Dissertations / Theses on the topic 'Carbon-heteroatom Bond Forming Reactions'

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1

Maluenda, Borderas Irene. "(N-heterocyclic carbene) : metal catalysed carbon-carbon and carbon-heteroatom bond-forming reactions." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/76274/.

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2

Cazin, Catherine Suzanne Julienne. "Catalysis of carbon-carbon and carbon-heteroatom bond-forming reactions : the importance of the palladium source." Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248165.

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3

Hoskins, Travis Justin Christopher. "Carbon-carbon bond forming reactions." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29769.

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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Dr. Christopher Jones; Committee Co-Chair: Dr. Pradeep Agrawal; Committee Member: Dr. Sujit Banerjee; Committee Member: Dr. Tom Fuller. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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4

Casitas, Montero Alícia. "Reactivity of well-defined organometallic copper(III) complexes in carbon-heteroatom bond forming reactions." Doctoral thesis, Universitat de Girona, 2012. http://hdl.handle.net/10803/81985.

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This thesis is focused on the unexplored field of organometallic copper(III) chemistry. Arylcopper(III) complexes have been proposed as key intermediates in Ullmann condensation reactions that consist in the coupling of aryl halides and heteroatom nucleophiles catalyzed by copper. The study of the reactivity of well-defined arylcopper(III) complexes may provide a better understanding of the mechanism of Ullmann condensation reactions, which is still under intense debate. In this doctoral dissertation we study the feasibility of well-defined arylcopper(III) complexes, which are stabilized within macrocyclic ligands, to participate in C-heteroatom bond forming reactions. We develop copper-catalyzed C-N and C-O bond forming reactions, as well halide exchange reactions, including fluorinations, based on Cu(I)/Cu(III) catalytic cycle within model aryl halide substrates. We uncover the fundamental understanding of the two-electron redox steps, oxidative addition and reductive elimination, at copper.
Aquesta tesi es centra en el camp de la química organometàl•lica del coure(III) que roman sense explorar. Els complexos arilcoure(III) s'han proposat com a intermedis clau en les reaccions de condensació Ullmann que consisteixen en l'acoblament d'halurs d'arils i nucleòfils basats en heteroàtoms catalitzades amb coure. L'estudi de la reactivitat de complexos arilcoure(III) ben definits pot proporcionar una millor comprensió del mecanisme de les reaccions de condensació Ullmann, el qual es troba sota un intens debat. En aquesta tesi doctoral s'estudia la viabilitat del complexos arilcoure(III), estabilitzats en lligands macrocíclics, de participar en reaccions de formació d'enllaç carboni-heteroàtom. S'han desenvolupat reaccions de formació d'enllaç C-N i C-O així com reaccions d'intercanvi d'halurs, on s'inclouen fluoracions, catalitzades amb coure i basades en un cicle catalític Cu(I)/Cu(III) utilitzant substrats models d'halur d'aril. S'ha obtingut una comprensió fonamental de les etapes redox a dos electrons, addició oxidant i eliminació reductiva, en coure.
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5

Graßl, Simon [Verfasser], and Paul [Akademischer Betreuer] Knochel. "Elaboration of electrophilic carbon heteroatom bond forming reactions using organozinc reagents / Simon Graßl ; Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1210424398/34.

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6

Bentz, Emilie Louise Marie. "Zinc enolate coupling : carbon-carbon bond forming reactions." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419263.

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7

Gates, Bradley Durward. "Novel thermal and electrochemical carbon-carbon bond-forming reactions /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487847761307998.

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8

Mori-Quiroz, Luis Martin. "Transition metal catalyzed Carbon-nitrogen bond forming reactions." Revista de Química, 2015. http://repositorio.pucp.edu.pe/index/handle/123456789/101381.

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Las reacciones de formación de enlaces carbono-nitrógeno (C–N) son transformaciones fundamentales en la naturaleza y también procesos básicos para la preparación de moléculas y materiales relevantes a las actividades humanas. El desarrollo de reacciones nuevas y eficientes para la formación de enlaces C–N es, por lo tanto, de gran interés en los ámbitos académico e industrial. El progreso logrado en los últimos 20 años se ha enfocado, principalmente, en procesos de formación de enlaces Csp2–N; sin embargo, hay una creciente gama de reacciones catalizadas por metales de transición que permite la introducción de nitrógeno en estructuras alquílicas (formación de enlaces Csp3–N). Este artículo describe una selección de métodos catalíticos modernos para la formación de enlaces C–N.
Carbon-nitrogen (C–N) bond forming reactions are fundamental transformations in nature and also basic processes for the preparation of molecules and materials relevant to human activities. The development of new and efficient reactions for the formation of C–N bonds are therefore of great interest in academic and industrial settings. Progress in the last 20 years has focused mainly in Csp2–N bond forming processes; however, there is growing range of transition metal catalyzed reactions for the introduction of nitrogen in alkyl frameworks (Csp3–N bond formation). This article describes a selection of modern catalytic methods for the formation of C–N bonds.
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9

Tamuang, Suparb. "Mesoporous silica supported catalysts for carbon-carbon bond forming reactions." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3738/.

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The synthesis and characterisation of well-ordered mesoporous silicas, MCM-41, MCM-48, SBA-1, and SBA-2 has been carried out successfully. All of the synthesised materials possess the expected characteristic ordering as confirmed by powder X-ray diffraction. Moreover, surface modification of these mesoporous silicas had also been achieved through the incorporation of alkylamine groups and attachment of an asymmetric organometallic nickel-salen complex. The catalytic activity of the amino and nickel complex-modified mesoporous silica materials was examined for carbon-carbon bond forming reactions; Knoevenagel condensation of benzaldehyde and ethylcyanoacetate, and Kumada-Corriu coupling reaction between an organobromide and Grignard reagent, respectively. All the NH2-mesoporous silica catalysts result in high conversion (>95%) and can easily be reused by washing with water. Furthermore, the catalytic performances of the asymmetric nickel-salen complex bound to mesoporous silicas were found to be greater than 60% which is comparable to the homogenous nickel complex catalyst (62% conversion) but are more easily recycled. The further modification of catalysts to capture the remaining surface silanol groups in the modified-mesoporous silicas has been carried out by using chlorotrimethylsilane to obtain the surface functionalised with trimethyl groups instead of silanols. The methylated catalysts with MCM-41 and MCM-48 as support demonstrate better recyclability, while this was not observed in the cage-like SBA-1 and SBA-2 supports catalyst as the presence of additional trimethylsilyl groups could cause more pore blocking.
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10

