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Teses / dissertações sobre o tema "Metalation"

Autor: Grafiati

Publicado: 4 de junho de 2021

Última modificação: 20 de abril de 2024

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1

Timmons, Michael. "Directed Ortho-Metalation of Dimethylarylamines". TopSCHOLAR®, 2002. http://digitalcommons.wku.edu/theses/641.

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Site-specific product(s) from the reaction of benzene derivatives with various reagents is a need of researchers at numerous laboratories, particularly those in the pharmaceutical industry. Such derivatives can be synthesized directly, i.e., by substitution of a proton, using either of two procedures: electrophilic aromatic substitution (EAS) or directed ortho-metalation (DoM). Directed ortho-metalation (DoM) is an alternative aromatic substitution process initiated by organolithium reagents which provides regiospecific substitution exclusively at the ortho- position (equation). The focus of this study is to find hydrocarbon media that will permit the maximum extent of metalation of several dimethylarylamines. The dimethylamine-containing substituents constitute directing metalation groups (DMG's) for the various aryl systems investigated. Maximization of the extents of ortho-lithiation of dimethylaniline [DMG = - N(CH3)2] and dimethylbenzylamine [DMG = -CH2N(CH3)2] have now been achieved using novel combinations of solvent, temperature and increments of catalyst. Studies of substituted dimethylanilines and dimethylbenzylamines containing a second DMG have yielded mixed results. Both metalation condition parameters as well as certain mechanistic aspects are altered by inclusion of a second DMG into these two parent systems.

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2

Campbell, Smith Alison May. "Controlling directed metalation in aromatic systems". Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610077.

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3

Shelton, Phillip. "Metalation of the Di- and Tri-Methoxybenzenes". TopSCHOLAR®, 2001. http://digitalcommons.wku.edu/theses/701.

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Hydrocarbon solvents are known to be unreactive towards organolithium reagents and also to afford little support for ortho-metalation reactions. In contrast, both m- and odimethoxybenzene afford 80% "ion-multiple specific" monometalation in hydrocarbon solvent (n-hexane, cyclohexane, toluene) without the addition of any catalyst (ether or amine). These observations are, in part, attributed to the 1,2- and 1,3- formation of the n-BuLi dimer, the most reactive form of n-BuLi. In other words these substrates are acting in a "substrate-catalyzed" manner. Extensions of these concepts to 1,2,3-, 1,2,4- and 1,3,5-trimethoxybenzenes have led to further unusual observations. In particular, the 1,2,3-system affords an interesting nucleophilic aromatic substitution reaction. This autocatalytic mode of ortho-metalation offers additional insight into the controversy regarding the participation of a dimer intermediate in the mechanism of the directed ortho-metalation reaction.

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4

Cai, Xiongwei. "Regiospecific synthesis of alkylphenanthrenes using a combined directed ortho metalation, DoM, (Suzuki-Miyaura cross coupling), directed remote metalation, DreM, methodology". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63276.pdf.

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5

Woosley, Barry. "Directed ortho Metalation in Hydrocarbon Solvents: Opposing Pi-Resonance Effects". TopSCHOLAR®, 2004. http://digitalcommons.wku.edu/theses/539.

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Hydrocarbon solvents are known to be unreactive toward organolithium reagents and do not typically support ortho-metalation reactions without the aid of a promoter. An exception would be an arene substrate having the capability to bidentate complex to the reactive alkyllithium dimer, which enables ortho-metalation to occur in high yields. A second, more limiting exception, would be that the arene substrate possesses localized lone pairs of electrons, as is the case when the directed ortho metalating group (DMG) is located in the benzyl position. The work reported here centers upon developing a third and larger class of arene substrates that are exceptions to the general rule that metalation in hydrocarbon solvents requires the use of added promoter. When an arene is either 1,2- or 1,4- disubstituted with electron donating DMGs, the lone pairs of electrons on each of the DMG groups are more localized than is the case for a monosubstituted arene. The effect of localization allows the arene to complex more efficiently and therefore metalate. This localization effect we term the Opposing Pi Resonance Effect.

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6

Friesen, Carl. "Directed Ortho-Metalation of the Three Methyl Anisoles in Various Media". TopSCHOLAR®, 1996. http://digitalcommons.wku.edu/theses/870.

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Directed ortho-metalation (DoM) is a very useful alternative to electrophillic aromatic substitution (EAS) for the synthesis of substituted aromatic compounds. DoM is highly regiospecific providing metalation chiefly in the ortho-position. However, lateral (a-) metalation of an alkyl side-chain and ortho-metalation of a second ortho-position can compete. Investigation of the three methylanisoles was therefore undertaken to determine the interplay between these factors and to discover metalation conditions to achieve selectivity. This goal was uniquely achieved for p-methylanisole where conditions were discovered which allowed > 85% ortho-metalation as determined by GC analysis with virturally no competing lateral metalation. Three derivitives of this ortho-lithio intermediate were prepared, each in > 75% yield. Metalation conditions were found that permitted significant descrimination between 2- and 6- position metalation of m-methylanisole. Metalation conditions were also found that permitted regiospecific a-metalation of o-methylanisole.

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7

Milburn, Claire Louise Maud Jackson. "The directed ortho metalation reaction of aryl O-carbamates on solid support". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63340.pdf.

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8

Panighel, Mirco. "Adsorption, metalation and magnetic properties of tetra phenyl porphyrins on metal surfaces". Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10898.

