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Artykuły w czasopismach na temat "Borylation reaction"
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Chattopadhyay, Buddhadeb, Mirja Md Mahamudul Hassan, Md Emdadul Hoque, Sayan Dey, Saikat Guria i Brindaban Roy. "Iridium-Catalyzed Site-Selective Borylation of 8-Arylquinolines". Synthesis 53, nr 18 (11.05.2021): 3333–42. http://dx.doi.org/10.1055/a-1506-3884.
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AbstractWe report a convenient method for the highly site-selective borylation of 8-arylquinoline. The reaction proceeds smoothly in the presence of a catalytic amount of [Ir(OMe)(cod)]2 and 2-phenylpyridine derived ligand using bis(pinacolato)diborane as the borylating agent. The reactions occur with high selectivity with many functional groups, providing a series of borylated 8-aryl quinolines with good to excellent yield and excellent selectivity. The borylated compounds formed in this method can be transformed into various important synthons by using known transformations.
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Iwamoto, Hiroaki, Koji Kubota, Eiji Yamamoto i Hajime Ito. "Copper(i)-catalyzed carbon–halogen bond-selective boryl substitution of alkyl halides bearing terminal alkene moieties". Chemical Communications 51, nr 47 (2015): 9655–58. http://dx.doi.org/10.1039/c5cc02760h.
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The carbon–halogen bond-selective borylation of alkyl halides bearing terminal CC double bonds has been achieved using a copper(i) catalyst. This reaction represents a useful complementary approach to conventional procedures for the borylative cyclization reported in our previous work.
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Xie, Jian-bo, Jian Luo, Timothy R. Winn, David B. Cordes i Guigen Li. "Group-assisted purification (GAP) chemistry for the synthesis of Velcade via asymmetric borylation of N-phosphinylimines". Beilstein Journal of Organic Chemistry 10 (31.03.2014): 746–51. http://dx.doi.org/10.3762/bjoc.10.69.
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A new approach to the anticancer drug Velcade was developed by performing asymmetric borylation of an imine anchored with a chiral N-phosphinyl auxiliary. Throughout the 7-step synthesis, especially in the imine’s synthesis and in the asymmetric borylation reactions, operations and work-up were conducted in simple and easy ways without any column chromatographic purification, which defines the GAP (group-assisted purification) chemistry concept. It was found that the optically pure isomer (dr > 99:1) can be readily obtained by washing the crude mixture of the asymmetric borylation reaction with hexane; the chiral N-phosphinyl auxiliary can be easily recovered after deprotection is finished. Several other N-phosphinylimines were also investigated for the asymmetric borylation reaction. The absolute configuration of the borylation product was confirmed by single crystal X-ray diffraction analysis.
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Leon, Noel J., Hsien-Cheng Yu, Thomas J. Mazzacano i Neal P. Mankad. "Pursuit of C–H Borylation Reactions with Non-Precious Heterobimetallic Catalysts: Hypothesis-Driven Variations on a Design Theme". Synlett 31, nr 02 (27.11.2019): 125–32. http://dx.doi.org/10.1055/s-0039-1691504.
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This article presents a retrospective account of our group’s heterobinuclear (NHC)Cu-[MCO] catalyst design concept (NHC = N-heterocyclic carbene, [MCO] = metal carbonyl anion), the discovery of its application towards UV-light-induced dehydrogenative borylation of unactivated arenes, and the subsequent pursuit of thermal reaction conditions through structural modifications of the catalysts. The account highlights advantages of using a hypothesis-driven catalyst design approach that, while often fruitless with regard to the target transformation in this case, nonetheless vastly expanded the set of heterobinuclear catalysts available for other applications. In other words, curiosity-driven research conducted in a rational manner often provides valuable products with unanticipated applications, even if the primary objective is viewed to have failed.1 Introduction to Heterobinuclear Catalysts for C–H Borylation2 Pursuit of Thermal Borylation Conditions3 Catalysts beyond Copper Carbenes4 Conclusions
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Britton, Luke, Jamie H. Docherty, Andrew P. Dominey i Stephen P. Thomas. "Iron-Catalysed C(sp2)-H Borylation Enabled by Carboxylate Activation". Molecules 25, nr 4 (18.02.2020): 905. http://dx.doi.org/10.3390/molecules25040905.
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Arene C(sp2)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp2)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.
