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1
Pozza, Giorgio, A. Cattazzo, S. Mammi, and T. Carofiglio. "Investigation of the Reaction Mechanism between Bovine Collagen and a Triazine- Based Coupling Reagent - 253." Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34201.
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The triazine-based coupling reagent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) is a promptly water-soluble white solid commonly used in chemical synthesis, which is proven to
act as effective tanning agent. This research work provides an experimental evidence that the tanning ability of DMTMM is associated to an increase of the cross-linking density in the collagen molecule. As a
result of the coupling reaction, DMTMM is converted into water-soluble by-products that can be removed by washing.
Take-Away:
chrome free tanning, reaction mechanism
2
Robinson, Matthew Peter. "Ortho-substituted arylsilanes in oxidative gold catalysis." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31394.
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Organometallic compounds derived from tin, boron, and zinc, have been used extensively in transition metal-catalysed cross-coupling, and continue to hold status as the go-to reagents to form new carbon-carbon bonds. Recently, organosilicon compounds have emerged as an attractive alternative to these established reagents, benefitting from low toxicity, low cost, and general ease of handling. While the fundamental reactivity of arylsilane reagents (Ar-SiR3) is well known, their role in transition metal-catalysed reactions is generally less well studied. This thesis comprises an investigation into the effect of ortho-substitution of these arylsilane reagents, and specifically, their application in gold-catalysed direct arylation. In Chapter 2, the transmetalation of these reagents to gold(III) is assessed using a combination of in situ reaction monitoring coupled with kinetic simulations. This allowed a scale of reactivity to be constructed for a range of structurally diverse arylsilanes, and uncovered that more sterically hindered arylsilanes actually exhibit accelerated rates of transmetalation. In Chapter 3, the reactivity of ortho-substituted arylsilanes in gold-catalysed arylation is addressed. The majority of arylsilanes tested in the previous chapter were found to be unable to undergo coupling, despite the viability of transmetalation having been demonstrated. Slight modification of the ortho-substituent, to incorporate a tethered ligand, was found to have a dramatic effect on reactivity, and allowed the coupling of a variety of substrates. The nature of the ligand, as well as the substitution of the tether was found to have a significant impact on the rate of coupling. Chapter 4 describes the way in which the reactivity of ortho-substituted arylsilanes might be exploited in a 'Catch and Release' protocol for catalyst recovery. This aims to combine the established benefits of homogeneous and heterogeneous catalysis to offer an alternative to current methods of catalyst recycling in industrial chemistry. A number of different 'Catch and Release' mechanisms were considered, and the validity of the concept was demonstrated in a monophasic system.
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Haraguchi, Ryosuke. "Studies on Preparation of Functionalized Organozinc Reagents via Zinciomethylation." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215552.
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Begouin, Jeanne-Marie. "Activation de composés aromatiques et hétéroaromatiques pour la formation de liaisons C-C et C-N par catalyse au cobalt." Thesis, Paris Est, 2009. http://www.theses.fr/2009PEST0033.
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Les réactions de couplage croisé catalysées par des métaux de transition permettant la formation de liaisons C-C et C-hétéroatome sont à la base de la synthèse d’intermédiaires clefs pour la chimie pharmaceutique, la chimie supramoléculaire et la chimie des matériaux. Cependant, certains catalyseurs métalliques utilisés sont reconnus comme étant assez coûteux ou toxiques. Le développement de catalyseurs alternatifs peu coûteux et écologiques, tels que les catalyseurs à base de cobalt qui ont déjà montré leur efficacité pour la formation de liaisons C-C, fait donc l’objet d’études. Nous avons décidé d’utiliser des organozinciques aromatiques fonctionnalisés, obtenus facilement à l’aide d'une réaction catalysée par CoBr2, dans des réactions de couplage catalysées par CoBr2 avec des chloro-diazines et -triazines aboutissant à la synthèse d’aryldiazines et -triazines. Des organozinciques benzyliques ont également pu être utilisés dans ces réactions permettant la synthèse de benzyltriazines. Nous avons également envisagé l’utilisation d’autres types de substrats. Des réactions de couplage catalysées par CoBr2 entre des organozinciques aromatiques et des méthylthiopyrimidines ou le 2- méthylthiobenzo[b]thiazole ont ainsi été réalisées, conduisant à la synthèse de 2,4- diarylpyrimidines ou de 2-arylbenzo[b]thiazoles. Nous avons également étudié la réactivité des dérivés du benzonitrile dans les couplages directs catalysés par CoBr2 avec des halogénures aromatiques basés sur l’activation de la liaison C-CN pour former des biaryles. Enfin, des réactions de couplage croisé C-N entre des halogénures aromatiques et l’aniline conduisant à la synthèse de diarylamines ont été étudiées<br>Transition metal-catalyzed cross-coupling reactions allowing the formation of C-C or C-Heteroatom bonds underlie the synthesis of key intermediates for pharmaceutical, supramolecular chemistry and material sciences. Thereby, the development of these methodologies is prominent and an increasing number of studies are devoted to these processes. However, some metallic catalysts are known to be rather expensive or toxic. Consequently, the development of alternative sustainable catalysts such as cobalt or ironbased catalysts has been studied over the past few years. Cobalt-catalysts have been little-used although they have shown to be effective for various C-C bond forming reactions. Functionalized arylzinc reagents can be readily obtained from the corresponding arylhalides using a CoBr2-catalyzed reaction. First we envisioned using these arylzinc reagents in CoBr2-catalyzed cross-coupling reactions with chlorodiazines and chlorotriazines leading to aryldiazines and aryltriazines. Benzylzinc reagents had also been used in these reactions and we synthesized various benzyltriazines in this manner. We also studied whether we can use other kind of substrates in these reactions. Thus, we performed CoBr2-catalyzed cross-coupling reactions between arylzinc reagents and methylthiopyrimidines or methylthiobenzo[b]thiazole derivatives leading to 2,4-diarylpyrimidines and 2- arylbenzo[b]thiazole. Then, we studied the reactivity of benzonitrile derivatives in direct cross-coupling reactions with arylhalide based on C-CN bond activation using CoBr2 as catalyst. Finally, we also carried out the study of CoBr2-catalyzed C-N cross-coupling reactions for the synthesis of diarylamines
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Findik, Hamide. "Potassium Permanganate/ Carboxylic Acid/ Organic Solvent: A Powerful Reagent For C-c Bond Formation, Aryl Coupling Reactions And Enone Oxidation Ipso-nitration Of Arylboronic Acids With Silver Nitrite/ Tmscl." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610472/index.pdf.
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The first part of the thesis presents the KMnO4/ carboxylic acid/ organic solvent which is a powerful reagent for C-C bond formation, aryl coupling reactions and enone oxidation. The a¢<br>-acetoxylation of enones and the a-acetoxylation of aromatic ketones were carried out with potassium permanganate and acetic acid, in which acetoxylation products were obtained in 74-96% yields. The same reaction was carried out with carboxylic acids other than acetic acid, which furnished corresponding acyloxy ketones with the same regioselectivity. For the first time, formyloxylation products were synthesized in a 61-85% yield by using formic acid.
The potassium permanganate and acetic acid method was also used for aryl coupling reactions. The reaction of arylboronic acids and aryl hydrazines in benzene with potassium permanganate and acetic acid in turn furnished biaryls in a 85-96% yield.
We showed that potassium permanganate/carboxylic acid/organic solvent behaves as manganese(III) acetate.
In the second part of the thesis, ipso-nitration of arylboronic acids with AgNO2/ TMSCl was performed. Nitration of aromatic compounds is one of the most extensively studied reactions, and nitroaryl moieties play key roles in the physical and chemical properties of many target molecules in organic synthesis. For electrophilic nitration of aromatic compounds, a wide variety of reagents are available to date. Most of them are very strong nitrating agents and often lead to
further nitration and mixture of isomers. Since most nitrating agents are oxidants, oxidation of other functional groups can also occur, giving a mixture of products. Thus, a search for milder and selective nitrating agents is a good research goal. In this work, we aimed to apply AgNO2/ TMSCl system to ipso nitration of arylboronic acids.