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2013/2014
Traditional semiconductor technology will reach a size limit within the next few years. A possible solution could be the use of organic molecules in technological applications as single functional units in metal-organic based devices; the success of this approach strongly depends on the understanding of the behaviour of these molecules on metallic surfaces. The interaction with metallic substrates and the interaction between the molecules themselves determine the electronic and magnetic properties of the system, and it is thus of fundamental interest to study these metal-organic interfaces both in the case of single molecules and layer structures. In this thesis, an extensive study of the electronic and magnetic properties of tetra-phenyl-porphyrin (2H-TPP) molecules adsorbed on metal surfaces is reported. By means of scanning tunnelling microscopy (STM) we studied the adsorption geometry of these molecules on the Au(111), Ag(111) and Cu(100) surfaces. By using X-ray photoemission spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, a temperature-induced conformational adaptation reaction of the 2H-TPP molecules adsorbed on the Au(111) and Ag(111) surfaces, upon annealing at 550 K, is described. A possible dehydrogenation reaction, with the formation of new C-C bonds, could explain the rotation of the molecule phenyl rings parallel to the surface plane and the associated increasing in the molecule-substrate interaction. In-situ metalation of porphyrins in ultra-high vacuum is obtained by two methods: in the first one, the metalation of 2H-TPP on Ag(111) is achieved by direct metal evaporation (Mn, Rh and Fe) on the molecular layer; in the second case we report the self-metalation of 2H-TPP through the coordination with a metal atom from the Fe(110) and Al(111) substrates. In addition, we investigated the effects of metalation and temperature-induced conformational adaptation on the molecule-substrate interaction, by means of XPS and NEXAFS, in the case of CoTPP on Ag(111). The magnetic properties resulting from the metal coordination are studied by X-ray magnetic circular dichroism (XMCD). Here, a description of the magnetic coupling of a MnTPPCl single layer with a Fe(110) ferromagnetic substrate is disclosed. Moreover, we focused on the study of the magnetic properties and exchange coupling of two layer of molecule and a ferromagnetic thin film. In the case of a MnTPP layer on FeTPP/Fe(110) the magnetic coupling extends to the second layer of molecules, for which the magnetization is opposite with respect to the substrate.
Le tradizionali tecnologie utilizzate nell’industria dei semiconduttori raggiungeranno, entro breve tempo, il limite nella miniaturizzazione dei loro componenti. Una possibile alternativa potrebbe venire dall’utilizzo di molecole organiche come singole unità funzionali in dispositivi metallo-organici; d’altra parte il successo di questo approccio dipende in maniera sostanziale dalla comprensione del comportamento di queste molecole sulle superfici dei metalli. L’interazione con il substrato metallico e la stessa interazione tra le molecole determinano le proprietà elettroniche e magnetiche di questi sistemi, ed è dunque di fondamentale interesse lo studio di queste interfacce metallo-organiche sia nel caso di singole molecole che di strutture più complesse. In questa tesi è riportato uno studio dettagliato delle proprietà elettroniche e magnetiche di tetra-fenil-porfirine (2H-TPP) adsorbite su superfici metalliche. Attraverso la microscopia a scansione a effetto tunnel (STM) è stata studiata la geometria di adsorbimento di queste molecole sulle superfici Au(111), Ag(111) e Cu(100). Utilizzando le spettroscopie XPS (X-ray photoemission spectroscopy) e NEXAFS (near-edge X-ray absorption fine structure) è descritta la reazione di adattamento conformazionale delle 2H-TPP adsorbite sulle superfici Au(111) e Ag(111) a seguito del processo di annealing a 550 K. Una possibile reazione di de-idrogenazione, con la formazione di nuovi legami C-C, può spiegare la rotazione dei gruppi fenili della molecola verso la superficie e l’aumento dell’interazione molecola-substrato ad esso associato. La metallazione in-situ delle porfirine in ultra-alto vuoto è ottenuta in due modi: nel primo, la metallazione delle 2H-TPP su Ag(111) è raggiunta con la diretta evaporazione del metallo (Mn, Rh e Fe) sullo strato di molecole; nel secondo caso, sulle superfici Fe(110) e Al(111) la metallazione avviene automaticamente tramite la coordinazione della 2H-TPP con un atomo della superficie. Inoltre, gli effetti della metallazione e dell’adattamento conformazionale sull’interazione molecola-substrato sono stati studiati, tramite XPS e NEXAFS, nel caso di CoTPP su Ag(111). Le proprietà magnetiche risultanti dalla coordinazione della molecola con un atomo metallico sono state studiate per mezzo della tecnica XMCD (X-ray magnetic circular dichroism). In particolare, viene descritto l’accoppiamento magnetico di un singolo strato di MnTPPCl con un substrato ferromagnetico Fe(110). Inoltre, ci si è focalizzati sullo studio delle proprietà magnetiche tra due strati di molecole e un film sottile ferromagnetico. Nel caso specifico di MnTPP su FeTPP/Fe(110) l’accoppiamento magnetico si estende al secondo strato di molecole, per il quale la magnetizzazione è opposta rispetto al substrato.
XXVII Ciclo
1986

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9

Macklin, Todd Kristopher. "The development of sulfamates as latent directed metalation groups. Total synthesis of schumanniophytine. Divergent synthesis of substituted chromone 3- and 8-carboxamides". Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/925.

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10

Fässler, Roger. "The metalation of terminal alkynes by Zn" and their addition to nitrones and aldehydes /". Zürich : [s.n.], 2003. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14936.

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11

Zegke, Markus. "Reductive metalation of the uranyl oxo-groups with main Group-, d- and f-block metals". Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/16186.