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Ji, Hong, Li-Yang Wu, Jiang-Hong Cai, Guo-Rong Li, Na-Na Gan i Zhao-Hua Wang. "Room-temperature borylation and one-pot two-step borylation/Suzuki–Miyaura cross-coupling reaction of aryl chlorides". RSC Advances 8, nr 25 (2018): 13643–48. http://dx.doi.org/10.1039/c8ra01381k.
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Pinet, Sandra, Mathieu Pucheault, Virginie Liautard i Mégane Debiais. "Radical Metal-Free Borylation of Aryl Iodides". Synthesis 49, nr 21 (29.05.2017): 4759–68. http://dx.doi.org/10.1055/s-0036-1588431.
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A simple metal-free borylation of aryl iodides mediated by a fluoride sp2–sp3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.
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Li, Bingru, Huayu Liang, Arumugam Vignesh, Xiaoyu Zhou, Yan Liu i Zhuofeng Ke. "Updated Progress of the Copper-Catalyzed Borylative Functionalization of Unsaturated Molecules". Molecules 28, nr 5 (28.02.2023): 2252. http://dx.doi.org/10.3390/molecules28052252.
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Borylation has become a powerful method to synthesize organoboranes as versatile building blocks in organic synthesis, medicinal chemistry, and materials science. Copper-promoted borylation reactions are extremely attractive due to the low cost and non-toxicity of the copper catalyst, mild reaction conditions, good functional group tolerance, and convenience in chiral induction. In this review, we mainly updated recent advances (from 2020 to 2022) in the synthetic transformations in C=C/C≡C multiple bonds, and C=E multiple bonds mediated by copper boryl systems.
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Geier, Stephen J., i Stephen A. Westcott. "Dehydrogenative borylation: the dark horse in metal-catalyzed hydroborations and diborations?" Reviews in Inorganic Chemistry 35, nr 2 (1.06.2015): 69–79. http://dx.doi.org/10.1515/revic-2014-0008.
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AbstractMetal-catalyzed hydroborations and diborations frequently give “unwanted” side products arising from a competing dehydrogenative borylation reaction. While catalyst development initially focused on avoiding this “deleterious” pathway, fine tuning of a catalyst system could provide an efficient method to generate unsaturated alkenylboronate esters, synthetically valuable synthons for the Suzuki-Miyaura cross-coupling reaction. The aim of this review is to highlight the history and development of the dehydrogenative borylation reaction in the metal-catalyzed synthesis of alkenylboronate esters.
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Steven, Alan. "Micelle-Mediated Chemistry in Water for the Synthesis of Drug Candidates". Synthesis 51, nr 13 (21.05.2019): 2632–47. http://dx.doi.org/10.1055/s-0037-1610714.
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Micellar reaction conditions, in a predominantly aqueous medium, have been developed for transformations commonly used by synthetic chemists working in the pharmaceutical industry to discover and develop drug candidates. The reactions covered in this review are the Suzuki–Miyaura, Miyaura borylation, Sonogashira coupling, transition-metal-catalysed CAr–N coupling, SNAr, amidation, and nitro reduction. Pharmaceutically relevant examples of these applications will be used to show how micellar conditions can offer advantages in yield, operational ease, amount of waste generated, transition-metal catalyst loading, and safety over the use of organic solvents, irrespective of the setting in which they are used.1 Introduction2 Micelles as Solubilising Agents3 Micelles as Nanoreactors4 Designer Surfactants5 A Critical Evaluation of the Case for Chemistry in Micelles6 Scope of Review7 Suzuki–Miyaura Coupling8 Miyaura Borylation9 Sonogashira Coupling10 Transition-Metal-Catalysed CAr–N Couplings11 SNAr12 Amidation13 Nitro Reduction14 Micellar Sequences15 Summary and Outlook
Rozprawy doktorskie na temat "Borylation reaction"
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Palau, Lluch Gerard. "alpha,beta-difunctionalization of alpha,beta-unsaturated carbonyl compounds through borylation reaction". Doctoral thesis, Universitat Rovira i Virgili, 2015. http://hdl.handle.net/10803/311620.