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Pearson, Mark. "Organometallic reagents for catalytic cross-coupling." Thesis, University of Oxford, 1992. http://ora.ox.ac.uk/objects/uuid:c5eea9a0-8f0c-46bf-a1ea-28a40b79546d.
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Phosphine complexes of nickel and palladium provide the best catalysts for the homogeneous catalysed carbon-carbon bond forming reaction between an organometallic nucleophile and an organic electrophile. Use of a homochiral ligand on the catalyst can lead to stereoselectivity in the cross-coupling reaction, with high ee's of coupled product being obtained. The processes of selectivity in the transmetalation step of the catalytic cycle have not been elucidated and the initial aim of the project was to study these processes. Initial experiments using organotin derivatives as the organometallic nucleophile highlighted the problems of selectivity and the forcing conditions needed in the attempted transfer of a benzyl group from the tin to the palladium catalyst. The compounds [8- (dimethylamino)-1-naphthyl]methyldiphenyltin (60) and [2-((dimethylamino)methyl) phenyl]methyldiphenyltin (70) were prepared and their reactivity in the palladium catalysed cross-coupling with 2-furoyl chloride, to give 2-benzoylfuran, was investigated. These molecules were found to undergo facilitated transfer of a phenyl group compared to transfer from control molecules. The effect was tested and attributed to the internal nucleophilic attack at the tin atom by the lone pair on the nitrogen atom. The compound [2- ((dimethylamino)methyl)-3-trimethylsilylphenyl]methyldiphenyltin (79) was prepared to test the effects of steric buttressing within the molecule, but was found to be of the same order of magnitude of reactivity as (60) and (70). All three molecules showed a reactivity of at least an order of magnitude greater than control compounds. The effect did not prove applicable to the transfer of a benzyl group or in other coupling reactions. The effect of palladium ligation was tested and the ligand triphenyl arsine found to increase the rate of the coupling reaction. The two facilitating processes were found to work in a co-operative fashion, giving a rate enhancement of ca. one hundredfold over control reactions. The nickel catalysed cross-coupling of α-substituted sp<sup>3</sup> hybridised Grignard reagents with allylic esters was attempted, but proved unsuccessful. Stoichiometric reactions with nickel complexes were also found to be unsatisfactory in yielding coupled products. The synthesis of α-substituted diorganozinc reagents was attempted, but furnished only homocoupled products. The reaction of dibenzylzinc with aldehydes was found to proceed in the absence of catalyst, highlighting the reactivity of a benzylzinc moiety.
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Woods, Tom MacDonald. "Phosphinates as new electrophilic reagents for cross-coupling reactions." Thesis, Durham University, 2008. http://etheses.dur.ac.uk/2130/.
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Activated esters, e.g. triflates, sulfonates, nonaflates and phosphates are excellent electrophiles for a variety of cross-coupling reactions. However, other phosphorus-based esters have received little attention in these protocols. This thesis discusses the synthesis and cross-coupling chemistry of vinyl phosphinates, a new class of electrophilic species. A simple model vinyl phosphinate, N-(tert-butyloxycarbonyl)-4,5,6,7-tetrahydro-1H-azepin-2-yl-diphenylphosphinate, was prepared in excellent yield from commercially available caprolactam. A screening study identified Suzuki cross-coupling conditions under which this phosphinate smoothly coupled with a variety of electron-rich, electron-poor and sterically-hindered boronic acids. The scope and limitations of this chemistry were investigated and a variety of electron-withdrawing nitrogen protecting groups, e.g. Boc, CO(_2)Ph, C0(_2)Bn and Ts could be used without problem. However, electron-donating protecting groups, e.g. Me and Bn proved unsuccessful. Additionally, where seven and eight-membered ring lactam phosphinates coupled efficiently, five and six-membered ring derivatives proved largely unsuccessful. Relative reactivity studies were carried out with N-phenyloxycarbonyl-2- (diphenylphosphinoyloxy)-3,4-dihydro-6-bromoquinolone and indicated that the reactivity of vinyl phosphinates lies between that of aryl chlorides and aryl bromides in the Suzuki reaction. Attempts to improve the efficiency of the cross-coupling of this substrate using DoE and PCA modelling was attempted, but was largely unsuccessful. Studies towards the total synthesis of Lennoxamine via a cross-coupling reaction between a benzazepine-derived vinyl phosphinate and 2,3-dimethoxy-N-(2'-phenylpropan-2-yl)-6-(tributylstannyl) benzamide were commenced. Synthesis of the stannane was achieved in high yield via a directed metallation strategy. Unfortunately, preliminary attempts to cross-couple this stannane with N-(benzyloxycarbonyl)-4,5,6,7- tetrahydro-1 H-azepin-2-yl diphenylphosphinate in a model reaction were unsuccessful. Synthesis of the desired benzazepine phosphinate fragment proved more difficult and although progress has been made, this work remains unfinished. Additionally, treatment of N-([4'-methylphenyl]sulfonyl)-2-oxo-azepane with LDA/TMEDA in the presence of diphenylphosphoryl chloride afforded the sultam 1,2,3,4-tetrahydro-7-methylazepino[1,2-b][1,2]benzothiazole-10,10-dioxide in moderate yield. A range of aryl sulfonamides could be used affording the corresponding sultams in moderate yields.
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Schuster, Christopher Henry. "Synthesis and Utility of Organoboron Reagents for Enantioselective Synthesis." Thesis, Boston College, 2014. http://hdl.handle.net/2345/bc-ir:103558.
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Thesis advisor: James P. Morken<br>Described herein are three distinct projects centered on the formation and use of carbon-boron bonds. In the first, the enantioselective platinum-catalyzed 1,4-diboration of trans-1,3-dienes is advanced in both selectivity and scope through the development of a novel class of electron rich chiral monodentate phosphines. Under the action of the new ligands, highly selective diboration is maintained at reduced loadings of catalyst. Secondly, enantioenriched 1,2-bis(pinacol boronates) are engaged in regioselective Suzuki-Miyaura cross-coupling with aryl and vinyl electrophiles. A tandem diboration cross-coupling sequence is successfully implemented to afford homobenzylic and homoallylic pinacol boronates directly from terminal olefins, which subsequently undergo oxidation, amination or homologation of the remaining carbon-boron bond to arrive at a range of enantioenriched products. Lastly, aryl electrophiles containing tethered allylboronate units undergo efficient intramolecular coupling in the presence of a chiral palladium catalyst to give enantioenriched carbocyclic products<br>Thesis (PhD) — Boston College, 2014<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Jensen, Anne Eeg. "Transition metal-catalyzed cross-coupling reactions of functionalized organometallic reagents." Diss., lmu, 2001. http://nbn-resolving.de/urn:nbn:de:bvb:19-2331.
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Sore, Hannah Fiona. "The synthesis and palladium catalysed cross coupling of organosilicon reagents." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608633.
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Stridfeldt, Elin. "Hypervalent Iodine Reagents in Metal-Free Arylations and Vinylations : Investigation of Suitable Coupling Partners and Synthesis of New Reagents." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-141580.