Miller, Karen M. (Karen Marie). "Selective, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32482.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.
Vita.
Includes bibliographical references.
Catalytic addition reactions to alkynes are among the most useful and efficient methods for preparing diverse types of substituted olefins. Controlling both regioselectivity and (EIZ)- selectivity in such transformations presents a significant challenge. In reactions that also involve the creation of a new stereocenter, the development of enantioselective processes is highly desirable. Several novel, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes that display excellent regioselectivity and (E/Z)-selectivity are described. These reactions afford synthetically useful allylic and homoallylic alcohols, often with high enantioselectivity. A highly enantioselective method for the nickel-catalyzed reductive coupling of alkynes and aldehydes has been realized using the commercially available (+)- neomenthyldiphenylphosphine as a chiral ligand. Allylic alcohols are afforded with complete (E/Z)-selectivity, generally >95:5 regioselectivity, and in up to 96% ee. In conjuction with ozonolysis, this process is complementary to existing methods of enantioselective [alpha]-hydroxy ketone synthesis. In alkene-directed, nickel-catalyzed reductive couplings of 1,3-enynes with aldehydes and epoxides, the conjugated alkene dramatically enhances reactivity and uniformly directs regioselectivity, independent of the nature of the other alkyne substituent (aryl, alkyl (1°, 2°, 3°)) or the degree of alkene substitution (mono-, di-, tri-, and tetrasubstituted). The highly substituted 1,3-diene products are useful in organic synthesis and, in conjunction with a Rh-catalyzed, siteselective hydrogenation, afford allylic and homoallylic alcohols that previously could not be prepared in high regioselectivity (or at all) with related Ni-catalyzed alkyne coupling reactions. Enantiomerically enriched terminal epoxides can be employed to afford enantiomerically enriched homoallylic alcohols. P-chiral, monodentate ferrocenyl phosphine ligands are efficient promoters of catalytic, asymmetric reductive coupling reactions of 1,3-enynes with aromatic aldehydes and with ketones. The latter represents the first catalytic intermolecular reductive coupling of alkynes and ketones, asymmetric or otherwise, to be reported. Both of these methods afford chiral 1,3-dienes in excellent regioselectivity and modest enantioselectivity. Nickel-catalyzed reductive couplings of 1,6-enynes and aldehydes also display very high (>95 : 5) regioselectivity. Use of a monodentate phosphine as an additive leads to formation of the opposite regioisomer in equal and opposite selectivity (5: >95). These results provide strong evidence for an interaction between the remote alkene and the metal center during the regioselectivity-determining step.
by Karen M. Miller..
Ph.D.
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11

Eno, Meredith Suzanne. "Development of Metal-Catalyzed Asymmetric Carbon-Carbon Bond Forming Reactions." Thesis, Boston College, 2017. http://hdl.handle.net/2345/bc-ir:107422.

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Thesis advisor: James P. Morken
This dissertation describes the development of four metal-catalyzed carbon-carbon bond forming methods. The first project presented is a palladium-catalyzed proparyl-allyl cross-coupling which proceeds via a kinetic resolution to give enantioenriched 1,5-enynes. Next the asymmetric rhodium-catalyzed hydroformylation of 1-alkenes is described. This reaction delivers synthetically useful a-chiral aldehydes in up to 98:2 er and up to 15:1 branched to linear ratio. The development of a unique nickelcatalyzed asymmetric Kumada coupling of cyclic sulfates is presented. Mechanistic studies reveal the reaction proceeds via an SN2 oxidative addition of a chiral nickelcomplex. Finally, a-Substituted allyl bis(boronic) esters, which are derived from 1,2-diboration of 1,3-dienes are shown to undergo allylation and subsequent Suzuki coupling with aldehydes tethered to sp2 electrophiles. The carbocycle products obtained bear three contiguous stereocenters and were used as intermediates in the synthesis of complex molecules
Thesis (PhD) — Boston College, 2017
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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12

Nogi, Keisuke. "Nickel- and Cobalt-Catalyzed Carbon-Carbon Bond-Forming Reactions Employing Carbon Dioxide." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215559.

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13

Frost, Robert Mark. "Carbon-carbon bond forming reactions towards the synthesis of liquid crystal molecules." Thesis, University of Exeter, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436309.

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14

Strieter, Eric R. "Mechanistic studies on metal-catalyzed carbon-nitrogen bond forming reactions." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32427.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.
Vita.
Includes bibliographical references.
Mechanistic studies on copper and palladium-catalyzed C-N bond forming reactions are described. To understand the mechanistic details of these processes, several principles of physical organic chemistry have been employed. Chapter 1. We have investigated the mechanism of the copper-catalyzed N-arylation of amides using aryl iodides, i.e., the Goldberg reaction. The focus of the work has been directed towards amides since this reaction remains the most versatile in the presence of Cu(I)/1,2- cliamine catalyst systems. The results provide insights into the role of 1,2-diamines in modulating the coordination environment around Cu(I). The catalyst is more efficient at high concentrations of 1,2-diamine and high concentrations of amide, as revealed by a nonlinear dependence of the rate on 1,2-diamine concentration. Extended premixing times between the Cu(I) precatalyst and the amide lead to an extensive induction period which can be attenuated by replacing the Cu(I) precatalyst with a Cu(II) precatalyst. Evidence for the reduction of the Cu(II) precatalyst through the oxidation of the amide is also presented. Furthermore, we demonstrate that a 1,2-diamine ligated Cu(I)-amidate may potentially serve as the reactive species that undergoes aryl halide activation. This was established through both its chemical and kinetic competency in the stoichiometric N-arylation process. This behavior has important consequences for new catalyst development since these results show the significance of both the diamine and amide in modulating the overall reactivity of the system. Chapter 2.
(cont.) A systematic mechanistic analysis of Pd(OAc)₂/ monophosphino- biaryl-catalyzed C-N bond forming reactions with aryl chlorides has been performed. The results provide insights into the relationship between the steady-state concentration of active Pd and the size and substitution pattern of the monophosphinobiaryl ligands. These insights into the nature of catalyst activation help highlight the importance of establishing a high concentration of active catalyst. The catalyst derived from the bulkiest ligand in the series, the tri-i-propyl ligand 13, exhibits both accelerated rate and the increased stability required for practical application of this reaction.
by Eric R. Strieter
Ph.D.
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15