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Aquesta tesi presenta resultats referits a noves metodologies aplicades cap a la obtenció de productes alfa-funcionalitzats i beta-borilats, que no tenen precedents en la bibliografia, a partir de cetones alfa,beta-insaturatdes. Les funcionalitzacions estudiades han sigut utilitzant fluor, per obtenir alfa-fluoro beta-boryl cetones; halogens, per obtenir alfa-halo beta-boryl cetones (sent els halogens clor i brom); i finalment difuncionalitzar cetones alfa,beta-insaturades per obtenir alfa-aryl beta-boryl cetones, que tal i com es reporta a la tesi, han sigut els intermedis cap a la sintesi de 2-aryl-1,3-diones, que són productes de sintesis molt valorats en la industria per les seves propietats com a pesticides.
En tots tres casos, s'ha aconseguit la obtenció dels productes difuncionalitzats, dels quals cap havia sigut previament presentat a la bibligrafia existent, concluent per tant que aquest ha sigut un treball pioner cap a la sintesi i obtenció d'aquests compostos difuncionalitzats.Esta tesis presenta los resultados pertenecientes a nuevas metodologias aplicadas hacia la obtención de productos alfa-funcionalizados y beta-borilados que no tienen precedente en la bibliografia, a partir de cetonas alfa,beta-insaturadas. Las funcionalizaciones estudiadas han sido utilizando fluor, para obtener alfa-fluoro beta-boryl cetonas; halogenos, para obtener alfa-halo beta-boril cetonas (siendo los halogenos cloro y bromo); y finalmente la difuncionalización de cetonas alfa,beta-insaturadas para obtener alfa-aryl beta-boryl cetonas, que tal y como se presenta en la tesis, han sido los productos intermedios hacia la sintesi de 2-aryl-1,3-dionas, que són productos de sintesis muy valorados en la indústria por sus propiedades como pesticidas. En todos los tres casos, se consiguió la obtención de los productos difuncionalizados, de los cuales ninguno habia sido previamente presentado en la bibliografia existente, concluyendo que éste ha sido un trabajo pionero hacia la sintesi y obtención de estos compuestos difuncionalizados.
This thesis presents the results concerning new methodologies towards the obtantion of alpha-functionalized beta-borylated compounds from alpha,beta-unsaturated carbonyl compounds, with no precedent in the litherature. The functionalizations studied focused on fluorine, to obtain alpha-fluoro beta-boryl ketones; halogens, to obtain alpha-halo beta-boryl ketones (being the halogens chlorine and bromine); and finally, the difunctionalization of alpha,beta-unsaturated ketones to obtain the corresponding alpha-aryl beta-boryl ketones, which as presented in this thesis, they have been the intermadiates towards the synthesis of 2-aryl-1,3-diones. 2-aryl-1,3-diones are highly valued products in industry for their properties as pesticides. In the three cases studied, we obtained the desired difunctionalized products, which any of them has been previously presented in the existing literature, concluding that this has been a pioneering work towards the synthesis and obtantion of such difunctionalized compounds.
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Eliseeva, Maria N. "New Route to a [5,5] Carbon Nanotube End-Cap via Direct Borylation of Corannulene". Thesis, Boston College, 2011. http://hdl.handle.net/2345/2752.
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Thesis advisor: Lawrence T. ScottThe Scott lab is interested in the functionalization of corannulene as a building block for large polycyclic aromatic hydrocarbons and carbon nanotube end-cap precursors. Toward that end, a new approach to the direct five-fold borylation of corannulene with iridium (I) catalysts via C-H activation has been explored. It has been discovered that the addition of catalytic amounts of base to the reaction mixture promotes the formation of symmetrical penta-borylated corannulene in a good yield on a sizable scale. All byproducts can be easily removed with iterative methanol washes. The present work also provides proof of the reversibility of the direct borylation reaction under the conditions used. Furthermore, modified Suzuki-Miyaura conditions have been employed to synthesize pentakis(2,6-dichlorophenyl)corannulene, a precursor for a [5,5] carbon nanotube end-cap. The reported reactions provide good yields and are scalable
Thesis (MS) — Boston College, 2011
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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Sasaki, Ikuo. "Development of Novel Synthetic Methods of Organosilicon Compounds Utilizing Silicon-Containing Reactive Intermediates". Kyoto University, 2020. http://hdl.handle.net/2433/253508.
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Gallanti, M. "STEREOSELECTIVE SYNTHESIS OF A-AMINO ACIDS B-SUBSTITUTED WITH A 4,5-DIHYDROISOXAZOLE NUCLEUS AND OF TERTIARY AND QUATERNARY ALLYLSILANES". Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168366.