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This thesis concerns the development of metal-free reactions to obtain carbon-heteroatom and carbon-carbon bonds. This is achieved by transferring carbon ligands from hypervalent iodine reagents to suitable nucleophiles. The bulk of the work presented herein concerns arylation of oxygen and nitrogen nucleophiles, using the well-known diaryliodonium salts as aryl sources. In the first project, O-arylation of the oxime ethyl acetohydroxamate was studied. It was found that electron-poor as well as electron-rich aryl moieties could be transferred successfully to this nucleophile. Furthermore, the protocol could be extended to a sequential one-pot synthesis of benzo[b]furans. This method allowed for a fast synthesis of the natural product stemofuran A and formal syntheses of other natural products. In a successive project, O-arylation of hydroxide and aliphatic alkoxides was investigated. It is known that electron-poor aryl moieties can be transferred to these nucleophiles in moderate to high yields. However, combined with more electron-rich diaryliodonium salts, a large amount of side products were formed. These were suppressed upon addition of aryne traps, suggesting that aryne pathways are competing with the desired ligand coupling. It was also observed that secondary alcohols were oxidized to the corresponding ketones. The mechanism for this oxidation was investigated and aryne pathways could be excluded. Instead we suggest that the carbinol hydrogen gets deprotonated via an internal mechanism, after the alkoxide has coordinated to the iodonium salt. Highly sterically congested alkyl aryl ethers could be obtained in high yields by combining tertiary alcohols with ortho-blocked diaryliodonium salts. Next, N-arylation of secondary acyclic amides was studied using acetanilide as the model substrate. This procedure was suitable for transfer of electron-poor as well as ortho-substituted aryl moieties, but attempts to transfer very electron-rich aryl groups were unsuccessful. On the other hand, the amides displayed a complementary reactivity, allowing phenylation of electron-rich amides. In the final project, a one-pot synthesis of the cyclic iodonium reagent vinylbenziodoxolone is presented. These compounds have not been explored as reagents earlier. Initial screenings showed that the vinyl moiety could be transferred to nitrocyclohexane with opposite regioselectivity compared to the acyclic analogue of the reagent.<br><p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>
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Neouchy, Zeïna. "Couplage croisé d’éthers d’énol méthyliques par activation de liaisons C(sp2)-OCH3 catalysée par le nickel et Synthèse d’amines α-trifluorométhylées acycliques optiquement activespar réarrangement de β-aminoalcools α-trifluorométhylés". Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLET016.
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En chimie organique, le développement de méthodes de synthèse robustes et respectueuses de l’environnement a toujours été un défi. De plus, en chimie médicinale, la mise au point de méthodes de synthèse de synthons fluorés de haute valeur ajoutée sont importantes pour avoir accès à des composés bioactifs. Dans ce manuscrit, nous présentons des méthodes efficaces et faciles à mettre en œuvre pour la formation de liaisons carbone-carbone catalysée par le nickel et la formation de liaisons carbone hétéroatome par un réarrangement de β aminoalcools α-trifluorométhylés.Nous avons montré que le couplage croisé entre un éther d’énol méthylique et un réactif de Grignard pouvait être catalysé par un système simple à base de Ni(OAc)2/(O)PPh3 dans des conditions douces (40°C) via l’insertion du nickel dans la liaison C-OMe. Cette méthode a été appliquée à la synthèse d’un composé antitumoral, le DMU-212.La synthèse d’amines α-trifluorométhylées linéaires énantioenrichies a été réalisée selon une réaction de réarrangement régiosélectif de β-aminoalcools α-trifluorométhylés en se basant sur une stratégie établie dans le laboratoire via un intermédiaire aziridinium. Nous avons montré que les produits obtenus pouvaient être engagés dans des réactions de post-fonctionnalisation<br>In organic chemistry, the development of robust and sustainable synthetic methods has always been a challenge. Moreover, in medicinal chemistry, the development of fluorinated building blocks synthetic methods with high value is important to access bioactive compounds. In this manuscript, we report efficient and easy to carry methods for the formation of carbon-carbon bonds catalyzed by nickel and the formation of carbon-heteroatom bonds by a rearrangement of α-trifluoromethyl-β aminoalcools.We demonstrated that it is possible to perform a cross-coupling reaction of an alkenyl methy ether with a Grignard reagent using a simple catalytic system based on Ni(OAc)2/(O)PPh3 under mild conditions (40°C) via the insertion of nickel into C-OMe bond. This method has been applied to the synthesis of an antitumoral agent, DMU-212.The synthesis of enantioenriched linear α-trifluoromethylamine derivatives is reported consisting in a rearrangement of α-trifluoromethyl-β aminoalcool based on an established strategy in our group via an aziridinium intermediate. We have shown that the synthesized compounds can be involved in post-functionalization reactions
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Schade, Matthias. "Cross-Coupling of Benzylic Zinc Reagents, Preparation and Applications of Alkenyl Zinc Reagents, Preparation of Primary Amides and Synthesis of Functionalized Allenes." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-131522.
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Dunet, Guillaume. "Preparation and Reactions of Allylic Zinc Reagents and Transition Metal-Catalyzed Cross-Coupling Reactions." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-78249.
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Tesevic, Verona. "New fluorous catalysts and reagents with multiple recycling options for coupling and oxidation reactions." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981406777.
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Hopkinson, Matthew Neil. "Transition metal catalysis in the presence of fluorinating reagents." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:4f29607a-7aad-473b-aabc-af320ea2b1e5.
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In this thesis, the effect of fluorinating reagents on a selection of transition metal-mediated organic transformations was investigated. The first four chapters are focused on gold-catalysed nucleophilic addition processes performed in the presence of “F⁺” sources. Chapter 1 provides a general introduction to homogeneous gold catalysis and summarises the aims and objectives of the project. The effect of the electrophilic fluorinating reagent Selectfluor (82) on the gold-catalysed rearrangement of propargyl acetates 85 is discussed in Chapter 2. α-Fluoroenones 92 resulting from fluorodeacetylation of an allenyl acetate intermediate were delivered as the major products of these reactions (Scheme i). [Scheme i Gold-Catalysed Rearrangement-Fluorodeacetylation of Propargyl Acetates 85.] By contrast, performing the gold(I)-catalysed cyclisation of allenoates 102 in the presence of Selectfluor (82) led to products of oxidative coupling. The “F⁺” source in these processes most likely acts as an external oxidant in an Au<sup>I</sup</Au<sup>III</sup> redox cycle. In Chapter 3, the cascade cyclisation-intramolecular arylation of benzyl-substituted substrates is discussed whilst the extension of the methodology towards intermolecular homocoupling and intermolecular alkynylation is presented in Chapter 4 (Scheme ii). [Scheme ii Gold-Catalysed Cyclisation-Oxidative Coupling of tert-Butyl Allenoates 102.] In Chapter 5, the feasibility of palladium-catalysed allylic [<sup>18</sup>F]radiofluorination was investigated using high-specific-activity [<sup>18</sup>F]fluoride. This study led to the development of the first transition metal-mediated C-<sup>18</sup>F bond-forming process of relevance for the preparation of radiotracers for PET imaging (Scheme iii). [Scheme iii Palladium-Catalysed Allylic [18F]Radiofluorination of Allylic Methyl Carbonate 227b.] Chapter 6 gives full experimental procedures and characterisation data for all compounds.
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Manolikakes, Georg. "Transition-Metal Catalyzed Cross-Coupling Reactions of Functionalized Organometallic Reagents, Nickel-Catalyzed Amination of Aryl Chlorides and Preparation and Reactions of Organozinc Reagents." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-139921.
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Miralles, Prat Núria. "Catalytic access to (poly)borylated compounds by coupling unsaturated substrates and diboron or methyldiboron reagents." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/462916.