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This thesis describes the reductive functionalisation of the uranyl(VI) dication by metalation of the uranyl oxo-groups (O=UVI=O), using reductants from Group I, Group II, Group IV, Group XII and Group XIII as well as from the lanthanide and actinide series of the periodic table. Chapter 1 introduces uranium and nuclear waste, and gives an introduction into uranium(V) chemistry. It further compares the chemistry of uranyl(V) to neptunyl(V), with a specific focus on solid state interactions. The chemistry of the Pacman calixpyrroles is briefly introduced. These macrocyclic ligands form the basis for the synthesis of uranyl Pacman, which represents the major uranyl complex investigated in this thesis. Chapter 2 describes the reductive and catalytic uranyl oxo-group metalation using Group XIII and Group I reagents. It presents the reductive uranyl alumination using di-(iso-butyl)-aluminium hydride and Tebbe’s reagent to form the first Al(III)- uranyl(V) oxo complexes (AlIII-O-UV=O). The chapter shows how the transmetalation of these aluminated uranyl(V) complexes with alkali metal hydrides and alkyls leads to the formation of mono-metalated alkali metal uranyl(V) complexes (MI-O-UV=O). The combination of these two reactions is developed into a catalytic synthesis of the latter. The use of elemental alkali metals is described as another pathway of accessing alkali metal uranyl(V) complexes, carried out in collaboration with Dr. Rianne M. Lord. Chapter 3 describes the synthesis of the first Group IV uranyl(V) complexes, using low-valent titanium and zirconium starting materials. The chapter includes magnetic measurements on the first Ti(III)-uranyl(V) complex and a comparison of computational results regarding a selection of uranyl(V) complexes from this thesis. The magnetic measurements were carried out by Dr. Alessandro Prescimone, University of Edinburgh, and analysed by Dr. Nicola Magnani, Institute for Transuranium Elements, Karlsruhe, Germany. Theoretical calculations were carried out by Xiaobin Zhang and Prof. Dr. Georg Schreckenbach, University of Manitoba, Canada. The chapter further describes the reductive metalation of uranyl using elemental Mg, Ca and Zn and their respective metal halides. Chapter 4 describes the uranyl functionalisation using f-elements and their complexes. It describes the attempted mono-metalation using lanthanides and the formation of a Sm(III)-bis(uranyl(V)) complex. It further describes the uranyl reduction using actinides and the synthesis of the first U(IV)-uranyl(V) complex. The chapter further describes the first Np(IV)-uranyl(V) complex and the attempted synthesis of a Pu(IV)-uranyl(V) complex. These syntheses were performed in collaboration with Michał S. Dutkiewicz at the Institute for Transuranium Elements (ITU) in Karlsruhe, Germany. This work was carried out with the help of Dr. Christos Apostolidis and Dr. Olaf Walter and supervised by Prof. Dr Roberto Caciuffo. Chapter 5 describes the reductive uranyl functionalisation in a redox-active dipyrromethene ligand, collaboratively carried out with James R. Pankhurst and Lucy N. Platts. The synthetic work and analyses were performed jointly with Lucy N. Platts (master student under the supervision of the author); UV-vis spectra and cyclic voltammograms were recorded by James R. Pankhurst and Lucy N. Platts. The chapter presents the synthesis of a new uranyl(VI) complex and its two-electron reduction to uranium(IV) using a titanium(III) reductant. Additionally the chapter describes the reductive uranyl silylation in a dipyrromethane complex of which the ligand was designed by Dr. Daniel Betz. Section 6 describes the synthetic procedures. Section 7 gives references to the work of others. Section 8 shows the publication related to this thesis. Section 9 is a table of the complexes described in this thesis.

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12

Kendall, Christopher Nicholas Owen. "The directed ortho metalation - Suzuki-Miyaura cross-coupling connection, towards the total synthesis of dehydrorabelomycin". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0020/MQ54462.pdf.

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13

Sousa, Alexandre Carreira da Cruz. "5,10,15,20-meso-tetrapiridilporfirina de európio: síntese, caracterização e investigações espectroscópicas". reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/20074.

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SOUSA, Alexandre Carreira da Cruz. 5,10,15,20-meso-tetrapiridilporfirina de európio: síntese, caracterização e investigações espectroscópicas. 2015. 62. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2015.
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Increasingly, porphyrins have gained a position of detached interest in scientific circles. Its high biological compatibility, being a molecule found naturally in plants and many red blood animals, coupled with the possibility of forming complexes with lanthanide atoms, makes these compounds are particularly attractive in a branch of medicine quite promising in terms respect to combat cancer, called photodynamic therapy. The lanthanide-porphyrin complex act as photosensitizers in the production of singlet oxygen, a cytotoxic species, may be soaked in organic tissue of interest, promoting the cancer cell death. The synthesis of some Ln-porphyrin complexes [Ln (Ln = Gd, Er, Yb)] are already reported in the literature. However, with increasing ionic radius of metal that is intended to complex in the porphyrin, the energy barrier which prevails opposite the occurrence of this synthesis also increases, hindering the occurrence of the metalation process. Thus, this study seeks to promote metalation with europium, in 5,10,15,20 - meso - tetrapyridilporphyrin (H2TPyP). Was used the europium acetylacetonate salt [Eu(acac)3] in the synthesis as a source of Eu3+ ion. The obtained compound was purified by column chromatography on elution of alumina (Al2O3) and further characterized by absorption spectroscopy in the ultraviolet-visible region (UV-VIS) and infrared region (IR), luminescence and termogravimetric analysis (TG). The results obtained for the UV-vis spectra show for complex synthesized 3 Q bands, a lower number compared to the spectrum of the free base porphyrin, which has 4 Q bands, which discloses the formation of a compound with higher symmetry, which rose from D2h to D4h due to insertion of the metal ion in the porphyrin ring. It was observed also a bathochromic shift of the Soret band in the complex shifted from 417 to 429nm, consistent with the fact that the metallation occurred. The IR results and suggest the occurrence of metalation of the suppression band 3304cm-1, indicating deprotonation of the central atoms of Nytrogen, also suggested maintaining the acetylacetonate ion in stabilizing the structure of the complex. The luminescence showed that there was enhancement of emission bands, which is consistent with the formation of a metal complex. In the TG results, it was found that the compound formed to the amount of residue obtained was much higher than that for H2TPyP, suggesting the formation of metal oxide in the first case, consistent with the fact that formation of europium metalloporphyrin.
Cada vez mais, as porfirinas vêm conquistando uma posição de destacado interesse no meio científico. Sua elevada compatibilidade biológica, sendo uma molécula encontrada naturalmente em plantas e em diversos animais de sangue vermelho, aliada a possibilidade da formação de complexos com átomos de lantanídeos, faz com que esses compostos sejam particularmente atrativos em um ramo bastante promissor da medicina no que diz respeito ao combate ao câncer, denominado de terapia fotodinâmica. Isso porque os complexos lantanídeos-porfirina atuam como fotossensibilizadores na produção de oxigênio singlete, uma espécie citotóxica, podendo esses complexos serem saturados em tecidos orgânicos de interesse, promovendo a morte de células cancerígenas. A síntese de alguns complexos Ln-porfirina (Ln= Gd, Er, Yb) já são reportadas na literatura. Entretanto, com o aumento do raio iônico do metal que se pretende complexar a porfirina, a barreira energética que se impera frente a ocorrência desta síntese também aumenta, dificultando a ocorrência do processo de metalação. Dessa forma, o presente estudo busca promover a metalação de európio na 5,10,15,20 – meso – tetrapiridilporfirina (H2TPyP). Utilizou-se o sal acetilacetonato de európio [Eu(acac)3] na síntese como fonte do íon Eu3+. O composto obtido foi purificado por eluição em coluna cromatográfica de alumina (Al2O3) e posteriormente caracterizado por espectroscopia de absorção na região do ultravioleta-visível (UV-Vis) e infravermelho (IR), luminescência e análise termogravimética (TG). Os resultados obtidos por UV-Vis para o complexo sintetizado mostraram espectros com 3 bandas Q, um menor número comparado ao espectro da porfirina base livre que apresenta 4 bandas Q, o que sugere a formação de um composto com maior simetria, que passou de D2h para D4h, devido a inserção do íon metálico no anel porfirínico. Observou-se também um deslocamento batocrômico da banda Soret no complexo que deslocou de 417 para 429nm, fato condizente com a ocorrência da metalação. Os resultados de IR, além de sugerirem a ocorrência da metalação pela supressão da banda em 3304cm-1, indicando a desprotonação dos nitrogênios centrais, também sugeriram a manutenção do íon acetilacetonato na estabilização da estrutura do complexo. A luminescência mostrou que houve intensificação das bandas de emissão, o que condiz com a formação de um complexo metálico. Nos resultados de TG constatou-se que para o composto formado a quantidade de resíduo obtido foi bastante superior de que para a H2TPyP, sugerindo a formação de óxido metálico no primeiro caso, fato condizente com a formação da metaloporfirina de európio.