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In the section A of the thesis is presented a stereoselective synthesis of b-hydroxy-a -amino acids b-substituted with a 4,5 dihydroisoxazole nucleus through an aldol type reaction between Schollkopf reagent and isoxazolynil aldehydes and ketones. In the section B is presented the preparation of allyl- or crotylsilane in high dr and er via the lithiation-borylation reaction of alkylcarbamates with silaboronates.The synthesis of quaternary allylsilane through a related strategy is also presented.
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Larsson, Johanna M. "Transition metal-catalyzed allylic and vinylic functionalization : Method development and mechanistic investigations". Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-89524.
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The use of small molecule building blocks in, for example, pharmaceutical research and new material development, creates a need for new and improved organic synthesis methods. The use of transition metals as mediators and catalysts opens up new reaction pathways that have made the synthesis of completely new compounds possible as well as greatly improved the synthetic routes to known compounds. Herein, the development of new metal-mediated and catalyzed reactions for construction of vinylic and allylic carbon-carbon and carbon-heteroatom bonds is described. The use of iodonium salts as coupling partners in Pd-catalyzed Heck type reactions with alkenes is shown to improve the current substrate scope. Results from a mechanistic study indicate that the reaction proceeds via high oxidation state palladium intermediates. The use of IIII reagents is also believed to facilitate a PdII/PdIV catalytic cycle in allylic silylation of alkenes using (SiMe3)2, which, to the best of our knowledge, is the first method developed for metal-catalyzed allylic C-H silylation. The same silyl-source, (SiMe3)2, has previously been used in a Pd-catalyzed allylic substitution reaction in which allylic silanes are formed from allylic alcohols. A detailed mechanistic investigation of this reaction is described in which by-products as well as intermediates, including the resting state of the catalyst, are identified using 1H, 11B, 19F and 29Si NMR spectroscopy. Kinetic experiments are performed that give information about the turn-over limiting step and the mechanism of the analogous borylation using B2pin2 is also investigated. Insights from this study further made it possible to improve the stereoselectivity of this reaction. Additionally, a new method for Cu-mediated trifluoromethylation of allylic halides is presented in which linear products are formed exclusively from both linear and branched allylic substrates at room temperature. Identification of allylic fluorides as by-products during the reaction also led to the development of a similar Cu-mediated reaction for the fluorination of allylic halides.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.
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Yu, Zhiyong. "Total Synthesis of (+)-Discodermolide by Catalytic Stereoselective Borylation Reactions". Thesis, Boston College, 2014. http://hdl.handle.net/2345/bc-ir:103737.
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Thesis advisor: James P. Morken(+)-Discodermolide is a marine natural product and is one of the most potent microtubule stabilizers in human cell lines. Because of its unique linear structure and important properties, a number of total syntheses of (+)-discodermolide and its derivatives have been reported. Herein, an efficient, highly convergent, and stereocontrolled total synthesis is presented (Chapter 2). The synthesis relied on the development of three catalytic and stereoselective processes: platinum-catalyzed asymmetric diene diboration, nickel-catalyzed diastereoselective hydroboration of chiral dienes (Chapter 1), and nickel-catalyzed borylative diene-aldehyde coupling (see Chapter 4). Combination of these reactions allows preparation of the target in a short sequence. Moreover, the development of rhodium-catalyzed asymmetric hydroformylation (Chapter 3) makes this approach the first Roche ester free (+)-discodermolide synthesis
Thesis (PhD) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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Xu, Conghui. "Rhodium-mediated Activation and Borylation Reactions of Fluorinated Olefins". Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/22174.
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Die Dissertation beinhaltet Studien zur Reaktivität von Rhodiumkomplexen gegenüber unterschiedlichen ungesättigten fluorierten Olefinen mit einem Fokus auf C–F Aktivierungs- und Borylierungsreaktionen.
Der Rhodium(I)hydridokomplex [Rh(H)(PEt3)3] (1) wurde als Katalysator in den Reaktionen von HFO-1234yf, HFO-1234ze, HFO-1225zc bzw. HFO-1225ye (Z) mit HBpin verwendet. Dabei wurden Produktgemische bestehend aus Borylierungsprodukten erhalten. Die selektive Mono- und Dihydroborierung von 3,3,3-Trifluorpropin konnte durch Verwendung von Komplex 1 als Katalysator erreicht werden.