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Aquesta tesi tracta sobre l'ús d'agents diborans i gem-diborilalcans en catàlisi per tal d'introduir un o més fragments borils a substrats insaturats. Per aquest fi, s'han utilitzat diferents reaccions de borilació en condicions organocatalítiques, activant l’agent borant amb un alcòxid format in situ per la combinació de metanol i base. Aquest és el cas de la substitució arílica de salts de iode hipervalent, on fins i tot en absència de base la reacció procedeix degut a la participació del contraió. La diboració d'alquens és un altre exemple de organocatàlisi però amb la incorporació d’un reactiu diborà no simètric com és el BpinBdan, donant a lloc a productes 1,2-diborats mixtes, essent les dos unitats borils de diferent naturalesa. Finalment, també s’ha treballat la reacció de substitució al•lílica en dos vessants: la organocatalítica , que aplicada en alcohols al•lílics i propargílics utilitzant el B2pin2 com agent diborà, genera compostos al•lilboronats i, forçant les condicions de reacció, també s’han obtingut compostos triborats. En la vessant catalitzada pel coure, la qual potencia la nucleofília del bor, s’ha fet ús tant del reactiu 1,1-diborilmetà com del B2pin2 per addicionar a carbonats vinil cíclics, proporcionant productes homoal•lílics i al•lílics borats, respectivament. S’ha estudiat també la borilació d’halurs arílics impedits estèricament mitjançant catalitzadors de Pd, i s’ha explorat la molècula objecte per vies de caracterització no convencional com l’AFM. En tots els casos, s’han obtingut molècules organoborades de gran interès científic degut a la versatilitat de l’enllaç carboni-bor, com s’ha exemplificat també en aquesta tesi.<br>Esta tesis trata sobre el uso de agentes diboranos y gem-diborilalcanos en catálisis para introducir uno o más fragmentos borilos a sustratos insaturados. Con este fin, se han utilizado diferentes reacciones de borilación en condiciones organocatalíticas, activando el agente diborano con un alcóxido formado in situ por la combinación de metanol y base. Éste es el caso de la sustitución arílica de sales de iodo hipervalente, donde aún en ausencia de base la reacción tiene lugar debido a la participación del contraión. La diboración de alquenos es otro ejemplo de organocatálisis pero con la incorporación de un reactivo diborano no simétrico como es el BpinBdan, dando lugar a productos 1,2-diborados mixtos, siendo las dos unidades boriles de distinta naturaleza. Finalmente, también se ha trabajado la reacción de sustitución alílica en dos formatos: la organocatalítica, que aplicada en alcoholes alílicos y propargílicos utilizando el B2pin2 como agente de boración, genera compuestos alilboronados y forzando las condiciones de reacción, se han obtenido también compuestos triborados. En el otro formato catalizado por cobre, el cual potencia la nucleofília del boro, se ha hecho uso tanto del reactivo 1,1-diborilmetano como del B2pin2 para adicionar a carbonatos vinil cíclicos proporcionando productos homoalílicos y alílicos borados, respectivamente. También se ha estudiado la borilación de haluros arílicos impedidos estericamente mediante catalizadores de Pd, y se ha explorado la molécula objeto por vías de caracterización no convencional como el AFM. En todos los casos, se han obtenido moléculas organoboradas de gran interés científico debido a la versatilidad del enlace carbono-boro, como se ha ejemplificado también en esta tesis.<br>This thesis is about the use of diboron and gem-diborylalkane reagents in catalysis in order to introduce one or more boryl fragments to unsaturated substrates. For that reason, different borylation reactions have been employed in organocatalytic conditions, activating the borane reagent with an alkoxide formed in situ by the combination of methanol and base. This is the case of aryl substitution of hypervalent iodionium salts, in which even in the absence of base the reaction takes place due to the participation of counterion. The diboration of alkenes is another example of organocatalysis but with incorporation of a non-symmetrical diboron reagent such as BpinBdan, providing 1,2-diborated products with two different boryl units. Finally, it has been also explored the allylic substitution reaction in two manners: the organocatalytic, that applied to allylic and propargylic alcohols using B2pin2 as diboron reagent generates allylboronate compounds and, using harsher reaction conditions, it could be also obtained triborated compounds. In the other approach a copper catalyst was used to increase the nucleophilic character of boron atom, and employing both 1,1-diborylmethane and B2pin2 reagents to be added to vinyl cyclic carbonates afforded homoallyl and allyl boronate products, respectively. It has been also studied the borylation of sterically encumbered aryl halides through Pd catalysts, and the object molecule has been analyzed by non-conventional characterization methods, such as AFM. In all cases, it has been obtained organoborated molecules with high scientific interest due to the versatility of carbon-boron bond, as it has also been exemplified in this thesis.
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Yamamoto, Yutaro. "Studies on Palladium-Catalyzed Reactions of Aryl Chlorides with Lewis Acidic Boron or Organosilicon Reagents." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225430.
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Kyne, Robert E. "Strategic Applications of Pinacolato Allylboron Reagents: New Reactions in Enantioselective Allyl-Allyl Cross-Coupling and Allylboration to Form New Carbon-Heteroatom Bonds." Thesis, Boston College, 2012. http://hdl.handle.net/2345/3163.
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Thesis advisor: James P. Morken<br>Detailed within this dissertation are three new reactions involving allylboron reagents. Chapter 1 describes the development of Pd-catalyzed allyl-allyl cross-coupling for the preparation of enantioenriched all-carbon quaternary stereogenic centers. This methodology represents a novel approach to a significant challenge for synthetic chemists. Subsequently, an allyl-allyl cross-coupling is described which generates functionally differentiated 1,5-dienes. Such structures allow for several chemoselective manipulations, which add a significant practical note to this cross-coupling methodology. Chapter 2 details the development of the allylboration of nitrosobenzene with (Z)-crotylboronate derivatives, which results in the formation of branched allylic alcohols. This methodology provides a regioselective complement to standard boron oxidation conditions<br>Thesis (PhD) — Boston College, 2012<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Lim, Diane S. W. "Organosilicon reagents in carbon-carbon bond forming reactions : towards the total synthesis of incednine." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:beb3e9cb-087d-4c96-97f4-da611d08f9f9.
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This thesis investigates a total synthesis of the incednine aglycon by utilising alkenylsilane reagents to assemble the pentaenyl and tetraenyl systems through cross-coupling reactions. The early chapters develop methodology to access both cyclic alkenylsiloxanes and functionalised (E)-alkenylsilanes by the controlled hydrogenation of alkynylsiloxanes and silylolefination of aldehydes, respectively, and culminate in the synthesis of a C6-C13 bis(alkenylsilane)incednine fragment (Scheme 1). The C1-C5 and C14-C23 coupling partners are synthesised in three and ten steps from propargyl alcohol and L-alanine methyl ester through phosphorous-based olefination strategies. In the final chapter we describe our first generation approach to incednine which entails orthogonal cross-couplings to construct the C5-C6 and C13-C14 bonds (Scheme 2).
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Lovinger, Gabriel Jordan. "Enantioselective Multi-Component Reactions: Conjunctive Coupling and Related Processes." Thesis, Boston College, 2019. http://hdl.handle.net/2345/bc-ir:108917.
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Thesis advisor: James P. Morken<br>This dissertation details the discovery, development, and mechanistic exploration of several enantioselective processes involving organoboronic esters. The first chapter will discuss electrophile-induced metallate rearrangement reactions, the fundamental reactivity that underlies much of the subsequently discussed work. The second chapter details the discovery and mechanistic study of the metal-induced metallate rearrangement reaction and the multi-component conjunctive coupling reaction manifold and related reactions it enables. The factors that govern the competition between metal-induced metallate rearrangement versus transmetallation will be explored. The third chapter will discuss efforts to understand and overcome the initial limitations of the conjunctive coupling reaction including halide inhibition of palladium catalysis and the inability to engage other organometallic reagents such as organomagnesium nucleophiles, and how this allowed the development of a more general reaction. The fourth chapter discusses the development of an enantioselective triamine–nickel-catalyzed conjunctive coupling reaction of alkyl electrophiles as well as a related nickel-promoted radical-polar crossover reaction and the mechanistic features leading to one reaction manifold or the other. A related enantioselective diamine–nickel-catalyzed tandem radical addition cross coupling reaction of alkyl iodides, alkenylboron reagents, and alkyl- or arylzinc reagents will also be discussed. The fifth chapter will cover the discovery of a diamine–nickel-catalyzed enantioselective carbozincation reaction of alkenylboron compounds which produces enantioenriched α-boryl alkylzinc reagents. The mechanistic investigations undertaken and application of these species in a variety of stereospecific transformation will be discussed along with the preliminary discovery and optimization of a diphosphine-Pd-catalyzed stereoconvergent Negishi cross-coupling reaction of racemic α-boryl alkylzinc reagents<br>Thesis (PhD) — Boston College, 2019<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Someya, Hidenori. "Studies on Coupling Reactions of Alkyl Halides with Organomagnesium and Organolithium Reagents by Cobalt and Silver Catalysts." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142231.
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Grokenberger, Lucie [Verfasser], and Paul [Akademischer Betreuer] Knochel. "Cobalt-catalyzed cross-couplings and acylation reactions using organozinc reagents / Lucie Grokenberger ; Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1214180361/34.
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Namirembe, Sheila. "Stereoselective Synthesis of Organoboron Reagents and their Application Toward the Synthesis of Amphidinolides C and F:." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108841.
