transformations. In the first part, our contributions to the development of intramolecular C(sp3)-H arylation reactions from aryl chlorides are described (Chapter 2). The use of catalytic quantities of pivalic acid was found to be crucial to observe the desired reactivity. The reactions are highly chemoselective for arylation at primary aliphatic C-H bonds. Theoretical calculations revealed that C-H bond cleavage is facilitated by the formation of an agostic interaction between the palladium centre and a geminal C-H bond. In the following section, the development of an alkane arylation reaction adjacent to amides and sulfonamides is presented (Chapter 3). The mechanism of C(sp3)-H bond cleavage in alkane arylation reactions is also addressed through an in-depth experimental and theoretical mechanistic study. The isolation and characterization of an intermediate in the catalytic cycle, the evaluation of the roles of both carbonate and pivalate bases in reaction mechanism as well as kinetic studies are reported. Our serendipitous discovery of an arylation reaction at cyclopropane methylene C-H bonds is discussed in Chapter 4. Reaction conditions for the conversion of cyclopropylanilines to quinolines/tetrahydroquinolines via one-pot palladium(0)-catalyzed C(sp3)-H arylation with subsequent oxidation/reduction are described. Initial studies are also presented, which suggest that this transformation is mechanistically unique from other Pd catalyzed cyclopropane ring-opening reactions. Preliminary investigations towards the development of an asymmetric alkane arylation reaction are highlighted in Chapter 5. Both chiral carboxylic acid additives and phosphine ligands have been examined in this context. While high yields and enantiomeric excesses were never observed, encouraging results have been obtained and are supported by recent reports from other research groups. Finally, in part two, the use of Pd(0)-catalysis for the intramolecular arylative dearomatization of phenols is presented (Chapter 7). These reactions generate spirocyclohexadienones bearing all-carbon quaternary centres in good to excellent yields. The nature of the base, although not well understood, appears to be crucial for this transformation. Preliminary results in the development of an enantioselective variant of this transformation demonstrate the influence of catalyst activation on levels of enantiomeric excess.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Guddehalli, Parameswarappa Sharavathi. "Bifunctional cyclooctynes in copper-free click chemistry for applications in radionuclide chemistry nd 4-Alkylpyridine derivatives in intramolecular dearomatization and heterocycle synthesis". Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/2710.

Texto completo da fonte

Resumo:

Part A. Bifunctional cyclooctynes in copper-free click chemistry for applications in radionuclide chemistry: A new monofluorinated cyclooctyne (MFCO) with a reasonable kinetic profile was synthesized in three steps. We have demonstrated that MFCO can be used as a lynchpin to conjugate biomolecules to radionuclide chelators using copper-free 1,3-dipolar cycloaddition reactions with azides. Many bifunctional biomolecule-chelators were synthesized, and then radiolabelled with very high radiochemical purity and specific activity. MFCO-amine analogues were also synthesized and used in construction of chelator-biomolecule conjugates (particularly, NDP-α-MSH analogues) for applications in radioimaging. Bis-MFCO based bivalent ligands with various linker lengths were also synthesized as precursors to multivalent ligands for use in cancer diagnosis and therapy. Part B. 4-Alkylpyridine derivatives in intramolecular dearomatization and heterocycle synthesis: 4-Alkylpyridine derivatives substituted with different carbon nucleophiles were synthesized and subjected to intramolecular spirocyclization under various conditions to afford synthetically useful diazaspiro[4.5]decanes as well as diazaspiro[5.5]undecanes in good yields. The same 4-alkyl substrates were used to synthesize anhydrobase intermediates which, then participated in aldol-like condensation in the presence of Lewis acid to yield highly conjugated dihydropyridines. Acid hydrolysis produced substituted pyridines tethered with functionalized butyro- and valero lactams. The synthesis of related azaspiro[4.5]decanes and azaspiro[5.5]undecanes from reaction of hypervalent iodine reagents with 4-methoxy-substituted benzyl and phenethyl substrates linked to β-keto amide nucleophiles was also briefly investigated.

Estilos ABNT, Harvard, Vancouver, APA, etc.

El, assal Mourad. "Désaromatisation oxygénante asymétrique de phénols à l'aide d'iodanes pour la synthèse totale de substances naturelles". Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0348/document.

Texto completo da fonte

Resumo:

La réaction de désaromatisation oxygénante de phénols est une transformation très utile en tant qu’étape clé dans la synthèse de substances naturelles complexes. Elle permet de préparer des intermédiaires de type cyclohexa-2,4-diénones à partir de phénols ortho-substitués, notamment en utilisant des réactifs iodés hypervalents (i.e., iodanes) qui constituent une alternative moderne aux réactifs à base de métaux lourds toxiques (e.g., Pb, Tl, Hg). Notre équipe s’intéresse plus particulièrement à la désaromatisation hydroxylante de 2-alkylphénols (réaction HPD) par des iodanes, transformation qui engendre la création d’un centre carboné quaternaire stéréogène. Le contrôle de la configuration de ce centre chiral par l’utilisation d’un substrat ou d’un réactif approprié est un de nos objectifs. Des iodanes chiraux récemment développés au laboratoire ont permis d’atteindre des excès énantiomériques de plus de 90% dans des réactions HPD modèles. Nous avons exploité avec succès ces iodanes chiraux pour réaliser les premières synthèses totales de la (–)-bacchopétiolone et de la (+)-mayténone, ainsi que pour élaborer la tête polaire de type ortho-quinol époxydé de la (+)-scyphostatine
The oxygenative phenol dearomatization reaction is a very useful transformation, as a key step in the synthesis of complex natural substances. It gives access to cyclohexa-2,4-dienones from ortho-substituted phenols, through the use of hypervalent iodine reagents (i.e., iodanes), which constitutes a modern alternative to toxic heavy-metal-based reagents (e.g., Pb, Tl, Hg). Our team is interested in the hydroxylative dearomatization of 2-alkylphenols (HPD reaction) by iodanes, a transformation that results in the formation of one quaternary stereogenic center. Control of the absolute configuration of this chiral center through the use of an appropriate substrate or reagent is amongst our goals. Chiral iodanes recently developed in the laboratory allowed us to reach enantiomeric excesses above 90 % in model HPD reactions. Successful application of these chiral iodanes led us to achieve the first total syntheses of (–)-bacchopetiolone and (+)-maytenone, as well as that of the epoxy ortho- quinol polar head of (+)-scyphostatine