Trifluorethylen konnte durch die Reaktion mit HBpin und Komplex 1 als Katalysator in ein Produktgemisch überführt werden. Stöchiometrische Reaktion zeigen, dass Komplex 1 sowohl unter C–F-Bindungsaktivierung reagiert als auch die Koordination von Trifluorethylen, unter Bildung des Komplexes trans-[Rh(F)(ƞ2-CF2CFH)(PEt3)2], stattfindet. Im Falle von 1,1,2-Trifluorbuten wurde ebenfalls eine C–F-Bindungsaktivierung durch Komplex 1 beobachtet. Mechanistische Untersuchungen der Reaktion von Komplex 1 und 1,1,2-Trifluorbuten bei unterschiedlichen Temperaturen zeigten Hinweise für Koordination & Insertion des Alkens, sowie anschließende β-H-Eliminierung und oxidative C–F-Bindungsadditions- und reduktive HF-Eliminierungsschritte.
Außerdem konnte durch Verwendung von Komplex 1 oder [Rh(Bpin)(PEt3)3] (3) als Katalysator eine stöchiometrische und katalytische Hydroborierung von Pentafluorstyren mit HBpin erreicht werden. Die Rhodium(I)komplexe 1 und 3 sind in der Lage das Olefin zu koordinieren und die C–F-Bindung zu aktivieren, während die Verwendung der Verbindung [Rh(Me)(PEt3)3] die C–H-Bindungsaktivierung fördert. Bei 333 K findet die Aktivierung des fluorierten Aromaten in der 4-Stellung statt, während bei Raumtemperatur die Aktivierung in der 2-Stellung bevorzugt ist.The dissertation reports on studies on the reactivity of rhodium complexes towards different fluorinated olefins with a focus on C–F activation steps and borylation reactions. The rhodium(I) hydrido complex [Rh(H)(PEt3)3] (1) was employed as catalyst in the reactions of HFO-1234yf, HFO-1234ze, HFO-1225zc and HFO-1225ye with HBpin. A product mixture consisting of borylation products was obtained. Selective mono and dihydroboration reactions of 3,3,3-trifluoropropyne were achieved by employing complex 1 as the catalyst. Similarly, trifluoroethylene was also converted into a mixture of products by the reaction with HBpin with complex 1 as the catalyst. A stoichiometric reaction of complex 1 resulted in the C–F bond activation as well as a coordination of trifluoroethylene to give complex trans-[Rh(F)(ƞ2-CF2CFH)(PEt3)2]. Furthermore, the C–F bond activation was also realized with complex 1 and 1,1,2-trifluorobutene. Mechanistic investigations of the reaction of complex 1 towards 1,1,2-trifluorobutene at variable temperatures indicated the formation of products of coordination, insertion of the olefin and subsequent β-H elimination, C–F oxidative addition as well as HF reductive elimination steps. Furthermore, when utilizing complex 1 or [Rh(Bpin)(PEt3)3] (3) as catalysts, stoichiometric and catalytic hydroboration reactions of pentafluorostyrene occurred with HBpin. The rhodium(I) complexes 1 and 3 were capable of the coordination of the olefin and a C–F bond activation reaction with pentafluorostyrene, while complex [Rh(Me)(PEt3)3] promoted the C–H bond activation. At 333 K, the activation of the fluorinated aromatic ring occurred at the 4-position, while at room temperature, an activation at the 2-position was preferred.
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Audi, Hassib. "Synthèse stéréosélective d'aminoacides boronatés et silylés pour le piégeage de fluorures, à visée imagerie médicale". Thesis, Dijon, 2012. http://www.theses.fr/2012DIJOS094.