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Thesis advisor: James P. Morken<br>This dissertation details three main projects that focus on stereoselective synthesis of organoboron reagents and their application to total synthesis studies. The first chapter describes the development of an enantioselective palladium-catalyzed conjuntive cross-coupling of bis(alkenyl)borates to access chiral allylboron reagents. These reagents are of high synthetic value that is demonstrated through various applications. The second chapter describes the development of a diastereoselective amine-modified boron-Wittig reaction with ketone electrophiles to access trisubstituted alkenyl boronic esters. The synthetic utility of these trisubstituted alkenyl boronic esters is demonstrated through a novel palladium-catalyzed cross-coupling reaction. The third chapter encompassess studies toward the total synthesis of natural products amphidinolides C and F. It highlights the application of methods developed in the Morken laboratory in the context of challenging total synthesis. It also highlights the potential for newly developed conjunctive cross-coupling and boron-Wittig reactions to solve problems in total synthesis<br>Thesis (PhD) — Boston College, 2020<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Bell, Christan Elizabeth. "Synthesis and Reactivity of New Organoboron Reagents and Development of New Methodologies for the Generation of Novel Drug-Like Scaffolds." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265557.
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This research focused on the synthesis of novel ogranoboron reagents in efforts to perform a variety of synthetic transformations, and additionally, the development of new methodologies to generate drug-like scaffolds. Initially, three novel tripod ligands were synthesized, and two were effectively chelated to boron to provide the desired organoborates. Such organoborates were employed in nucleophilic additions where they were found to be ineffective, whereas some activity was observed in Suzuki-Miyaura cross-coupling reactions. An additional project on organoboron compounds was conducted and focused on the development of organoboron frustrated Lewis pairs (FLPs) to facilitate the storage and transfer of hydrogen, nucleophilic addition reactions, and Claisen rearrangements. A new method for synthesizing a pyrrolidine diol unit was accomplished, and this intermediate was utilized to synthesize two FLPs. The reactivity of the FLPs with small molecules was assessed, and the pyrrolidine diol unit was subsequently evaluated for its ability to undergo a multicomponent reaction (MCR) to yield compounds possessing beneficial biological activity. Further research in this area was conducted, and a 5-aminoimidazole scaffold was synthesized employing a new MCR which is more efficient than previously reported methodologies. 5-Aminoimidazoles are frequently found in compounds which possess desirable biological activity, and this novel method was employed to generate a library of eleven 5-aminoimidazoles. Additionally, two post condensation modification reactions were developed. During initial studies, a side product was observed which was identified as a dihydrotriazine, which is another biologically appealing chemotype. Therefore, an enhanced method of synthesizing this product was developed, and a library of eleven dihydrotriazines was produced. In summary, novel organoboron reagents were synthesized, and their activity was evaluated. The pyrrolidine diol utilized to synthesize FLPs was applied towards an MCR. Furthermore, a novel MCR was developed for the synthesis of 5-aminoimidazoles, and an enhanced protocol for the synthesis of dihydrotriazines was found.
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Manolikakes, Georg Verfasser], and Paul [Akademischer Betreuer] [Knochel. "Transition-Metal Catalyzed Cross-Coupling Reactions of Functionalized Organometallic Reagents, Nickel-Catalyzed Amination of Aryl Chlorides and Preparation and Reactions of Organozinc Reagents / Georg Manolikakes. Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2009. http://d-nb.info/1019930152/34.
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Sun, Duo. "Studies towards the synthesis of functionalized aryl fluorides : transition metal catalyzed cross-coupling and fluorination of organoboron reagents." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/43839.
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This thesis covers several synthetic approaches to the generation of highly functionalized aryl fluorides. PtCl₂(SMe₂)₂ and PtCl₂(DMSO)₂ have been applied to catalytic methylation of polyfluoroaryl imines as user-friendly precatalysts. These complexes have demonstrated high selectivity for ortho C-F activation and subsequent functionalization, exhibiting high functional group tolerance while proving more thermal, moisture and air stable than our original catalyst, [PtMe₂(SMe₂)]₂. Nickel-catalyzed Suzuki-Miyaura and Negishi cross-coupling reactions allow rapid functionalized of C-F bonds; we have been able to obtain a variety of highly functionalized aryl-, heteroaryl-, and alkyl-substituted aryl fluoride molecules under mild reaction conditions. Furthermore, we have described a novel fluorination procedure that employs organoboron reagents and electrophilic fluorine sources. This method is rapid, high yielding and can be carried out without inert atmosphere protection and dry solvents.
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Kawamura, Shintaro. "Development of Iron-Catalyzed Cross-Coupling Reactions with Organoaluminum,-magnesium, and -zinc Reagents Directed toward Controlled Organic Synthesis." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174951.
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Groll, Klaus. "Preparation and direct cross-coupling of organoaluminum reagents, studies on SF5-substituted organometallics and regioselective metalations of silylated N-heteroaromatics." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-170529.
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Guo, Wusheng. "Part I. Hypervalent iodine species: reagents and intermediates in oxidative processes Part II. Water-soluble metal nanoparticles (Rh, Au) in catalysis." Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/283353.
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Els reactius de iode hipervalent són oxidants eficients en diverses transformacions oxidatives. Kita havia utilitzat el sistema PIFA/BF3·Et2O per assolir acoblaments oxidatius arè-arè. El nostre grup va extendre aquesta metodologia a l’acoblament oxidatiu directe de quatre components (four-component direct oxidative coupling) en el que estaven implicats binaftalè i arens. Seguint amb el nostre interés en aquest tema, en aquesta tesi hem preparat diversos tris-, tetra- i hexanaftalens arilats, compostos que tenen potencial interès en les àrees dels colorants i dels dispositius òptics orgànics. Dins també del tema dels organoiodans hipervalents, Koser havia emprat una quantitat estequiomètrica de PhI(OH)(OTs) en la formació oxidativa d’enllaços C-O. Atès que el reactiu hipervalent reverteix al correspondent iodoarè, el procés fóu millorat posteriorment per Ochiai mitjançant l’ús de quantitats catalítiques de iodurs d’aril en presència d’un oxidant terminal, de manera que les espècies hipervalents es generaven in situ. En aquesta tesi hem desenvolupat iodurs d’aril immobilitzats pel mètode sol-gel com a catalitzadors reciclables en l’α-tosiloxilació de cetones. Inesperadament, una sílica híbrida derivada de (3-iodopropil)trietoxisilà també va mostrar activitat catalítica. A partir d’aquí, posteriors investigacions van revelar que els iodoalcans poden actuar també com a pre-catalitzadors en aquest procés oxidatiu. En presència d’un oxidant (m-CPBA), els iodoalcans experimenten una degradació oxidativa per donar espècies catalítiques inorgàniques (probablement IO— o IO2-- ). La sobreoxidació de l’espècie inorgànica formada in situ produeix la desactivació del catalitzador i la formació d’una nova fase de l’àcid iódic (HIO3), no descrita fins ara, estructura que s’ha resolt ab initio a partir de dades de difracció de raigs-X de pols.