Klingensmith, Liane M. (Liane May). "Mechanistic studies on palladium-catalyzed carbon-nitrogen bond forming reactions." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32489.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.
Vita.
Includes bibliographical references (leaves 68-69).
Precatalyst species present in a solution of Pd₂(dba)₃ and Xantphos were identified as Pd(Xantphos)(dba) and Pd(Xantphos)₂ by use of ³¹p NMR and independent syntheses. Pd(Xantphos)₂ was found to form at high ligand concentrations. To determine whether the formation of this species affected reaction rates, reaction calorimetry was used to explore the rate of the palladium-catalyzed coupling of 4-t-butylbromobenzene and morpholine using the ligand Xantphos at varying palladium to ligand ratios. It was found that catalyst activity is dramatically dependent on the concentration of ligand relative to palladium, due to formation of Pd(Xantphos)₂. Two plausible hypotheses for the low activity of Pd(Xantphos)₂ as a precatalyst are (1) a slow rate of dissociation of a ligand from the bis-ligated species, and (2) the high degree of insolubility of Pd(Xantphos)₂. Magnetization transfer experiments were used to probe the rate of dissociation of ligand for the bis-ligated species, and reaction calorimetry experiments were performed using the more soluble t-butylXantphos in comparison to Xantphos to determine whether the insolubility of' Pd(Xantphos)₂ causes it to have relatively low activity. It was found that solubility is not the main cause for the low activity of Pd(Xantphos)₂, and evidence was given to support the hypothesis that low activity results from the slow dissociation of a ligand from the bis-ligated species.
by Liane M. Klingensmith.
S.M.
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16

Fava, Eleonora [Verfasser]. "Visible light mediated photoredox catalysis: reductive carbon-carbon bond forming reactions / Eleonora Fava." München : Verlag Dr. Hut, 2015. http://d-nb.info/1079768645/34.

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17

Ishida, Naoki. "Development of New Carbon-Carbon Bond Forming Reactions Catalyzed by palladium and Nickel." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/57281.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第13848号
工博第2952号
新制||工||1436(附属図書館)
26064
UT51-2008-C764
京都大学大学院工学研究科合成・生物化学専攻
(主査)教授 村上 正浩, 教授 大嶌 幸一郎, 教授 杉野目 道紀
学位規則第4条第1項該当
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18

Seely, Franklin Lee. "Bis(trimethylstannyl)benzopinacolate Promoted Radical Carbon-Carbon Bond Forming Reactions and Related Studies." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1290711413.

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19

Wagaw, Seble-Hiwot Teshome 1971. "Development and application of palladium-catalyzed carbon-nitrogen bond forming reactions." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9522.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1999.
Includes bibliographical references.
Chapter 1. Pd-Catalyzed Cross-Coupling of a-Substituted Optically Active Amines with Aryl Bromides. The palladium-catalyzed coupling reaction of enantiomerically enriched a-substituted amines with aryl bromides is described. The choice of ligand in the palladium-catalyzed coupling reaction is critical to the formation of chiral aniline products without erosion of optical purity. While Pd/P(otolyl) 3 successfully catalyzes the intramolecular aryl amination of optically active asubstituted amines, intermolecular coupling reactions with this catalyst system gives racemized products. In contrast, the corresponding intermolecular coupling reaction of optically active amines with aryl bromides employing Pd/bis(phosphine) catalysts gives products with no decrease in enantiomeric excess. The development of the Pd/Bl NAP-catalyst (BINAP = 2,2'-bis(diphenylphosphino)-1, 1 '-binaphthyl) for the coupling reaction of amines with aryl bromides is described. The use of this catalyst system provides coupled products in significantly improved yields when primary amine substrates are utilized, as well as preventing racemization of chiral substrates. A mechanism for the observed racemization with the Pd/P( o-tolyl)3 catalyst is proposed. A discussion on the difference in reactivity between Pd/P( o-tolyl)3 and Pd/bis(phosphine) catalysts is presented. The utility of this methodology is demonstrated in the synthesis of ( S)-2-methylcarboxylate-N-acetylindoline, which is a key intermediate in the synthesis of a potent ACE inhibitor. Chapter 2. Pd-Catalyzed Amination of Halog enated Heterocycles. Aminopyridines are efficiently synthesized under mild conditions by the cross coupling reaction of 2-, 3-, and 4-bromopyridines, and 2-chloropyridines with primary and secondary amines utilizing Pd/bis(phosphine)-catalysts A variety of aminopyridines were prepared including mono-, di-, tri-, and tetrapyridylamine products. Application of this reaction to the amination of various nitrogen containing halogenated heterocycles is discussed. Chapter 3. A Palladium-Catalyzed Method for the Preparation of lndoles via the Fischer lndole Synthesis. A Pd-catalyzed method for the preparation of N-aryl benzophenone hydrazones is described. The use of 1-2.5 mol % of a Pd/BINAP based catalyst provides N-aryl benzophenone hydrazones in good yields. Using a Pd/9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xantphos) catalyst the desired hydrazones are produced in excellent yields and at 0.1 mol % of catalyst. The N-aryl benzophenone hydrazones are converted to indole products via an in situ hydrolysis/Fischer cyclization protocol. A procedure that extends this methodology to the synthesis of N-alkyl indoles via the intermediacy of N-aryl-N-alkyl benzophenone hydrazones is described. Similarly, the Pd-catalyzed preparation of diaryl benzophenone hydrazones, followed by the hydrolysis/Fischer cyclization protocol affords N-aryl indole products in good yields.
by Seble-Hiwot Teshome Wagaw.
Ph.D.
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20

Kanuru, Vijaykumar. "Understanding surface mediated C-C and C-N bond forming reactions." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608956.

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21

Masuda, Yuusuke. "Development of New C-C Bond Forming Reactions Utilizing Light as Energy Source." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225634.

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22

Hunt, Nicola Anne. "Uses of zirconium, titanium and copper in some asymmetric carbon : carbon bond forming reactions." Thesis, University of Warwick, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369428.

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23

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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24

Biswas, Souvagya. "Asymmetric Catalysis of Carbon-Carbon Bond Forming Reactions: Use of a Sustainable Feedstock Ethylene." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1449830785.

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25

Senecal, Todd D. (Todd Dale). "Carbon-trifluoromethyl bond forming reactions and palladium-catalyzed cyanation of (hetero)aryl halides." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82321.