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La synthèse stéréosélective d'une nouvelle classe d'amino acides boronatés est réalisée par réaction de Wittig, puis borylation catalysée par un complexe d'iridium. Des amino esters portant un noyau aromatique en position δ de la chaîne latérale, sont tout d'abord préparés par réaction de Wittig d'un sel de phosphonium dérivé d'amino acide avec l'aldéhyde aromatique correspondant, puis estérification et hydrogénation. La borylation de ces amino esters avec le bis(pinacolato)diborane (B2Pin2) en présence d'un complexe d'iridium comme catalyseur, conduit aux dérivés correspondants boronatés avec des rendements atteignant 74% . Enfin, des dérivés iodés ou trifluoroboratés sont facilement obtenus à partir des amino acides boronatés, par réaction avec Nal ou avec KHF2. L'hydrolyse des trifluoroborates d'amino acides en solution tampon a été étudiée par RMN 19F. Dans le cas des amino esters difluorophényle et thiophényle, ces composés montrent une très bonne stabilité à l'hydrolyse. D'un autre côté, la synthèse stéréosélective d'amino acides silylés est également obtenue par réaction de Wittig du sel de phosphonium dérivé d'amino acide avec le 4-di-t-butylsilanobenzaldéhyde. L'amino acide silylé a été utilisé pour la préparation d'un dipeptide avec un rendement de 80%, puis son dérivé fluorosilane sans racémisation, par réaction avec KF. Le dipeptide fluorosilylé obtenu montre une excellente stabilité à l'hydrolyse après 10 jours. Finalement, la méthode de synthèse mise au point, se révèle très efficace pour la préparation d'amino acides boronatés et silylés, et pour leur application au marquage par l'iode ou les fluoruresThe stereoselective synthesis of new boronato amino acid derivatives, using Wittig and C-H iridium-catalyzed borylation as key step reactions, is described. Firstly, the synthesis of amino ester precursors bearing an aromatic moiety in -position of the lateral chain, was achieved by Wittig reaction of a phosphonium salt derived from amino acid with the corresponding aromatic aldehyde, then esterification and hydrogenation. The reaction of the amino esters with the bis(pinacolato)diborane reagent (B2Pin2) in presence of an iridium complex as catalyst, leads to the corresponding boronato derivatives in yields up to 74 %. Finally, the iodo- or trifluoroborato derivatives were easily prepared from the boronato amino acid by reaction either with NaI or with KHF2. The hydrolysis of the trifluoroborato amino acid derivatives was studied in buffer solution using 19F NMR monitoring. In the case of the difluorophenyl and thiophenyl amino esters, the corresponding trifluoroborates derivatives show good to excellent stability toward hydrolysis. In addition, the stereoselective synthesis of silano amino acid has been developped by Wittig reaction of the phosphonium salt derived from amino acid with the 4-di-t-butylsilanobenzaldehyde. The silano amino acid was used to prepare a dipeptide with 80% yield, and the corresponding fluorosilane derivative without racemization, by reaction with KF. The hydrolysis of the fluorosilylated dipeptide in aqueous media shows an excellent stability, up to 10 days. Finally, this stereoselective synthesis of hetero substituted amino acids, offers a promising tool for the application of the boronated and silyled derivatives to the fluoride labeling
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Coapes, Richard Benjamin. "Rhodium catalysed borylation reactions via direct and indirect C-H activation". Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4176/.
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This thesis describes both direct and indirect C-H activation borylation processes, catalysed by several Rh-based catalyst precursors. Chapter One presents an overview of the processes investigated, namely diboration, dehydrogenative borylation, and direct C-H activation of hydrocarbon substrates, which give borylated species that are of interest to synthetic chemists. The uses of such borylated species are also highlighted. Chapter Two highlights the synthetic procedure for the synthesis of the catalyst precursor [Rh(acac)(C0E)(_2)], which can be used to prepare bis-phosphine catalyst precursors of the form [Rh(acacXP(_2))]- Although a procedure appears in the literature, it is not well cited. Also, this new procedure replaces [Tl(acac)] with [Na(acac)] and hence avoids the use of thallium salts. Chapter Three investigates the reaction of two vinyl(boronate) esters (VBEs) with Bzcat], and a wide array of catalyst precursors, which yield, among other species, the tris(boronate) esters ArCH(_2)C(Bcat)(_3) and ArCH(Bcat)CH(Bcat)(_3); the former results from the addition of both borons of the B(_2) unit to the same carbon atom, and are of interest due to their wide synthetic versatility. Chapter Four investigates the dehydrogenative borylation of alkenes using both HBpin and B2pin2, and several catalyst precursors. Most significantly, this route allows the synthesis of 1,1-disubstituted vinyl(boronate) esters that cannot be made by alkyne hydroboration. Chapter Five investigates the direct C-H activation of benzylic and aromatic hydrogens using the catalyst precursor [Rh(Cl)(N(_2))(P(^i)Pr(_3))(_2)]. This allows the functionalisation of hydrocarbon substrates, which are ubiquitous. Chapter Six investigates the stability of B-chlorocatecholborane to phosphines with the view to a boron analogue of the Heck reaction. In such a reaction, phosphmes would likely be employed on the catalyst. An understanding of the stability of the boron reagent under typical reaction conditions is needed, therefore, in order to prevent degradation of B-chlorocatecholborane, a process that is known for catecholborane.