Per altra banda, les nanopartícules (NPs) metàl.liques són molt útils en catàlisi degut a les particulars propietats derivades de la seva mida i morfología. Es requereix un agent estabilizant (S) per evitar l’aglomeració de les NPs i controlar la reactivitat en la superfície. En aquesta tesi s’ha dissenyat i sintetitzat un nou estabilitzant amb elevat contingut de nitrogen i cadenes de PEG, per preparar NPs d’or(0) i de rodi(0) solubles en aigua. Variant la relació molar S/Rh es controla la mida i la morfologia de les NPs de Rh(0), des de petits clústers a nanoflowers. Un fenòmen similar s’ha observat en les NPs d’Au(0), on la morfologia varia des de petites esferes fins a nanotadpoles i la mida depèn de la quantitat d’estabilitzant. Els nanomaterials s’han caracteritzat completament. Les NPs de Rh en forma de flor han mostrat bona activitat catalítica en la hidrosililació estereoselectiva d’alquins interns i s’han pogut reciclar fàcilment, mentre que les NPs d’Au són catalitzadors eficients i reciclables en la reducció selectiva de nitroarens a les corresponents anilines en aigua a temperatura ambient.<br>Hypervalent iodine reagents are known to act as efficient oxidants in a range of oxidative transformations. Kita and coworkers previously used the PIFA/BF3·Et2O system to achieve the dehydrogenative arene-arene coupling. Our group extended this methodology to a direct oxidative coupling of four molecules involving binaphthalene and arenes. Following the group’s work in this field, we have prepared in this doctoral work new arylated tris-, tetra- and hexa-naphthalene oligomers, which constitute compounds of potential interest in the field of dyes and organic optical devices. As a separate topic on hypervalent organoiodanes, Koser et al. used stoichiometric amounts of PhI(OH)(OTs) in the oxidative formation of C-O bonds. Given that the hypervalent reagent reverts to the parent iodoarene, the process was made catalytic by Ochiai using sub-stoichiometric quantities of the aryl iodides in the presence of a terminal oxidant, with the hypervalent species being generated in situ. In this thesis we have developed recyclable sol-gel immobilized aryl iodides for the catalytic α-tosyloxylation of ketones. Unexpectedly, a hybrid silica derived from (3-iodopropyl)triethoxysilane was also catalytically active. Further investigations revealed that, unexpectedly, even iodoalkanes can act as pre-catalysts for this oxidative process. We found that in the presence of m-CPBA, the iodoalkanes undergo an oxidative breakdown to inorganic catalytic species (likely IO-- or IO2--). Overoxidation of the in situ formed inorganic species resulted in catalyst deactivation via the formation of a hitherto unreported phase of the iodic acid (HIO3), whose structure has been solved ab initio from the powder x-ray diffraction data.
As a second topic, metal nanoparticles are very useful in catalysis due to the particular properties imparted by their size and morphology. A stabilizing agent (S) is usually required to prevent the agglomeration of the NPs, as well as to control the reactivity at the surface. In this thesis, a new PEG-tagged nitrogen-rich stabilizer has been designed and synthesized to prepare water-soluble Au and Rh NPs. We found that by varying the molar ratio S/Rh, we can achieve size and morphology controllable Rh NPs from small atom clusters to nanoflowers. A similar phenomenon was also found for the gold NPs, with morphologies varying from small spheres to nanotadpoles, the sizes of particles depending on the amount of stabilizer. The nanomaterials have been fully characterized. The flower-like Rh NPs proved to be very effective to catalyze the stereoselective hydrosilylation of internal alkynes and they could be easily recycled. The Au NPs were efficient and recyclable catalysts for the selective reduction of various nitroarenes to the corresponding anilines in water at room temperature.
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Benischke, Andreas [Verfasser], and Paul [Akademischer Betreuer] Knochel. "New Iron-, Cobalt- and Nickel-catalyzed cross-coupling reactions : preparation and application of functionalized Aryllanthanum and Arylsamarium reagents / Andreas Benischke ; Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1160876304/34.
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Trenkle, James D. (James Douglas). "Phosphine-promoted cross-coupling reactions of propargylcopper reagents and alkenyl iodides and the total synthesis of (-)-gloeosporone via nickel-catalyzed epoxide-alkyne reductive macrocyclization." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39582.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.<br>Vita.<br>Includes bibliographical references.<br>I. Phosphine-Promoted Cross-Coupling Reactions of Propargylcopper Alkenyl Iodides Reagents and Alkenyl Iodides. An electron-rich phosphine additive is critical and sufficient for propargyl-selective couplings of propargylcopper reagents and alkenyl iodides. This method is complementary to those previously described, in which high allenyl selectivity is observed in analogous coupling reactions. While the basis of the phosphine effect requires further investigation, the information gained in these studies enables the synthesis of complex molecules by way of skipped enyne intermediates. ... II. Total Synthesis of (-)-Gloeosporone via Nickel-Catalyzed Epoxide-Alkyne Reductive Macrocyclization. The total synthesis of macrolide natural product (-)-gloeosporone 1 is described in 10 steps (LLS) and 5.2% overall yield. The key macrocyclization was performed via nickel-catalyzed reductive macrocyclization of an alkyne and a epoxide to give the 14-membered ring in 46% yield (4a ---> 3a; up to 67% yield could be achieved with stoichiometric nickel). This transformation differs from previous strategies in closing the macrocycle of 1 using more traditional approaches such as macrolactonization and ring-closing metathesis. ...<br>(cont.) Additional nickel-catalyzed macrocyclization studies of alkynes and epoxides were undertaken with other alkynylepoxides. With these studies we were able to recognize an important structural pattern (a 6,e-unsaturated ynoate) which might be necessary for efficient cyclization. Using this information, the nickel-catalyzed reductive cyclization of alkynes and epoxides was extended to the formation of 12- and 15-membered rings.<br>by James D. Trenkle.<br>Ph.D.
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Groll, Klaus Verfasser], and Paul [Akademischer Betreuer] [Knochel. "Preparation and direct cross-coupling of organoaluminum reagents, studies on SF5-substituted organometallics and regioselective metalations of silylated N-heteroaromatics / Klaus Groll. Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/105219463X/34.
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Earlywine, Arthur Dale. "The stereochemistry and mechanism of the iron pentacarbonyl-promoted coupling of strained olefins to carbon monoxide : a NMR-facilitated study of the equilibrium constants between and collision complex of a 10,11-diphenyl-1,4:5,8-dimethano-1,4,4a,4b,5,8,8a, 8b-octahydrofluorene-9-one stereoisomer and the lanthanide shift reagent Eu(fod), the electrophilic aromatic thallation of some selected biomolecules, and the synthesis and high resolution NMR study of the two series of 1,4,4a,8a-tetrahydro-endo-1,4-methanonaphthalene-5 ,8-diones and pentacyclo[5.4.0.0,.0." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1985.
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Silva, Márcio Santos da. "Reagentes organometálicos: preparação e reatividade de compostos orgânicos de telúrio." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-06122011-095539/.
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Nesta tese foram desenvolvidas metodologias sintéticas para a preparação de compostos orgânicos de telúrio empregando reagentes organometálicos. Primeiramente, foi estudada a abertura tipo SN2 de lactonas, por organoiltelurolatos de lítio ou magnésio para obtenção dos respectivos ácidos telurocarboxílicos. Os organoiltelurolatos foram preparados a partir da reação do telúrio elementar com o organometálico desejado, evitando a manipulação de diteluretos alquílicos que apresentam odores desagradáveis. As reações de abertura de lactonas são de fácil execução e levam aos produtos em bons rendimentos (60 - 88 %). Além disso, há a possibilidade de transformação funcional dos produtos para alcoóis, a partir de uma redução in situ, ou para acil derivados, por meio da esterificação de Steglich. Os alcoóis obtidos são precursores sintéticos das respectivas espécies dilitiadas. Adicionalmente, foram preparados teluretos de alquil arila funcionalizados a partir da reação entre alquiltelurolatos de lítio com iodetos de arila catalisada por CuI (5 mol %). Também foi explorada a influência de ligantes, o que levou a um aumento do rendimento das reações testadas. Também foi estudada a reatividade de n-butilteluretos vinílicos e arílicos com reagentes organometálicos. Ou seja, foi estudada a reação de troca telúrio/metal com compostos organoilzinco e organoilmanganês. As reações com compostos de organoilzinco apresentaram resultados insatisfatórios, devido à baixa seletividade de transferência de grupos ligados ao zinco. As reações com compostos de manganês apresentaram bons resultados, com seletividade na transferência de ligantes e bons rendimentos dos produtos de captura dos compostos de organoilmanganês com eletrófilos. Foi estudada também a reação de acoplamento cruzado entre compostos de aril Grignard e teluretos de butil-vinila na presença de cloreto de manganês e iodeto de cobre (MnCl2/CuI). A reação ocorreu com elevada estereosseletividade e com rendimentos de moderados a bons.<br>In this PhD thesis synthetic methodologies for the preparation of organic compounds of tellurium employing organometallic reagents were developed. Initially, the SN2 type opening reaction of lactones by means of lithium or magnesium organotellurolates leading to the corresponding carboxylic acids was studied. The metal organotellurolates were prepared by reacting elemental tellurium with organolithium or Grignard reagents, avoiding the manipulation of bad smelling dialkylditellurides. The opening reactions occured easily, leading to the products in good yields (60 - 88 %). The tellurocarboxylic acids were transformed into alcohols by in situ reduction or into acyl derivatives, by a Steglich esterification. The obtained alcohols are precursors of the corresponding dilithium species by reaction with n-butyllithium. Additionally, functionalized arylbutyltellurides were prepared by reacting lithium alkyltellurolates with functionalized aryl iodides in the presence of CuI (5 mol %). The influence of ligands was also explored, leading to improved yields. It was also investigated the reactivity of vinyl butyltellurides with organometallic reagents. The tellurium/metal exchange reaction with organozinc and organomanganese compounds was studied. The reactions with organozinc compounds presented unsatisfactory results, in view of the low selectivity transfer of the groups linked to zinc. The reaction with organomanganese compounds presented better results in view of the fast Te/Mn exchange reaction, selectivity in the ligand transfer and good yields of the organomanganese capture products with electrophiles. It was also studied the cross-coupling reaction between aryl Grignard reagents and vinyl butyl tellurides in the presence of manganese chloride and copper iodide (MnCl2/CuI). The reaction occuried with high stereosselectivity and in moderate to good yields.