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Livros sobre o assunto "Dearomatization"

You, Shu-Li, ed. Asymmetric Dearomatization Reactions. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

You, Shu-Li. Asymmetric Dearomatization Reactions. Wiley & Sons, Limited, John, 2016.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

You, Shu-Li. Asymmetric Dearomatization Reactions. Wiley & Sons, Incorporated, John, 2016.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

You, Shu-Li. Asymmetric Dearomatization Reactions. Wiley & Sons, Incorporated, John, 2016.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

You, Shu-Li. Asymmetric Dearomatization Reactions. Wiley & Sons, Incorporated, John, 2016.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

You, Shu-Li. Asymmetric Dearomatization Reactions. Wiley & Sons, Limited, John, 2016.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Capítulos de livros sobre o assunto "Dearomatization"

Pigge, F. Christopher. "Dearomatization Reactions". In Arene Chemistry, 399–423. Hoboken, NJ: John Wiley & Sons, Inc, 2015. http://dx.doi.org/10.1002/9781118754887.ch15.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Yoshida, Hiroto. "Dearomatization-Aromatization Sequence". In Transition-Metal-Mediated Aromatic Ring Construction, 773–96. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118629871.ch28.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Zhang, Wei, e Shu-Li You. "Introduction". In Asymmetric Dearomatization Reactions, 1–8. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch1.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Bedford, Robin B. "Dearomatization via Transition-Metal-Catalyzed Cross-Coupling Reactions". In Asymmetric Dearomatization Reactions, 229–46. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch10.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Tsukano, Chihiro, e Yoshiji Takemoto. "Dearomatization Reactions of Electron-Deficient Aromatic Rings". In Asymmetric Dearomatization Reactions, 247–77. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch11.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Lewis, Simon E. "Asymmetric Dearomatization Under Enzymatic Conditions". In Asymmetric Dearomatization Reactions, 279–346. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch12.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Xie, Weiqing, e Dawei Ma. "Total Synthesis of Complex Natural Products via Dearomatization". In Asymmetric Dearomatization Reactions, 347–77. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch13.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Zhang, Wei, e Shu-Li You. "Miscellaneous Asymmetric Dearomatization Reactions". In Asymmetric Dearomatization Reactions, 379–89. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch14.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Kündig, E. Peter. "Asymmetric Dearomatization with Chiral Auxiliaries and Reagents". In Asymmetric Dearomatization Reactions, 9–31. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch2.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mingat, Gaëlle, e Magnus Rueping. "Organocatalytic Asymmetric Transfer Hydrogenation of (Hetero)Arenes". In Asymmetric Dearomatization Reactions, 33–68. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527698479.ch3.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Trabalhos de conferências sobre o assunto "Dearomatization"

Shirley, Harry J., e Christopher D. Bray. "A New Method of Spiroketalization via Cascade Oxidative Dearomatization". In 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-bmos2013_20138255339.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Cossío, Fernando, Aitor Lacambra, Ivan Rivilla e Stéphane Quideau. "New Methods For Stereocontrolled Cycloaddition/Dearomatization Reactions Under Catalytic Conditions". In MOL2NET 2016, International Conference on Multidisciplinary Sciences, 2nd edition. Basel, Switzerland: MDPI, 2016. http://dx.doi.org/10.3390/mol2net-02-h006.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

"Deep eutectic solvents as environment-friendly solvents for separation processes in the oil and gas industry". In Sustainable Processes and Clean Energy Transition. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902516-36.

Texto completo da fonte

Resumo:

Abstract. Oil and gas are still the primary energy source in the world, despite the advancements in renewable energy. Many researchers showed chemical enhanced oil recovery, particularly surfactant is the most efficient method in many reservoirs. But most of these projects were not only commercially successful (due to high cost), but also involve environmental issues. Recently, Deep Eutectic Solvents (DESs) were discovered as a cheaper and greener alternative to conventional surfactants. DESs are cost-effective, easy to prepare, non-toxic, recyclable, biodegradable and environmental-friendly. Due to these advantages, DESs have found application in different fields including the oil and gas industry. The main applications of DESs in the oil and gas industry are separation processes such as dearomatization, desulfurization, purification of biodiesel and CO2 capture. In this paper, the performance of DESs in these processes was reviewed as a new environmentally friendly method. The study introduces a way forward for current challenges with environmental sustainability.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Oferecemos descontos em todos os planos premium para autores cujas obras estão incluídas em seleções literárias temáticas. Contate-nos para obter um código promocional único!