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Thesis (Ph. D. in Organic Chemistry)--Massachusetts Institute of Technology, Dept. of Chemistry, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references.
Chapter 1 Nucleophilic trifluoromethyl sources were systematically examined in stoichiometric palladium experiments to determine the most efficient class of reagents for transmetallation. In conjunction with reductive elimination studies, this led to the development of the first system for the trifluoromethylation of aryl chlorides. Chapter 2 A method for the oxidative trifluoromethylation of (hetero)aryl boronic acids is reported. Bench top setup and visual reaction monitoring makes this process particularly well suited to medicinal and academic chemists. Fast reaction times allow for the trifluoromethylation of heterocyclic boronic acids that are prone to facile protodeboronation. Chapter 3 A trifluoromethylation of potassium vinyl trifluoroborates via iron catalysis has been developed. Excellent E:Z ratios are observed for styryl trifluoroborates. Initial investigations suggest a mechanistic pathway that diverges from our previous (hetero)aryl trifluoromethylation systems. Chapter 4 A highly efficient system for the palladium-catalyzed cyanation of (hetero)aryl halides is disclosed. By employing palladacycle precatalysts, cyanide binding during catalyst formation is minimized, allowing for low catalyst loadings even with unactivated aryl chlorides. The method utilizes a non-toxic cyanide source and exhibits excellent functional group tolerance, particularly of free N-H groups and typically challenging five membered heterocycles.
by Todd D. Senecal.
Ph.D.in Organic Chemistry
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26

Lau, Chi-yin. "Reductive aldol cyclizations using Stryker's reagent and polystyrene-supported triphenylarsine in carbon-carbon bond forming reactions." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39634450.

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27

Lau, Chi-yin, and 劉志賢. "Reductive aldol cyclizations using Stryker's reagent and polystyrene-supported triphenylarsine in carbon-carbon bond forming reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39634450.

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28

Chen, Jinshui. "Studies on Transition Metal-catalyzed Carbon-Carbon Bond Forming Reactions through Intramolecular Activation of Organosilicon Compounds." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/57272.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第13828号
工博第2932号
新制||工||1433(附属図書館)
26044
UT51-2008-C744
京都大学大学院工学研究科材料化学専攻
(主査)教授 檜山 爲次郎, 教授 大嶌 幸一郎, 教授 松原 誠二郎
学位規則第4条第1項該当
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29

Doda, Kanae. "Development of Asymmetric Carbon-Carbon Bond-Forming Reactions Using Novel Catalysis of Chiral Quaternary Ammonium Fluorides." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147843.

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30

Williams, Amie L. "The development of new carbon-nitrogen bond forming reactions towards the synthesis of mitomycin C /." [Bloomington, Ind.] : Indiana University, 2004. http://wwwlib.umi.com/dissertations/fullcit/3203870.

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Thesis (Ph.D.)--Indiana University, Dept. of Chemistry, 2004.
Title from PDF t.p. (viewed Nov. 10, 2008). Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0900. Adviser: Jeffrey N. Johnston.
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31

Gonda, Elizabeth. "Cyclic Ether Synthesis via Lewis Acid Promoted Carbon-Carbon Bond Forming Cyclization Reactions of Unsaturated and Saturated Symmetric Acetals." W&M ScholarWorks, 1988. https://scholarworks.wm.edu/etd/1539625450.

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32

Ciccolini, Rocco P. "Carbon-nitrogen bond-forming reactions in supercritical and expanded-liquid carbon dioxide media : green synthetic chemistry with multiscale reaction and phase behavior modeling." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43203.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2008.
Includes bibliographical references.
The goal of this work was to develop a detailed understanding of carbon-nitrogen (C-N) bond-forming reactions of amines carried out in supercritical and expanded-liquid carbon dioxide (CO2) media. Key motivations behind this study were the importance of nitrogen-containing compounds in the pharmaceutical and fine chemical industries and a growing commercial interest in utilizing environmentally-friendly syntheses and processing with cost-efficient, green solvents. The thermodynamics and reaction engineering characteristics associated with the synthesis of several model C-N bond-forming reactions were examined both experimentally and theoretically. Operating conditions and engineering correlations were identified that will facilitate process scale-up and potential commercialization of these and other fundamentally-important CO2-based processes. Amine chemistry in CO2-based media was complicated by the facility of nucleophilic amines to react with carbon dioxide to form carbamic acids, which sometimes interfered with desired reaction pathways. Experimental observations and a complimentary ab initio quantum chemical calculation study revealed that carbamic acid formation was suppressed when adding bulky N-substituents to primary amines and when operating at low pressures and/or high temperatures. With a firm understanding of amine-CO2 chemistry, we developed a synthetic protocol that produced classes of pharmacologically-significant nitrogen heterocycles known as tetrahydroisoquinolines and tetrahyrdo-carbolines. Our method involved (1) the in situ carbamation of amines from their reaction with carbon dioxide and a dialkyl carbonate and (2) the Pictet-Spengler cyclization of these carbamates by their reaction with an aldehyde in the presence of acid. The conversion of amines to their carbamate derivatives offered suitable N-protection against carbamic acid formation.
(cont.) For nearly all reactions studied, the Pictet-Spengler step proceeded nearly quantitatively. The efficiency of amine carbamation via the CO2/dimethyl (cont) carbonate (DMC) reaction system was highly sensitive to process operating conditions. Phase behavior, amine conversion, and carbamate yield and selectivity all varied appreciably with temperature, pressure, and amine feed concentration. For example at 130 oC, carbamate selectivity increased from 50 to 75% with increasing pressure up to the mixture critical pressure of the CO2/DMC binary system (P, mixco2/DMC ). Selectivity decreased to 55% for ... mix of the entire reaction system (P,mixsystem). Above Pmixsytem,, selectivity increased to 80%. At 105 bar, decreasing temperature from 150 to 100 oC led to an increase in carbamate selectivity by 25%. Finally, decreasing the amine feed concentration from 4 to 1 M resulted in an increase in carbamate selectivity by 30%. Mixture critical pressures (Pc,mix) and liquid-phase densities, species concentrations, and volume expansion were measured for the CO2/DMC system over a wide range of operating conditions. Importantly, we developed an equation-of-state (EOS) model and several empirical engineering correlations that were used to predict vapor-liquid equilibrium properties in P-T-xi regimes for which data were not available. Deviations from experimental data and empirical correlations were typically less than 9%. Pmix CO2/DMC data were measured for 37 < T < 150 oC and were correlated well by a third-order polynomial. Liquid-phase carbon dioxide concentration ([CO2]I) varied linearly with pressure for 37 to 100 oC. Liquid-phase volume expansion (AV/) measured for the same temperature range increased exponentially with increasing pressure. Maximum-possible values of [C02]1 and AVI decreased with increasing temperature. [CO211 was 2 to 4 times larger than that of pure CO2 when compared at the same Tand P.
(cont.) We also developed and optimized a practical and high atom-economy C02-based synthetic protocol that afforded amides via the amination of ketenes generated in situ from the thermolysis of 1-alkynyl ethers. A variety of amines, 1-alkynyl ethers, and ketenes participated efficiently in the reaction and produced amides in yields comparable to those of conventional solvents. Experimental phase partitioning observations agreed well with EOS-based predictions and aided in the determination of process operating conditions. Amide yield varied in the order secondary > branched-primary > primary amines, which suggested that carbamic acid formation may have diminished reaction efficiency. t-butoxy-substituted 1-alkynyl ethers produced ketenes at rates faster than ethoxy-substituted ethers and allowed for a considerable reduction in operating temperature. Extension of the amide synthesis protocol to an intramolecular variant that afforded lactams resulted in a significant decrease in selectivity when compared to conventional solvents. We suspected that multi-phasic behavior led to this discrepancy and were able to increase selectivity by 25% using CO2/co-solvent mixtures. Finally, an ab initio quantum chemical kinetic model was developed and was capable of qualitatively predicting observed amide formation dynamics. Product selectivity and amine consumption rate predictions, for example, agreed well with experimental data.
by Rocco P. Ciccolini.
Ph.D.
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33