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14

Metallinos, Constantinos. "Development of new directed metalation groups for the (-)-sparteine-mediated synthesis of ferrocenes with planar chirality". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63438.pdf.

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15

Lai, Ping-Shan. "Directed ortho metalation-boronation Suzuki-Miyaura cross coupling leading to synthesis of azafluorenol core liquid crystals". Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/511.

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16

Miller, Ricarda [Verfasser]. "Directed remote Metalation Strategy : Synthesis, Cytotoxicity and DNA-Intercalation of Arnottin I and Schumanniophytine Derivatives / Ricarda Miller". Konstanz : Bibliothek der Universität Konstanz, 2011. http://d-nb.info/1049892801/34.

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17

Sousa, Alexandre Carreira da Cruz. "5,10,15,20-meso-tetrapiridilporphyrin europium: synthesis, characterization ans spectroscopic investigations". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14722.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Increasingly, porphyrins have gained a position of detached interest in scientific circles. Its high biological compatibility, being a molecule found naturally in plants and many red blood animals, coupled with the possibility of forming complexes with lanthanide atoms, makes these compounds are particularly attractive in a branch of medicine quite promising in terms respect to combat cancer, called photodynamic therapy. The lanthanide-porphyrin complex act as photosensitizers in the production of singlet oxygen, a cytotoxic species, may be soaked in organic tissue of interest, promoting the cancer cell death. The synthesis of some Ln-porphyrin complexes [Ln (Ln = Gd, Er, Yb)] are already reported in the literature. However, with increasing ionic radius of metal that is intended to complex in the porphyrin, the energy barrier which prevails opposite the occurrence of this synthesis also increases, hindering the occurrence of the metalation process. Thus, this study seeks to promote metalation with europium, in 5,10,15,20 - meso - tetrapyridilporphyrin (H2TPyP). Was used the europium acetylacetonate salt [Eu(acac)3] in the synthesis as a source of Eu3+ ion. The obtained compound was purified by column chromatography on elution of alumina (Al2O3) and further characterized by absorption spectroscopy in the ultraviolet-visible region (UV-VIS) and infrared region (IR), luminescence and termogravimetric analysis (TG). The results obtained for the UV-vis spectra show for complex synthesized 3 Q bands, a lower number compared to the spectrum of the free base porphyrin, which has 4 Q bands, which discloses the formation of a compound with higher symmetry, which rose from D2h to D4h due to insertion of the metal ion in the porphyrin ring. It was observed also a bathochromic shift of the Soret band in the complex shifted from 417 to 429nm, consistent with the fact that the metallation occurred. The IR results and suggest the occurrence of metalation of the suppression band 3304cm-1, indicating deprotonation of the central atoms of Nytrogen, also suggested maintaining the acetylacetonate ion in stabilizing the structure of the complex. The luminescence showed that there was enhancement of emission bands, which is consistent with the formation of a metal complex. In the TG results, it was found that the compound formed to the amount of residue obtained was much higher than that for H2TPyP, suggesting the formation of metal oxide in the first case, consistent with the fact that formation of europium metalloporphyrin.
Cada vez mais, as porfirinas vÃm conquistando uma posiÃÃo de destacado interesse no meio cientÃfico. Sua elevada compatibilidade biolÃgica, sendo uma molÃcula encontrada naturalmente em plantas e em diversos animais de sangue vermelho, aliada a possibilidade da formaÃÃo de complexos com Ãtomos de lantanÃdeos, faz com que esses compostos sejam particularmente atrativos em um ramo bastante promissor da medicina no que diz respeito ao combate ao cÃncer, denominado de terapia fotodinÃmica. Isso porque os complexos lantanÃdeos-porfirina atuam como fotossensibilizadores na produÃÃo de oxigÃnio singlete, uma espÃcie citotÃxica, podendo esses complexos serem saturados em tecidos orgÃnicos de interesse, promovendo a morte de cÃlulas cancerÃgenas. A sÃntese de alguns complexos Ln-porfirina (Ln= Gd, Er, Yb) jÃ sÃo reportadas na literatura. Entretanto, com o aumento do raio iÃnico do metal que se pretende complexar a porfirina, a barreira energÃtica que se impera frente a ocorrÃncia desta sÃntese tambÃm aumenta, dificultando a ocorrÃncia do processo de metalaÃÃo. Dessa forma, o presente estudo busca promover a metalaÃÃo de eurÃpio na 5,10,15,20 â meso â tetrapiridilporfirina (H2TPyP). Utilizou-se o sal acetilacetonato de eurÃpio [Eu(acac)3] na sÃntese como fonte do Ãon Eu3+. O composto obtido foi purificado por eluiÃÃo em coluna cromatogrÃfica de alumina (Al2O3) e posteriormente