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Haas, Diana [Verfasser], and Paul [Akademischer Betreuer] Knochel. "Metalation and functionalization of 5-membered heterocycles and the tropolone scaffold using TMP-bases and cobalt-catalyzed Negishi cross-coupling reactions of (hetero)arylzinc reagents / Diana Haas ; Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1137466839/34.
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Cai, Yingxiao. "Cobalt-catalyzed carbon-carbon bond formation by activation of carbon-halogen or carbon-hydrogen bonds." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX039/document.
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Ce travail de thèse présente le développement de nouvelles réactions de formation de liaisons carbone-carbone. Le premier chapitre décrit la cyanation d’arylzinciques par catalyse au cobalt à partir d’une source non toxique et bénigne, le N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS), et conduit à de bons rendements en benzonitriles correspondants. Dans cette réaction, le cobalt sert de catalyseur non seulement pour la formation des arylzinciques mais aussi pour la formation de liaisons C-CN. Les groupements fonctionnels, cétone et nitrile, sont permis lorsque le complexe de cobalt associé au ligand bipyridine est utilisé. Le deuxième chapitre porte sur l’homocouplage Csp3-Csp3. Un simple halogénure de cobalt permet de catalyser la dimérisation des halogénures d’alkyles et des acétates d’allyles avec de bons à d’excellents rendements. L’ajout d’iodure de sodium permet d’étendre cette réaction aux chlorures et tosylates d’alkyles. Le couplage croisé entre 2 halogénures d’alkyle différents a également été testé mais les conditions doivent être optimisées. Dans le troisième chapitre, le couplage croisé catalysé au cobalt entre des bromures vinyliques et des chlorures benzyliques est présenté. Des halogénures de vinyles et de benzyles porteurs de groupements electrodonneurs ou electroattrateurs peuvent ainsi être couplés efficacement avec rétention de la configuration de la double liaison. Un mécanisme radicalaire semble être impliqué. Enfin, le dernier chapitre décrit l’arylation d’une 2-phenylpyridine avec un arylzincique par catalyse au cobalt par activation d’une liaison C-H et conduit à de premiers résultats encourageants<br>This thesis presents the development of cobalt-catalyzed carbon-carbon bonds formation. The first chapter describes a novel cobalt-catalyzed electrophilic cyanation of arylzinc species, employing benign and non-toxic N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) as the cyano source. In this reaction, cobalt catalyzes both the formation of arylzinc species and the cyanation reaction. Various benzonitriles are synthesized affording good to excellent yields. Using cobalt-bipyridine complexes instead of CoBr2, ketone and nitrile groups can be tolerated. The second chapter reports cobalt-catalyzed Csp3-Csp3 homocoupling reaction. A simple catalytic system could deliver dimers of a number of alkyl halides/pseudohalides and allylic acetates. Sodium iodide is crucial for the homocoupling of unactivated alkyl chlorides and tosylates. This method is extended to alkyl-alkyl cross-coupling; however, the conditions still need to be optimized. The third chapter describes a cobalt-catalyzed vinyl-benzyl cross-coupling. A variety of functionalized vinyl bromides and benzyl chlorides are efficiently coupled under mild conditions in good to excellent yields, with retention of Z/E configuration. A few mechanistic experiments indicate a single electron transfer involved. The last chapter discusses the progress on the cobalt-catalyzed arylation of 2-phenylpyridine with an arylzinc species by C-H activation and promising results are obtained
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Skotnitzki, Juri [Verfasser], and Paul [Akademischer Betreuer] Knochel. "Stereoselective preparation of chiral secondary alkylcopper- and zinc reagents. Subsequent reactions with allylic substrates and palladium-catalyzed cross-couplings with alkenyl and aryl halides / Juri Skotnitzki ; Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1210424460/34.
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Milton, Edward J. "Pd catalysed C-C & C-O bond formation using bis-(dialkyl/diarylphosphino)ferrocene ligands." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/1022.
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A brief introduction explaining phosphine ligand properties, Pd catalysed cross-coupling reactions; the importance of the steps involved in the catalytic cycle (oxidative addition, transmetalation & reductive elimination), mechanistic studies and a comparison of various reactions will give an overview of important cross-coupling reactions and their limitations. The development of a “super-concentrated” (5M) Pd catalysed Kumada type coupling reaction has been developed for coupling a range of aryl bromide and chloride substrates with the Grignard reagents ((p-CF₃-C₆H₄)MgBr)) and PhMgBr in methyl-tetrahydrofuran (Me-THF). Using a range of bidentate ligands such as bis-phosphinoferrocenyl ligands, good conversions were achieved using small amounts of solvent; up to 10 times less than typical procedures in THF. The unsymmetrical Pt complexes of the form [Pt(P-P)Br₂], [Pt(P-P)(Ph)Br] and [Pt(P-P)Ph₂] have been synthesised and characterised. The variations of substituents on the ligand system and the steric bulk have been shown to have a dramatic effect on the rate of transmetalation. The results provide one explanation why 1,1’-bis(di tert-butylphosphino)ferrocene (dtbpf), an excellent ligand for certain Suzuki reactions, is quite poor in reactions where transmetalation is more difficult. Palladium dichloride complexes of the ferrocenylphosphine based ligands 1,1’-bis- (diphenylphosphino)ferrocene (dppf), 1,1’-bis-(diisopropylphosphino)ferrocene (dippf) and 1,1’-bis-(di-tert-butylphosphino)ferrocene (dtbpf) have been shown to be active in the Hiyama cross-coupling of p-bromoacetophenone and vinyltrimethoxysilane (CHCH₂Si(OMe₃)) in the presence of TBAF under thermal heating and microwave conditions. Ligands with the optimum balance for promoting the transmetalation, oxidative addition and reductive elimination steps along the reaction pathway have been identified. Competition experiments are consistent with slow transmetalation being an issue with the Hiyama reaction relative to the Suzuki coupling. A novel protocol has been developed for the synthesis of aryl-alkyl ethers via C-O bond activation under Pd catalysed conditions. Utilising the unsymmetrical 1-bis-(ditertbutyl-1’- bis-diphenylphosphino)ferrocene (dtbdppf) under optimised conditions with silicon based nucleophiles and NaOH or TBAF as an activator, the formation of methyl, ethyl, n-propyl and n-butyl ethers with a range of aryl halides was achieved in good yield.
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Hsu, Wan-Ting, and 徐婉婷. "Palladium-Catalyzed Cross-Coupling Reaction of Aryl Bromides with Organoaluminum Reagent." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/34684450736453849797.
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碩士<br>國立中興大學<br>化學系所<br>97<br>This thesis describes an efficient and practical catalytic system based on palladium(II) acetate and tricyclohexylphosphine for the coupling of aryl bromides with AlArEt2(THF). Effects of ligands, solvents, ratios of ligand to metal, the equivalent of organoaluminum reagent, and reaction time were studied.
Cross couplings of AlPhEt2(THF) catalyzed by 1 mol% Pd(OAc)2 and 2 mol% PCy3 were performed on a variety of bromides at room temperature or temperatures≦60 oC, yielding coupling products in yields up to 97 %.