Nicewicz, David Andrew Johnson Jeffrey Scott. "The [1,2]-Brook rearrangement novel carbon-carbon bond forming reactions and application to the total synthesis of zaragozic acid C /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,1275.

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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.
Title from electronic title page (viewed Mar. 27, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
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34

Kennington, Stuart. "The development of new, direct and asymmetric Ni(II) catalysed carbon-carbon bond forming reactions and their application to total synthesis." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670342.

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This thesis focuses on the search for new methodologies for the direct, stereoselective and catalytic formation of carbon-carbon bonds through the formation of chiral nickel(II) enolate species and the application of such methods to the synthesis of natural products. The project starts with the stereocontrol coming from chiral auxiliaries, developed first by Evans and then later by Crimmins and Nagao, following the previous experience and expertise of the research group. These auxiliaries have proved to be a reliable and high yielding option to afford excellent levels of stereocontrol in various reactions. Furthermore, they can be removed after such processes to leave enantiopure synthons. However, they do have their drawbacks, one being the inability of synthesising all of the available stereoisomers from one starting material. To combat this issue, the second part of the thesis is centred around the development of a new methodology based on achiral starting materials (scaffolds) with chiral nickel(II) complexes, which both enable the reaction and control its stereochemical outcome. In the first Chapter, methods previously developed in the group were applied to the synthesis of a fragment of the marine sponge macrolide Peloruside A, which has shown to have anticancer activity, especially against leukaemia. Three key steps involve reactions based on the use of chiral auxiliaries that had been developed in the group: a nickel catalysed reaction with trimethyl orthoformate, a titanium-mediated acetate aldol reaction, and a titanium-mediated addition of an acetate enolate to an acetal. The overall yield of the synthesis of the target fragment C9-C19 was 24% over 14 steps. Chapter 2 presents a new reaction based on the addition of enolates, generated from chiral N-acyl thiazolidinethiones with an achiral nickel(II) complex, to stable carbocationic salts. This alkylation reaction was first thoroughgoingly optimised and later applied to a large range of substrates with wide success. Moreover, it was applied to a highly challenging electrophile successfully which lead to the discovery of a reversible alkylation process. The products were also transformed via the removal of the auxiliary to leave a variety of functional groups. In Chapter 3 the stereocontrol is passed from the starting material to the catalyst in an ambitious advancement of the group’s chemistry. After an extensive study of potential achiral scaffolds to provide the platform for the reactions and chiral diphosphine ligands to provide the enantiocontrol, we observed the best scaffold was the 6-memberd thiazinanethione structure and the best ligand DTBM-SEGPHOS®. We were able to apply this methodology to the reaction of: trimethyl orthoformate (an oxocarbenium precursor), tropylium tetrafluoroborate (a cationic salt), a diaryl methyl ether (a carbenium precursor), and also a more complex diaryl ketal electrophile with high yields and exceptional control over the one stereocentre formed. Furthermore, using a dimethyl acetal we were able to exert some control over the relative configuration of two stereocentres whilst maintaining exceptional enantioselectivity. Calculations and elucidation of the configuration of the new stereocentre formed support our hypothesis for the mechanism for such a process. We also demonstrated the ease with which the scaffold can be removed and were able to synthesise a wide variety of synthons with differing functional groups. Finally, we were able to scale up and apply the methodology to the synthesis of Peperomin D, a five membered lactone containing two stereocentres. Finally, in the last Chapter we present a new methodology for the asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalysed by a chiral nickel (II) complex, which involves the simultaneous silyl protection of the adducts. This new reaction proceeds through an open transition state and leads to the anti-aldol products. We were able to optimise the reaction to achieve a high diastereoselectivity, exceptional enantioselectivity, and excellent yield. Furthermore, we were able to apply the conditions to various aromatic aldehydes and N-acyl thiazinanethiones. Finally, the scope of the reaction was expanded to three different electrophiles, opening new lines of investigation.
La present Tesi Doctoral està adreçada a la cerca de noves metodologies per a la formació directa, estereoselectiva i catalítica d’enllaços carboni–carboni a partir de derivats carboxílics i la seva aplicació a la síntesi de productes naturals. Inicialment, s’avalua el control estereoquímic que proporcionen auxiliars quirals com les oxazoldininones d’Evans o les seves versions sulfurades degudes a Crimmins i Nagao. Tots aquests auxiliars han resultat ser una excel·lent plataforma per a nombrosos processos estereoselectius. No obstant això, tenen las seves limitacions, sobretot la falta de accés a tots els isòmers d’un determinat material de partida. En aquest sentit, la segona part de la Tesi s’ha centrat en el desenvolupament de metodologies paral·leles a partir d’auxiliars aquirals (scaffolds) i carregant el control estereoquímica sobre catalitzadors de níquel(II) quiral. El primer capítol descriu la síntesi del fragment C9-C19 de la pelorusida A amb un rendiment del 24% en catorze etapes. La construcció estereoselectiva dels enllaços C–C estratègics s’ha aconseguit mitjançant sengles metodologies desenvolupades pel grup basades en l’ús d’auxiliars quirals. En el segon capítol presentem una nova reacció d’alquilació d’N-acil tioimides quirals amb sals carbocatiòniques estables catalitzada per complexos de níquel(II). Després d’una exhaustiva optimització, la reacció s’ha aplicat a diferents substrats amb molt bons resultats. Al tercer capítol el control estereoquímic es trasllada al catalitzador. Després d’un estudi molt detallat es va descobrir que els millors resultats en un ampli ventall de processos d’alquilació s’assolien amb N-acil tiazinantiones que incorporen un scaffold aquiral de sis baules en presencia d’un complex quiral de níquel(II). Aquesta metodologia ha estat aplicada a la síntesi de la peperomina D. Finalment, en el quart capítol es desenvolupa una nova reacció aldòlica. Partint dels resultats obtinguts als capítols anteriors s’han trobat unes condicions per a la síntesi d’aldols sililats d’estereoquímica anti amb rendiments elevats i una extraordinària enantioselectivitat. A més s’han obert tres línies de investigació basades en l’ús de diferents electròfils.
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35

Burke, Elizabeth Diane. "Stereoselective carbon-carbon bond forming reactions : improving the stereoselectivity of a catalytic homoaldol reaction and the development of a general method to access the [alpha]-quaternary carbon [beta]-hydroxy carbonyl motif." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85054.