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Xu, Conghui [Verfasser]. "Rhodium-mediated Activation and Borylation Reactions of Fluorinated Olefins / Conghui Xu". Berlin : Humboldt-Universität zu Berlin, 2020. http://d-nb.info/1222973480/34.
Pełny tekst źródłaKsiążki na temat "Borylation reaction"
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Ozawa, Yu. Copper(I)-Catalyzed Stereoselective Borylation Reactions. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1098-4.
Pełny tekst źródłaCzęści książek na temat "Borylation reaction"
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Li, Jie Jack. "Miyaura borylation". W Name Reactions, 409–10. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-03979-4_179.
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Li, Jie Jack. "Miyaura borylation". W Name Reactions, 368–69. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01053-8_166.
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Li, Jie Jack. "Miyaura Borylation". W Name Reactions, 362–65. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-50865-4_97.
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Fernández, Elena. "Iridium-Catalyzed Undirected Homogeneous C–H Borylation Reaction". W Topics in Organometallic Chemistry. Berlin, Heidelberg: Springer Berlin Heidelberg, 2020. http://dx.doi.org/10.1007/3418_2020_53.
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Lambert, Tristan H. "Flow Chemistry". W Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0016.
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Although photocatalytic chemistry has been the subject of intense interest recently, the rate of these reactions is often slow due to the limited penetration of light into typical reaction media. Peter H. Seeberger at the Max-Planck Institute for Colloids and Surfaces in Potsdam and the Free University of Berlin showed (Chem. Sci. 2012, 3, 1612) that Ru(bpy)32+-catalyzed reactions such as the reduction of azide 1 to 2 can be achieved in as little as 1 min residence time using continuous flow, as opposed to the 2 h batch reaction time previously reported. The benefits of flow on a number of strategic photocatalytic reactions, including the coupling of 3 and 4 to produce 5, was also demonstrated (Angew. Chem. Int. Ed. 2012, 51, 4144) by Corey R.J. Stephenson at Boston University and Timothy F. Jamison at MIT. In this case, a reaction throughput of 0.914 mmol/h compares favorably with 0.327 mmol/h for the batch reaction. Professor Seeberger has also reported (Angew. Chem. Int. Ed. 2012, 51, 1706) a continuous-flow synthesis of Artemisinin 7, a highly effective antimalarial drug, starting from dihydroartemisinic acid 6. The conversion occurs by a sequence of photochemical oxidation with singlet oxygen, acidic Hock cleavage of the O–O bond, and oxidation with triplet oxygen, a process calculated to be capable of furnishing up to 200 g/day per reactor. A scalable intramolecular [2 + 2] photocycloaddition of 8 to produce 9 was reported (Tetrahedron Lett. 2012, 53, 1363) by Matthias Nettekoven of Hoffmann-La Roche in Basel, Switzerland. Stephen L. Buchwald at MIT developed (Angew. Chem. Int. Ed. 2012, 51, 5355) a flow process for the enantioselective β-arylation of ketones that involved lithiation of aryl bromide 10, borylation, and rhodium-catalyzed conjugate addition to cycloheptenone. For continuous flow production of enantioenriched alcohols such as 14, Miquel A. Pericás of the Institute of Chemical Research of Catalonia developed (Org. Lett. 2012, 14, 1816) the robust polystyrene-supported aminoalcohol 13 for diethylzinc addition to aldehydes. Professor Jamison found (Org. Lett. 2012, 14, 568) that flow chemistry provides a convenient and reliable solution to the reduction of esters to aldehydes with DIBALH (e.g., 15 to 16) that occurs rapidly and without the usual problem of overreduction.
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"11 Nanocatalyzed Borylation Reactions". W Advances in Organoboron Chemistry towards Organic Synthesis, redaktor Fernández. Stuttgart: Georg Thieme Verlag, 2020. http://dx.doi.org/10.1055/sos-sd-230-00188.
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"10 Borylation Reactions in Water". W Advances in Organoboron Chemistry towards Organic Synthesis, redaktor Fernández. Stuttgart: Georg Thieme Verlag, 2020. http://dx.doi.org/10.1055/sos-sd-230-00174.
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Taber, Douglass F. "C–C Bond Construction: The Hou Synthesis of (−)-Brevipolide H". W Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0026.