caracterizado por espectroscopia de absorÃÃo na regiÃo do ultravioleta-visÃvel (UV-Vis) e infravermelho (IR), luminescÃncia e anÃlise termogravimÃtica (TG). Os resultados obtidos por UV-Vis para o complexo sintetizado mostraram espectros com 3 bandas Q, um menor nÃmero comparado ao espectro da porfirina base livre que apresenta 4 bandas Q, o que sugere a formaÃÃo de um composto com maior simetria, que passou de D2h para D4h, devido a inserÃÃo do Ãon metÃlico no anel porfirÃnico. Observou-se tambÃm um deslocamento batocrÃmico da banda Soret no complexo que deslocou de 417 para 429nm, fato condizente com a ocorrÃncia da metalaÃÃo. Os resultados de IR, alÃm de sugerirem a ocorrÃncia da metalaÃÃo pela supressÃo da banda em 3304cm-1, indicando a desprotonaÃÃo dos nitrogÃnios centrais, tambÃm sugeriram a manutenÃÃo do Ãon acetilacetonato na estabilizaÃÃo da estrutura do complexo. A luminescÃncia mostrou que houve intensificaÃÃo das bandas de emissÃo, o que condiz com a formaÃÃo de um complexo metÃlico. Nos resultados de TG constatou-se que para o composto formado a quantidade de resÃduo obtido foi bastante superior de que para a H2TPyP, sugerindo a formaÃÃo de Ãxido metÃlico no primeiro caso, fato condizente com a formaÃÃo da metaloporfirina de eurÃpio.

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18

Kachel, Stefan Renato [Verfasser], e J. Michael [Akademischer Betreuer] Gottfried. "Investigations of Metal/Organic Interfaces and Metalation Reactions of Organic Semiconductors / Stefan Renato Kachel ; Betreuer: J. Michael Gottfried". Marburg : Philipps-Universität Marburg, 2020. http://d-nb.info/1224046862/34.

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19

Rohbogner, Christoph. "TMP2Mg•2LiCl and Related Bases for the Metalation of Unsaturated Substrates and the Role of the Phosphorodiamidate Directing Group". Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-114575.

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20

Chauder, Brian Andrew. "Combined directed ortho metalation-transition metal catalyzed coupling reactions for the synthesis of chromenes, ergot alkaloids, and biaryl macrocycles". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ63410.pdf.

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21

Onuska, Nicholas Paul Ralph. "Studies Towards the Synthesis of 2,5-Disubstituted-3-Fluorothiophenes Using a Directed Ortho-Metalation/Nickel-Catalyzed Cross-Coupling Approach". Kent State University Honors College / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1460652408.

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22

Balkenhohl, Moritz [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Metalation and amination of N-heterocycles and the halogen/zinc exchange of aryl halides / Moritz Balkenhohl ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1211957128/34.

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23

James, Clint A. "The directed remote metalation-carbamoyl migration reaction, total syntheses of the defucogilvocarcins and Arnottin I and synthesis of heteroarylfused benzopyranones". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32833.pdf.

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24

Green, Anthony Laine. "The Directed ortho Metalation of pyridine derivatives with in situ boronation and links to the Suzuki-Miyaura cross coupling reaction". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ63310.pdf.

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25

Ganiek, Maximilian [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Metalation and Halogen-Lithium exchange of sensitive substrates and mild ester homologation in continuous flow / Maximilian Ganiek ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1172634327/34.

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26

Costa, Wijeendra M. R. S. "Coordination of Chemistry of Re(I) Carbonyl Complexes as Pharmaceutically Important Compounds and Synthesis, Characterization, and Metalation of Novel Phthalocyanine Analogs". University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1302492223.

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27

Langgaard, Kristensen Jesper. "Metalation, halogen-metal exchange and Pd(0) catalyzed cross-coupling reactions : application to the synthesis of substituted aromatic and heteroaromatic systems /". [Cph.] : Department of Medicinal Chemistry, Royal Danish School of Pharmacy, 2001. http://www.dfh.dk/phd/defences/previous2002.htm.

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28

Weidmann, Niels [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Preparation of lithium, sodium and potassium organometallics by metalation and halogen/metal exchange in continuous flow / Niels Weidmann ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1220631949/34.

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29

DOMÍNGUEZ, RIVERA MARCOS. "STRUCTURAL AND ELECTRONIC COUPLING OF ORGANIC HETEROAROMATIC MOLECULES ON INORGANIC SURFACES OF OXIDES". Doctoral thesis, Università degli Studi di Trieste, 2017. http://hdl.handle.net/11368/2912861.