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The following thesis describes two stereoselective carbon-carbon bond forming processes---the aldol reaction and its one-carbon homologue, the homoaldol reaction. The first chapter describes our efforts to increase the stereoselectivity of a catalytic homoaldol reaction. This methodology features a second generation Binol titanium (IV) fluoride catalyst capable of opening a silyloxycyclopropane ring to form discrete homoenolates. These homoenolates react with a variety of aldehydes to form 1,4-hydroxy carbonyl compounds. The catalyst was prepared by a literature method and has improved the stereoselectivity of this reaction compared to the first generation Binol titanium (IV) triflate catalyst. A variety of substituted Binol ligands were studied to determine the effect of steric and electronic modifications on reaction selectivity.
In the second chapter, a general method for the asymmetric synthesis of alpha,alpha-disubstituted-beta-hydroxy carbonyl compounds is described. This methodology relies on the stereoselective formation of acyclic alpha,alpha-disubstituted amide enolates. These enolates were prepared using methodology developed in the Gleason laboratory. Transmetallation of the initially formed lithium enolate was necessary to achieve high relative and absolute product stereocontrol. The E- and Z-enolate isomers were investigated. The Z-enolate reacted with high stereocontrol, whereas the E-enolate was not able to provide the anti isomer selectively. An X-ray crystal structure confirmed the absolute configuration of the product.
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36

Rinard, Chauncey J. "I. An Unusual Hydride Transfer in the Thermolysis of a Lithium Alkoxide ; II. Carbon-Carbon Bond Forming Reactions of Oxidized Anilide Intermediates. A New Route to Dihydroindoles /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487935125878439.

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37

Pareek, Manish [Verfasser], Martin [Akademischer Betreuer] Oestreich, Martin [Gutachter] Oestreich, and Philipp [Gutachter] Heretsch. "Activation of boron–boron, tin–silicon, and tin–tin bonds : application in carbon–element (E = B and Sn) bond-forming reactions and site-selective Suzuki–Miyaura cross-coupling reactions / Manish Pareek ; Gutachter: Martin Oestreich, Philipp Heretsch ; Betreuer: Martin Oestreich." Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156016843/34.

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38

Kerns, Michael Lester. "I. A Model System for the Anodic Oxidation of 4-(2'- Alkenylphenyl)Phenols: Evidence for a Phenoxonium Ion Intermediate II. Carbon-Carbon Bond Forming Reactions of Oxidized Phenol Intermediates with Vinyl Sulfides III. Naphthopyran Quinone.. /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487930304684744.

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39

Sugawara, Masanobu. "Cationic Carbon-Carbon Bood Forming Reactions Controlled by an Organothio or-stannyl Group." Kyoto University, 1999. http://hdl.handle.net/2433/181333.

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Chu, Wai-cheung. "Syntheses and reactions of copper and manganese complexes of tetradentate polyanionic chelating ligands and their applications in carbon-heteroatom bond formation reactions /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19324893.

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41

Nicolae, Toma Gabriel. "Cobalt-Catalyzed Carbon-Nitrogen Bond-Forming Reaction between Secondary Amines and N-Aromatic or Aromatic Chlorides." Kyoto University, 2011. http://hdl.handle.net/2433/142304.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(人間・環境学)
甲第16176号
人博第559号
新制||人||134(附属図書館)
22||人博||559(吉田南総合図書館)
28755
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 山口 良平, 教授 田村 類, 准教授 藤田 健一
学位規則第4条第1項該当
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42

Tsui, Chit. "New Synthetic Applications of Rhodium-Catalyzed Carbon-Carbon and Carbon-Heteroatom Bond Forming Reactions." Thesis, 2013. http://hdl.handle.net/1807/36019.

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This thesis is divided into four chapters that describe the new development in rhodium-catalyzed addition reactions and asymmetric ring opening (ARO) reactions of strained alkenes. Chapter 1 describes a regioselective Rh(I)-catalyzed addition reaction of arylboronic acids to unactivated alkenes - protected allylic amines and allyl sulfones. These formal hydroarylation processes have significantly advanced the substrate scope. Comprehensive studies were carried out to optimize the reaction conditions and a wide range of arylboronic acids were employed. The reaction was found to be linear-selective and a mechanism based on functional group- directing effects has been proposed. Chapter 2 discloses the discovery of Rh(I)-catalyzed addition of arylboronic acids to (benzyl- /arylsulfonyl)acetonitriles. Novel β-sulfonylvinylamine products were formed in a stereoselective fashion (Z-alkene). Upon hydrolysis, β-keto sulfones were obtained with a broad scope of aryl and sulfonyl substituents. These (Z)-β-sulfonylvinylamines were useful synthons in the synthesis of unsymmetrical polysubstituted pyridines via 1-aza-allyl anion intermediates as well as 1,4- benzothiazine derivatives via intramolecular cyclization. Chapter 3 reports the use of two new nucleophiles in Rh(I)-catalyzed ARO of oxabicyclic alkenes - water and triethylamine trihydrofluoride. In the water-induced ARO, an unprecedented domino ARO/isomerization process was discovered which led to the formation of 2-hydroxy-1- tetralones. By modifying the reaction conditions, trans-1,2-diols can be obtained in excellent enantioselectivity. Using triethylamine trihydrofluoride as a nucleophile, an aliphatic C-F bond was constructed enantioselectively in the ring-opening process which provided fluorinated building blocks containing both allylic fluoride and fluorohydrin units. Finally, Chapter 4 details the development of a one-pot synthesis of a chiral dihydrobenzofuran framework using Rh-catalyzed asymmetric ring opening and Pd-catalyzed C-O coupling. The product can be obtained in excellent enantioselectivity without isolation of intermediates. Systematic metal-ligand studies were carried out to investigate the compatibility of each catalytic system using product enantiopurity as an indicator.
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Dhineshkumar, J. "Iodine and Copper Catalyzed Oxidative Cross Coupling Reactions : Design and Development of Carbon-Carbon and Carbon-Heteroatom Bond Forming Reactions." Thesis, 2016. http://hdl.handle.net/2005/3020.