This thesis also presents a simple and efficient heteroaryl couplings of benzyl bromide with Al(2-furyl)Et2(THF) using palladium(II) acetate and Tri-p-tolylphosphine as catalytic system. Effects of ligands, solvents, ratios of ligand to metal, the equivalent of organoaluminum reagent, and reaction time were studied.
Heteroaryl couplings of Al(2-furyl)Et2(THF) catalyzed by 1 mol% Pd(OAc)2 and 2 mol% P(p-tolyl)3 were performed on benzyl bromide at room temperature, yielding coupling product in conversions up to 99%.
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古博仁. "Palladium catalyzed 3,3-dimethylallene，acid chloride and ditin reagent coupling reaction." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/33910334760968581446.
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ZHAO, YIGANG. "Reduction of Tertiary Benzamides to Benzaldehydes by an in situ-Generated Schwartz Reagent (Cp2Zr(H)Cl); Formal Synthesis of Lysergic Acid 2. Ru-Catalyzed Amide-Directed Aryl C-H, C-N and C-O Bond Functionalizations: C-B Formation, C-C Suzuki Cross Coupling and Hydrodemethoxylation." Thesis, 2010. http://hdl.handle.net/1974/6671.
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Chapter 2 of the thesis describes a highly efficient in situ method for the reduction of amides to aldehydes and aryl O-carbamates to phenols and other transformations involving hydrozirconations. The method, as a three-component-type reaction, involves in situ generation of the Schwartz reagent (Cp2Zr(H)Cl) from Cp2ZrCl2 and the reductant, LiAlH(O-t-Bu)3, and immediate reaction with a substrate. Substrates include aliphatic and aromatic tertiary amides which are reduced to aldehydes, aryl O-carbamates which are reduced to phenols, and alkynes which undergo other transformations via hydrozirconation. Compared to prior methods, this method has advantage in that reagents are inexpensive and stable, reaction times are short, and reaction temperatures are generally conveniently at room temperature. The use of the in situ method described herein instead of the requirement for the synthesis of the commercially available Schwartz reagent is estimated to provide more than 50% reduction in cost.
Chapter 3 of the thesis describes the discovery and development of efficient and regioselective Ru-catalyzed amide-directed C-H, C-N, C-O activation/C-C bond forming reactions, ester-directed C-O activation/C-C bond forming reaction, and amide-directed C-O activation/hydrodemethoxylation reactions under a simple RuH2(CO)(PPh3)3/toluene catalytic system. Of these, the amide-directed C-H activation/cross coupling reaction proceeds well but uniquely on furan 3-amide substrates while the ester-directed C-O activation is effective on the 2-MeO-1-naphthoic acid methyl ester. On the other hand, the amide-directed C-N and C-O activation/coupling reactions are broadly applicable on benzamides and naphthamides. All of these achievements of directed C-H, C-N, C-O activation/coupling reactions complement and may supercede the DoM (directed ortho metalation)-cross coupling strategy, and establish the catalytic base-free DoM-cross coupling process at non-cryogenic temperature as a convenient, economical and green alternative. The new catalytic amide-directed ortho-hydrodemethoxylation reaction has potential value in links to aromatic electrophilic substitution and DoM chemistries. Furthermore, a new borylation reaction via Ru-catalyzed amide-directed C-H activation/C-B bond forming process is also reported herein.<br>Thesis (Ph.D, Chemistry) -- Queen's University, 2010-12-21 11:12:35.564
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"Nickel-catalyzed coupling reaction of dithioacetals with grignard reagents." Chinese University of Hong Kong, 1989. http://library.cuhk.edu.hk/record=b5886202.
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Jeng, Juug-Yuan, and 鄭仲淵. "Palladium-Catalyzed Cross-Coupling Reaction of Organoaluminum Reagents with Propargyl Acetates." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/26041786107182925776.
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碩士<br>國立中興大學<br>化學系所<br>100<br>This thesis describes a simple and economic palladium(II) acetate/phosphine catalytic systems which catalyze cross-coupling reactions of organoaluminum reagents with a variety of substituted propargyl acetates for the synthesis of 1,1,3-trisubstituted or 1,3-disubstituted allenes. Effects of ligands, coordinating or non-coordinating solvents, amounts of organoaluminum reagents, ratios of ligand to metal, and reaction times were studied.
Cross-couplings of a variety of propargyl acetates catalyzed by 1 mol% palladium(II) acetate and 2 mol% tri(o-tolyl)phosphine were performed on trimethylaluminum in tetrahydrofuran at room temperature only in 3 hours to afford the SN2’ substituted allenes in good to excellent yields of up to 94 %.
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Liao, Jung-Wei, and 廖峻緯. "Efficient Nickel-Catalyzed Cross-Coupling Reaction of Organotitanium Reagents with Propargyl Halides." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88405468670526799102.
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碩士<br>國立中興大學<br>化學系所<br>99<br>This thesis describes an efficient nickel(II) chloride /tricyclohexylphosphine catalytic system which catalyzed cross coupling reactions of organotitaninum(IV) reagents with propargyl bromide and chloride. Effects of temperatures, polarities of solvents, ratios of ligand to metal, and reaction times were studied.
Cross couplings of various organotitaninum(IV) reagents catalyzed by 2 mol% nickel(II) chloride and 4 mol% tricyclohexyphosphine with propargyl halides in dichloromethane at room temperature yielded allenes up to 95 %.
Furthermore, the cross coupling reaction of organotitaninum(IV) reagents with the propargylic derivatives using thecatalytic system of dichlorobis(triphenylphosphine)nickel(II) at room temperature in THF afforded allenes or alkyne derivatives in high yield with excellent regioselectivity.
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陸天堯. "Nickel-Catalyzed Cross Coupling of Various Substituted Cyclopropyl Grignard Reagents with Dithioacetals." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/00217869243300206173.
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Huang, Yun-Chi, and 黃韻錡. "Palladium-Catalyzed Cross-Coupling Reaction of Organoaluminum Reagents with Asymmetric Propargylic Esters." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/26484951157860443667.
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碩士<br>國立中興大學<br>化學系所<br>100<br>This thesis reports an effective, convenient, and mild SN2’ substitution reaction system of chiral propargylic esters with aluminum reagents. Effect of metal, ligand, temperatures, coordination or non-coordination solvents, and reaction times were studied.
Three chiral propargyl alcohols of (R)-ArCH(OH)C≡CPh (Ar = C6H5 (1a), 4-MeC6H4 (1b), 4-ClC6H4 (1c)) are prepared from reactions of PhC≡CCHO with ArTi(O-i-Pr)3 catalyzed by 10 mol% titanium catalyst of (R)-H8-BINOL. The propargy alcohols react with acetyl chloride or 2-naphthoyl chloride to give propargyl esters 2b-d in high yields of >90%. 2b-d in enantioselectivities of 97-99% can be obtained from recrystallization of the esters in a 1/10 mixture of ethyl acetate/n-hexane. SN2’ substitution reactions of 2b-d with 0.8 equiv. of AlMe3 catalyzed by 1 mol% Pd(OAc)2 and 2 mol% P(o-tolyl)3 proceed effectively in THF at room temperature over a reaction time of 3 h produced chiral 1-aryl-3-phenyl-1,2-butadiene (4a-c) in good yields of 80-86%. Enantioselectivities of 4a-c are 95-99% ee.
In addition, a system of 2 mol% of Pd(OAc)2 and 4mol% of PPh3 is used for substitution reactions of 2c or 2d with 0.8 equiv. of Al(p-tolyl)3(THF) in THF at an elevated reaction temperature of 60 oC, producing a mixture of 1-Ar-3-Ar’-1-phenyl-1,2-propadiene (4d,4e) and 1-phenyl-3-Ar-3-Ar’-propyne (5d,5e).
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You, Chun-Chi, and 尤春祺. "Nickel-Catalyzed Cross Coupling of Various Substituted Cyclopropyl Grignard Reagents with Dithioacetals." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/38020055588036488584.
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Jensen, Anne Eeg [Verfasser]. "Transition metal catalyzed cross coupling reactions of functionalized organometallic reagents / Anne Eeg Jensen." 2001. http://d-nb.info/965818888/34.
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