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Many novel technologies base their main capabilities on the interface between organic semiconductors and dielectric surfaces. Understanding and manipulating its behaviour becomes then an important task for their development, from production cost to efficiency and better employment qualities. In the present thesis, I dealt the issue of molecular ordering and electronic properties at the organodielectric interfaces of four donor heteroaromatic molecules regarding the rutile-TiO2 (110) surface in an ultra-high vacuum (UHV) environment, combining some of them with a carbon allotrope as acceptor. The interface electronic structure, morphology, conformation and chemical interaction of in situ grown thin film of metal-free tetraphenyl porphyrin (2H-TPP), have been investigated by means of STM and/or electron spectroscopies. The surface sensitivity and chemical selectivity of soft X-ray photoemission (XPS) and near-edge X-ray absorption (NEXAFS) allowed to monitor the chemical state upon absorption and the orientation of their molecular plane and peripheral substituents. Free base tetraphenyl porphyrins adsorb on the oxygen rows, where they can spontaneously capture additional hydrogen atoms at their iminic nitrogens (4H-TPP). Both species aggregate into a commensurate phase at saturation coverage (1M), and upon sample heating a self-metalation reaction sets in at about 100ºC. The Ti atoms are extracted from the substrate by dehydrogenation of pyrrolic nitrogen atoms from the macrocyle, where remain coordinated to two underlying oxygen atoms. The adsorption geometry and molecular arrangement remain invariable across the self-metalation up to 300ºC. The possible manifestation of metal exchange with reactive Ti atoms must be considered when designing porphyrin sensytized solar cells due to the critical self-metalation temperature, close to its normal operating temperature. Thermal stability up to 450ºC is also demonstrated, with a phase symmetry change from oblique-(2x4) to rect-(2x6), keeping chemical states of both the molecular tetrapyrrolic macrocycle and the substrate unchanged, revealing by NEXAFS that the driving mechanism is the rotation of the phenyl terminations towards the substrate (flattening) promoting the partial cyclodehydrogenation of the molecules, and preserving the coordination of the macrocycle central pocket to the oxygen atoms through the self-metalation and the flattening reactions. Porphyrins trapped at the TiO2(110) surface demonstrate a high thermal stability making it a promising system for implementation in photocatalysis applications and photovoltaic devices. Another heteroaromatic molecules have been also investigated: tert-butyl tetraphenyl porphyrin (2h-tbTPP), octaethyl porphyrin (2H-OEP) and phtalocyanine (2H-Pc). The experimental results point to the existence of an unaffected reaction by the substituents, the hydrogenation of the macrocycle as deposited, converting its aza- nitrogen atoms into pyrrolic- nitrogen atoms. The self-metalation (i.e. incorporation of a Ti ion extracted from the substrate) was also demonstrated by X-ray spectroscopy for the four compounds but is accomplished at different temperature, starting at room temperature for the 2H-Pc, and at 100ºC for 2H-TPP and being completed at 200ºC for 2H-tbTPP and 250ºC for 2H-OEP, opening the possibility of a self-metalation of free-metal compounds and trans-metalation for metalated compounds due to the lower temperatures needed depending on the peripheral substituents, during the experimentation and development of devices with this compounds.

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30

Yin, Chunfeng. "Regiospecific synthesis of chlorodihydroxybiphenyls and synthesis of 3,3'-bisaryl substituted BINOLs by combined directed ortho metalation (DoM) and Suzuki-Miyaura cross coupling". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63395.pdf.

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31

Nguyen, Quang. "Reinventing Aromatic Substitution: A Novel Look". TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1292.

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Electrophilic aromatic substitution (EAS) and directed ortho-metalation (DoM) involve the direct substitution of an arene hydrogen. A major drawback involving EAS is the necessity for harsh forcing conditions for the reaction to proceed. Catalysts such as Lewis acids FeBr3 and AICI3 for the introduction of halogens and acyl groups, respectively, are each highly toxic and corrosive. Textbook preparations of aryl iodides classicaly involved the use of iodine and nitric acid. This approach affords only modest yields and does not provide regiospecific substitution of most substituted aromatics because most contain ortho/para directors which afford mixtures of isomers. The novelty of our procedure for the synthesis of the iodinated aromatics is twofold in that regiospecific para-iodination is observed and hydrocarbon media are utilized. Hydrocarbon media are less hazardous and greener than media used for halogenations reported in literature. This procedure always yields derivatives regiospecifically substituted para to an electron donating substituent. Moreover, this method eliminates the need to use hazardous oxidative catalysts. DoM is a reaction regiospecifically substitute an arene hydrogen at the ortho position. The media used in DoM reactions are less hazardous than those required for a variety of EAS reactions. The only problem for this reaction is use of extremely strong bases, alkyllithium reagents, which are known to be air and water sensitive. However, the DoM reaction does eliminate the need to separate ortho/para isomer mixtures so that only a single product is generated. The metalation yields predominantly products regiospecifically substituted ortho-to the direcing metalating group (DMG). With our deficiency catalysis concept and subsequent purificaion methods, relatively pure ortho-lithiated intermediates have been prepared. The study of catalysts/promoters on the derivatization of these intermediates is anticipated to be extremely insightful. For this study, we have shown that highly selective, efficient ortho-lithiation can be achieved by deficiency catalysis utilizing n-BuLi as the only strong metalating base.

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32

Baldwin, Luke Adam. "Synthesis of Dehydrobenzoannulene-Based Covalent Organic Frameworks". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1491561788473597.

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33

Dunst, Cora. "Functionalization of arenes and heteroarenes by metalation with TMP-bases or metal insertion and synthesis of tetrasubstituted alkenyl sulfides via a Cu(I)-mediated carbometalation". Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-141952.

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34

Schwärzer, Kuno [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Highly regioselective addition of organozinc reagents to [1.1.1]propellane and Selective metalation of nitrogen containing heterocycles using 2,2,6,6-tetramethylpiperidyl bases / Kuno Schwärzer ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/1232176281/34.