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Design and Development of Carbon-Carbon and Carbon-Heteroatom Bond Forming Reactions” is divided into two sections. Section-A, contains two chapters, describes the catalytic ability of iodine for cross coupling reactions. Section-B, divided into three chapters, presents the azidation of organic scaffolds under oxidative conditions. Section A Chapter 1 presents a C-H functionalization of tetrahydroisoquinolines using iodine as a catalyst under aerobic conditions.1 This methodology employs Cross Dehydrogenative Coupling (CDC) strategy as a key step, which is highly atom economical as it doesn’t require pre-functionalized starting materials.2 Owing to the importance of tetrahydroisoquinoline moiety which is present in the umpteen natural products, considerable attention has been put up to functionalize tetrahydroisoquinoline scaffold.3 Iodine a non-metal which is non-toxic was found to catalyze the C-H functionalization of tetrahydroisoquinolines with a variety of nucleophiles such as coumarin, alkyl phosphite, phenols, indoles, acetone and dialkyl malonoates were coupled to it. Significant mechanistic study has been carried out to find the possible intermediate and support the mechanistic proposal. A few representative examples are highlighted in Scheme 1.1 Synopsis Scheme 1: A CDC coupling of tetrahydroisoquinoline with variety of nucleophiles Chapter 2 describes the Cross Hetero Dehydrogenative Coupling (CHDC) reactions of amines, alcohols and sulfoximines with various phosphites.4 Phosphoramidates and phosphate esters are structural scaffolds that are present in a variety of biologically active molecules.5 The conventional methods for synthesizing phosphoramidates/phosphate esters largely involve treating alcohol/amine with appropriate phosphorus halides which generates stoichiometric amount of halogen waste.6 Due to the usage of stoichiometric reagents and difficulties associated with the reported methods, there is a need for developing a protocol which is catalytic and mild. Therefore, we developed a method which employs catalytic amount of iodine and aq. H2O2 as a sole oxidant under milder conditions. Using this methodology, variety of phosphoramidates, phosphorous triesters and sulfoximine derived Synopsis Scheme 2: Phosphorylation of amines, alcohols and sulfoximines phosphoramidates have been synthesized with great efficiency and environmentally benign conditions. A few representative examples are highlighted in Scheme 2.4 Section B Chapter 1 of Section B demonstrates a mild way of synthesizing quaternary azides from α-substituted active methylene compounds which will serve as surrogates for several unnatural amino acid derivatives.7 Azidation has emerged as one of the efficient methods to introduce nitrogen atom in to the organic molecules.8 Azides are versatile functional groups which can be converted to amine, amide, and nitro compounds by simple modification. Moreover, azides are potential handle for “click” chemistry and provide late stage modifications in drug candidates, biomolecules and polymers, etc.9 Azidation of 1,3-dicarbonyl compounds is challenging, as both azides and 1,3-dicarbonyl compounds are nucleophilic in nature. In this section of the thesis, azidation of 1,3-dicarbonyl compounds has been carried out using tetrabutyl ammonium iodide (TBAI) as a catalyst, aq. TBHP as an oxidant and TMSN3 as a azide source. This method uses water as a solvent under mild reaction conditions to generate Synopsis quaternary azides in good to excellent yields. This operationally simple, practical, mild and green method provides an opportunity for synthesizing a variety of azidated β-keto esters, amides and ketones in good yields, Scheme 3.7 The application of this methodology has been demonstrated by synthesising a few triazole and pyrazolone derivatives. Scheme 3: Azidation of 1,3-dicarbonyl compounds Chapter 2 of Section B comprises the azidation and peroxidation of β-napthol derivatives using dearomatization strategy. Azidation and peroxidation are efficient ways to introduce nitrogen and oxygen into organic molecules, which serve as surrogates for amines and alcohol functional groups. In the present study, the azidative or peroxidative dearomatization of naphthol derivatives have been described. The azidation of β-napthol derivatives has been achieved by using CuBr (5 mol %) as a catalyst, TMSN3 as an azide source and aq. TBHP as an oxidant. Whereas, the peroxidation β-napthol derivatives has been accomplished using CuBr (5 mol %) in the presence of aq. TBHP at ambient reaction conditions.10 The products obtained are naphthalenone derivatives, which serve as valuable Synopsis synthetic intermediates and has potential handle for further functionalization.11 Several α-amino or α-peroxy naphthalenones are synthesized using this method in good yields. The usefulness of the methodology has been illustrated by synthesizing a few chiral azides and peroxides in good yields and with moderate enantioselectivity Scheme 4.10 Scheme 4: Dearomatizative azidation and peroxidation of 2-naphthols Chapter 3 reveals the azidation of indole at C-2 position by employing CuBr (10 mol %) as a catalyst and aq. TBHP as an oxidant in acetonitrile under reflux conditions (Scheme 5).12 The C-H functionalization of indole at C-2 position is one of pivotal methods, since it paves a way for synthesizing a variety of indolo-alkaloids.13 Azide is a versatile functionality which can be converted to several other nitrogen containing functional groups such as Synopsis Scheme 5: Azidation of indoles amine, amide, triazole, etc.9 A variety of functional groups were tolerated under the reaction conditions, and furnished the azidated product in good to excellent yields. Through radical inhibition study, we presume that the reaction may be proceeding through radical mechanism. In Scheme 5, a few representative examples are depicted.
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44

Widdowson, Katherine. "Silicon-directed carbon-carbon bond forming reactions." Thesis, 1992. https://thesis.library.caltech.edu/6693/1/Widdowson_k_1992.pdf.

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It is shown that O-silyl ketene N,O-acetals react with aldehydes, without catalysis, to form aldol-type products with high diastereoselectivity. For example, the prolinolderived O-silyl ketene N,O-acetal 7 reacts with benzaldehyde to form the anti aldol product 9 with >98% diastereoselectivity. Mechanistic studies are presented which support a scheme involving formation of trigonal bipyrarnid (tbp) G, pseudorotation to form tbp T_(boat), and rate-determining C-C bond formation to produce 9.