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Yao Fu and Lei Liu of the University of Science and Technology of China devised (Chem. Eur. J. 2014, 20, 15334) conditions for the coupling of a halide 2 with a tosylate 1 with inversion of absolute configuration, leading to 3. Hegui Gong of Shanghai University coupled (J. Am. Chem. Soc. 2014, 136, 17645) the glucosyl bromide 4 with an anhydride 5 to give the ketone 6. Luigi Vaccaro of the Università di Perugia showed (Org. Lett. 2014, 16, 5721) that TBAF promoted the opening of the epoxide 7 with the ketene silyl acetal 8, leading to the lactone 9. Valérie Desvergnes and Yannick Landais of the University of Bordeaux assembled (Chem. Eur. J. 2014, 20, 9336) the diketone 12 by using a Stetter catalyst to promote the conjugate addition of the acyl silane 11 to the enone 10. Thomas Werner of the Leibniz-Institute for Catalysis reported (Eur. J. Org. Chem. 2014, 6873) the enantioselective conversion of the prochiral triketone 13 to the bicyclic enone 15 by an intramolecular Wittig reaction, mediated by 14. Elizabeth H. Krenske of the University of Queensland and Christopher J. O’Brien also reported (Angew. Chem. Int. Ed. 2014, 53, 12907) progress (not illustrated) on catalytic Wittig reactions. Michael J. Krische of the University of Texas showed (J. Am. Chem. Soc. 2014, 136, 11902) that Ru-mediated addition of 17 to the aldehyde derived in situ from 16 gave 18 with high Z-selectivity. Vladimir Gevorgyan of the University of Illinois at Chicago constructed (J. Am. Chem. Soc. 2014, 136, 17926) the trisubstituted alkene 20 by the intramolecular Heck cyclization of 19. Kálmán J. Szabó of Stockholm University optimized (Chem. Commun. 2014, 50, 9207) the Pd-catalyzed borylation of the alkene 21 followed by in situ addition to the aldehyde 22 to give 23. Boris A. Trofimov of the Irkutsk Institute of Chemistry Siberian Branch developed (Eur. J. Org. Chem. 2014, 4663) aqueous conditions for the preparation of a propargylic alcohol 26 by the addition of an alkyne 25 to the ketone 24. Huanfeng Jiang of the South China University of Technology prepared (Angew. Chem. Int. Ed. 2014, 53, 14485) the alkyne 28 by the oxidative elimination of the tosylhydrazone 27.
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Nakao, Y. "1.15 Nickel-Catalyzed Nondirected C—H Functionalization". W Base-Metal Catalysis 1. Stuttgart: Georg Thieme Verlag KG, 2023. http://dx.doi.org/10.1055/sos-sd-238-00277.
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AbstractThis chapter summarizes some selected examples of nickel-catalyzed nondirected C—H functionalization reactions. Nickel(0) complexes have been demonstrated to be effective for C—H alkylation and alkenylation reactions of arenes and hetarenes through a ligand-to-ligand hydrogen-transfer mechanism for C—H activation that is unique to nickel-catalyzed approaches. They also effect the C—H borylation of arenes and hetarenes. Some nickel(II) complexes are shown to catalyze cross-coupling-type transformations of hetarenes with organic electrophiles through C—H activation by nickel(II) intermediates.
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"2.6 C—H Functionalization Catalyzed by Low-Valent Cobalt". W Base-Metal Catalysis 2. Stuttgart: Georg Thieme Verlag KG, 2023. http://dx.doi.org/10.1055/sos-sd-239-00042.
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AbstractThis review summarizes representative examples of catalytic C—H functionalization reactions mediated by low-valent cobalt complexes. Catalysts generated by the reduction of cobalt(II) or cobalt(III) precatalysts in the presence of appropriate supporting ligands have been demonstrated to promote a variety of alkylation, alkenylation, and arylation reactions of aromatic C(sp2)—H bonds, often with the assistance of directing groups. Well-defined cobalt(0) and cobalt(–I) complexes have also proved to catalyze some of these reactions. Low-valent cobalt complexes supported by bis(phosphinomethyl)pyridine, terpyridine, and diimine ligands have been identified as viable catalysts for the borylation of C(sp2)—H and C(sp3)—H bonds, where the cobalt catalysts exhibit unique site selectivity compared with well-established iridium catalysts. Other reactions such as 1,4-cobalt migration, hydroacylation, and C—H activation involving cobaltacyclopentene intermediates are also discussed.