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35

Peel, Andrew James. "Group 11 'ate bases : towards an understanding of solid- and solution-state structures". Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267910.

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Lithium bis(amido)cuprates are an important class of bimetallic base, which can chemo- and regioselectively metalate aromatic compounds, via directed ortho cupration (DoCu). This thesis begins with an introduction to aspects of the chemistry of organolithium compounds, group 11 organometallic compounds and their lithium 'ate complexes. Examples of such synergic bases are presented and the introduction is concluded with a discussion of lithium bis(amido)cuprate bases, which along with their silver congeners, are the subject of this dissertation. In general, syntheses involve the addition of a lithium amide to a group 11 salt, resulting in the formation of a lithium bis(amido)cuprate or argentate. Structurally focussed work commences with the use of new amide ligands to develop heteroleptic bis(amido)cuprate systems. The reaction of mixtures of lithium amides with CuBr provides a series of novel Lipshutz-type and Gilman cuprates. Interesting structural features are uncovered, which are rationalised in terms of altered steric demands in the newly introduced amide ligands in these systems. CuSCN and CuOCN are investigated as inexpensive and safer alternatives to CuCN in cuprate formation. In the solid state, a series of Lipshutz-type cuprates (TMP)2Cu(SCN)Li2(L) (L = Et2O, THF, THP) are revealed, whose molecular conformations are infuenced by the identity of the Lewis base. However, in benzene solution, in situ conversion of Lipshutz-type to Gilman cuprate is found to occur. Moving to the synthetic setting, derivatisation of chloropyridines is attempted and gives functionalised halopyridines in 51-71 % yield. CuOCN is found to behave quite differently when reacted in the same way as CuSCN, whereby X-ray crystallography reveals structures in which Cu-Li substitution is apparent. The unique reactivity of CuOCN is interpreted with the aid of multinuclear NMR spectroscopy. A new route to Lipshutz-type cuprates is explored by the synthesis of (TMP)2Cu(OCN)Li2(THF) from Gilman cuprate and LiOCN. This avoids Cu-Li substitution. Meanwhile, reaction of lithium N,N-diisopropylamide with CuOCN also avoids metal disorder, to give a novel lithium cuprate-lithium amide adduct. Further advances in our understanding of group 11 'ate complexes are made by introducing silver as a spectroscopically active nucleus in the lithium argentates (TMP)2AgLi and (TMP)2Ag(CN)Li2(THF). In the solid state, these parallel the structures known for Gilman cuprate (TMP)2CuLi and Lipshutz cuprate (TMP)2Cu(CN)Li2(THF), respectively. In solution, NMR spectroscopy reveals features consistent with retention of these structures. Lastly, the formation of mixed Cu-Li aggregates from combining TMPLi and TMPCu in aromatic solvent are investigated. Surprising reactivity is uncovered, in which the aromatic solvent is metalated and incorporated into mixed-metal aggregates. This thesis concludes with a summary of the findings and suggestions for future work, including how the findings presented herein may be transformed into practical improvements to cuprate systems. In particular, the possibility that Gilman cuprate may be activated towards the metalation of aromatic substrates by the addition of sub-stoichiometric or catalytic amounts of a lithium salt additive is explored.

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36

Michaux, Jérôme. "Méthodologies d'accès à des N-hydroxyphtalimides hautement substitués, vers de nouveaux catalyseurs d'oxydation aérobie". Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENV071/document.

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Dans un contexte industriel où les réactions d'oxydation sont réalisées dans des conditions qui ne satisfont pas toujours les principes de la chimie verte, notre groupe étudie des catalyseurs de structure N-hydroxyphtalimide (NHPI), pour l'oxydation aérobie de substrats organiques variés dans des conditions douces. Dans le but d'obtenir des catalyseurs plus actifs, deux familles d'analogues hautement substitués sur le noyau phtalimide ont été préparées, suivant deux nouvelles méthodologies de synthèse. La première consiste en la bis-ortho-métallation / silylation d'acides ortho-phtaliques non protégés, pour un accès très rapide à des analogues silylés du NHPI. Les premiers tests en catalyse d'oxydation aérobie montrent une influence intéressante des groupements silyles sur la stabilité de l'espèce active, via leur encombrement stérique, cela permettant une amélioration de l'activité catalytique. La seconde stratégie inclut une cyclotrimérisation [2+2+2] totalement intramoléculaire d'ène-diyne diesters, pour la construction d'un squelette bis-ortho-lactone pentacyclique innovant. Ces intermédiaires sont aisément transformés en 3,6-bis(2-hydroxyphényl)-4,5-diarylphtalimides, ces composés présentant une symétrie C2 et deux axes d'atropoisomérie. Le dédoublement des énantiomères a été effectué, dans la perspective d'obtenir des catalyseurs d'oxydation aérobie potentiellement énantiosélectifs
In the chemical industry, oxidation reactions are not often performed in green chemistry conditions. Our group has been studying N-hydroxyphthalimides (NHPI) catalysts for the aerobic oxidation of various organic substrates in mild conditions. In order to obtain more active catalysts, two families of analogs, showing high substitution on the phthalimide core, have been prepared, following two new synthetic methodologies. The first one consists of the bis-ortho-metalation / silylation of unprotected ortho-phthalic acids, for the efficient access to silylated analogs of NHPI. Preliminary tests in aerobic oxidation catalysis show an interesting influence of the bulkiness of the silyl groups towards the active species, because of increases in catalytic activities. The second strategy includes a totally intramolecular [2+2+2] cyclotrimerization of ene-diyne diesters, affording an innovative pentacyclic bis-ortho-lactone scaffold. These intermediates are easily converted to 3,6-bis(2-hydroxyphenyl)-4,5-diarylphthalimides, which present C2 symmetry and two atropoisomeric axis. The resolution of both enantiomers has been performed, in order to access aerobic oxidation catalysts with potent enantioselective activity

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37

Dunst, Cora [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Functionalization of arenes and heteroarenes by metalation with TMP-bases or metal insertion and synthesis of tetrasubstituted alkenyl sulfides via a Cu(I)-mediated carbometalation / Cora Dunst. Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2011. http://d-nb.info/1021307890/34.