It is shown that aldehydes react with pyridine, benzeneselenol, dichlorodimethylsilane, and an allylic alcohol to form O-allyloxy dimethylsilyl hemiselenoacetals in high yield. These derivatives undergo efficient free radical-mediated cyclization upon treatment with BU_3SnH, as exemplified by the transformation of 7→8. Together these steps provide an efficient method for carbon-carbon bond formation between the carbonyl carbon of an aldehyde and the terminus of an allylic alcohol.

2,3-Epoxy alcohols are transformed to C2-inverted cyclic carbonates upon treatment with cesium carbonate under an atmosphere of carbon dioxide (e.g., 5→6).The reaction is completely stereospecific, within experimental error, and forms only 5-membered ring cyclic carbonates.

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45

BERRINO, ROBERTA. "Studies on the transition metal-catalyzed C-C and C-heteroatom bond forming reactions." Doctoral thesis, 2012. http://hdl.handle.net/11573/918824.

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46

Zbieg, Jason Robert. "Controlling selectivity in novel transition metal catalyzed carbon-carbon bond forming hydrogenations." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5047.

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The focus of my graduate research in the Krische group has been the development of catalytic carbon-carbon bond forming reactions with an emphasis on controlling diastereo- and enatio-selectivity in transfer hydrogenative couplings. The broad goal of our research program has been the development and implementation of efficient green methods for carbonyl addition employing [pi]-unsaturates as surrogates to preformed organometallic reagents, thus enabling byproduct free variants of traditional carbanion chemistry. This dissertation shows the new reactions that I have developed toward this goal. These reactions includes new metal catalyzed approaches for carbonyl crotylation, aminoallylation, and vinylogous reformatsky aldol reactions.
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47

浅井, 学文, and Takafumi Asai. "Design of Chiral Supramolecular Catalysts for Asymmetric Carbon–Carbon Bond–Forming Reactions." Thesis, 2009. http://hdl.handle.net/2237/14813.

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48

Komanduri, Venukrishnan. "Development of transition-metal catalyzed/mediated reductive carbon-carbon bond forming reactions." Thesis, 2009. http://hdl.handle.net/2152/ETD-UT-2009-08-342.

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Carbon-Carbon bond forming reactions are very important in organic synthesis. Preparation of most of the leading drugs on the market involves at least one carbon-carbon bond forming transformation. However, use of preformed oganometallics for this purpose is neither atom economical nor cost effective. Thus, development of atom economical and environmentally benign carbon-carbon bond forming methods is highly desirable. Catalytic hydrogenation is one of the most widely used transformations in the pharmaceutical and chemical industry. However, for several years the catalytic hydrogenation was limited to the carbon-carbon bond forming processes such as alkene hydroformylation and the Fischer-Tropsch reactions. In 2004 Krische group demonstrated a novel reductive aldol cyclization under rhodium catalyzed hydrogenation conditions. Following this, a variety of reductive carbon-carbon bond forming reactions were developed under hydrogenation conditions. The first chapter of this dissertation summarizes the reductive couplings of π-unsaturates to imines. N-heterocyclic compounds are very valuble in pharmaceutical and agrochemical industries. In the second chapter a variety of hydrogen mediated reductive couplings to aromatic N-heterocycles have been described. Transfer hydrogenation represents another important class of reactions in organic chemistry. This process employs hydrogen sources other than gaseous dihydrogen, such as isopropanol. Very recently, the Krische group reported a number of novel C-C coupling reactions using the concept of transfer hydrogenation. Thus, in chapter 3 a very elegant ruthenium catalyzed allylation reaction has been described. Finally, chapter 4 focuses on the reactivity of zinc enolates toward less reactive electrophiles such as allylic carbonates in the absence of any transition metal catalyst. During this process a direct allylic substitution of allylic carbonates with diorganozinc reagents has been discovered. These two transformations are conceptually very interesting.
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49

Wang, Wei-Lin, and 王薇琳. "Carbon - Carbon Bond Forming Reactions of Nitrenium Ions Generated from Aceton - Anile." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/52501039354178880910.

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Wysong, Ernest Byron. "Investigations of group IVA transition metal mediated carbon-carbon bond forming reactions." Thesis, 1990. https://thesis.library.caltech.edu/8788/1/Wysong-eb-1990.pdf.

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Zirconocene aldehyde and ketone complexes were synthesized in high yield by treatment of zirconocene acyl complexes with trimethylaluminum or diisobutylaluminum hydride. These complexes, which are activated by dialkylaluminum chloride ligands, inserted unsaturated substrates such as alkynes, allenes, ethylene, nitriles, ketenes, aldehydes, ketones, lactones, and acid chlorides with moderate to high conversion. Insertion of aldehyde substrates yielded zirconocene diolate complexes with up to 20:1 (anti:syn) diastereoselectivity. The zirconocene diolates were hydrolyzed to afford unsymmetrical 1,2-diols in 40-80% isolated yield. Unsymmetrical ketones gave similar insertion yields with little or no diastereoselectivity. A high yielding one-pot method was developed that coupled carbonyl substrates with zirconocene aldehyde complexes that were derived from olefins by hydrozirconation and carbonylation. The zirconocene aldehyde complexes also inserted carbon monoxide and gave acyloins in 50% yield after hydrolysis.

The insertion reaction of aryl epoxides with the trimethylphoshine adduct of titanocene methylidene was examined. The resulting oxytitanacyclopentanes were carbonylated and oxidatively cleaved with dioxygen to afford y-lactones in moderate yields. Due to the instability and difficult isolation of titanocene methylidene trimethylphoshine adducts, a one-pot method involving the addition of catalytic amounts of trimethylphosphine to β,β-dimethyltitanacyclobutane was developed. A series of disubstituted aryl epoxides were examined which gave mixtures of diastereomeric insertion products. Based on these results, as well as earlier Hammett studies and labeling experiments, a biradical transition state intermediate is proposed. The method is limited to aryl substituted epoxide substrates with aliphatic examples showing no insertion reactivity.

The third study involved the use of magnesium chloride supported titanium catalysts for the Lewis acid catalyzed silyl group transfer condensation of enol silanes with aldehydes. The reaction resulted in silylated aldol products with as many as 140 catalytic turnovers before catalyst inactivation. Low diastereoselectivities favoring the anti-isomer were consistent with an open transition state involving a titanium atom bound to the catalyst surface. The catalysts were also used for the aldol group transfer polymerization of t-butyldimethylsilyloxy-1-ethene resulting in polymers with molecular weights of 5000-31,000 and molar mass dispersities of 1.5-2.8. Attempts to polymerize methylmethacrylate using GTP proved unsuccessful with these catalysts.

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