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38

Chapell, Brian John. "Development of the di-tert-butylphosphinyl directed metalation group, application to the synthesis of aromatic phosphines, substituted ferrocenes and 7-substituted indoles ; Studies directed towards the total synthesis of biruloquinone". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60527.pdf.

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39

Haas, Diana [Verfasser], e 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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40

Weber, Alexander. "Supramolecular organisation, conformation and electronic properties of porphyrin molecules on metal substrates". Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/201.

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The investigation and control of molecular properties is currently a dynamic research field. Here I present molecular level studies of porphyrin molecules adsorbed on metal surfaces via Low Temperature Scanning Tunneling Microscopy/Spectroscopy (STM/STS), supported by complementary X-ray absorption experiments. Intermolecular and molecule-surface interactions of tetrapyrdil porphyrin (TPyP) on Ag(111) and Cu(111) were investigated. TPyP self-assembles on Ag(111) over a wide sample temperature range into large, highly-ordered 2D chiral domains. By contrast, adsorption of TPyP on the more reactive Cu(111) leads to temperature dependent assemblies, governed decisively by the strong substrate influence. The increased metal-surface interactions on Cu(111) are accompanied by a conformational distortion of the porphyrin macrocycle. The TPyP’s pyridil groups were coordinated with single iron molecules, forming metal-organic complexes. Furthermore, the porphyrin’s macrocycle was metalated by exposing a layer of well-ordered TPyP to an iron atom beam, demonstrating a novel approach towards the fabrication of metallo-tetraaryl porphyrins performed in two dimensions under ultrahigh vacuum conditions. This method was similarly used to form lanthanideporphyrinates by coordinating tetraphenyl porphyrin (TPP) macrocycles with cerium. The influence of the metal center on the porphyrins’ electronic structure was investigated via STS for TPP, TPyP,Fe−TPyP, Fe−TPP, Ce−TPP, and Co−TPP, whereby the inhomogenous electron density distribution associated with individual frontier orbitals were imaged via dI/dV mapping. The symmetry and form of the molecular orbitals could be directly correlated to the saddle-shaped conformational adaptation for the case of Co −TPP.

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41

Andersson, Hans. "Reaction between grignard reagents and heterocyclic N-oxides synthesis of substituted pyridines, piperidines and piperazines /". Doctoral thesis, Umeå : Department of Chemistry, Umeå University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-25619.

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42

Ziegler, Dorothée [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Metalation and functionalization of pyridones, naphthyridones and pyrones using TMP-bases and Generation of aryl and heteroaryl magnesium reagents in toluene by Br/Mg- and Cl/Mg-exchange / Dorothée Ziegler ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1174142901/34.

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43

Azzouz, Rabah. "Pyridinols protégés et leur utilisation en métallation. Synthèse d'indolizidines à partir de la pyridine : synthèse d'indolizidines à partir de la pyridine". Phd thesis, INSA de Rouen, 2008. http://tel.archives-ouvertes.fr/tel-00559656.

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Dans une première partie, la protection des phénols et des pyridinols a été étudiée. Une nouvelle méthode de tetrahydropyranylation a été développée via la réaction de Mitsunobu. Les pyridinols et des phénols ont ainsi été protégés sous forme d'acétal. Cette méthode est sélective d'un phénol vis-à-vis d'un alcool ou d'une amine. La métallation régiosélective des pyridinols 3- et 4- OTHP a été ensuite réalisée. La fonctionnalisation de ces composés, via des réactions successives de métallation et une hydrolyse acide, a permis la synthèse de pyridinols difonctionnalisés "one-pot". Dans le but d'étudier le pouvoir ortho-directeur du groupe O-THP lors de la réaction de métallation, des essais de déprotonations compétitives ont été réalisés avec un pyridinol protégé par un OMe ou une carbamate. Dans une seconde partie, nous avons étudié une synthèse courte et efficace de la (-)-lentiginosine et de ses épimères à partir de la 2-bromopyridine avec de bons rendements. Nous avons synthétisé la (-)-lentiginosine et deux de ses épimères avec de bons rendements. Au cours de cette synthèse, nous avons développé une nouvelle méthodologie de quaternarisation de pyridine via la réaction de Mitsunobu.

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44

Teulade-Fichou, Marie-Paule. "Vers une homologation de la reaction de michaelis-becker : avantage dans la preparation des phosphonates fonctionnels". Paris 6, 1986. http://www.theses.fr/1986PA066599.

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La methode de preparation utilise des carbanions phosphonates lithies (z)::(2)p(y)chrli. Elle realise l'introduction sur le phosphore et le carbone en position 1 de substituants non accessibles par le rearrangement thermique de michaelis-arbuzot. Ce procede est applique a des structures phosphoniques d'interet synthetique et biologique. Ce sont d'une part les alkylidene diphosphonates et d'autre part les formyl-1 phosphonate delta

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45

Azzouz, Rabah. "Pyridinols protégés et leur utilisation en métallation. Synthèse d'indolizidines à partir de la pyridine : synthèse d'indolizidines à partir de la pyridine". Electronic Thesis or Diss., Rouen, INSA, 2008. http://www.theses.fr/2008ISAM0004.

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Resumo:

Dans une première partie, la protection des phénols et des pyridinols a été étudiée. Une nouvelle méthode de tetrahydropyranylation a été développée via la réaction de Mitsunobu. Les pyridinols et des phénols ont ainsi été protégés sous forme d'acétal. Cette méthode est sélective d'un phénol vis-à-vis d'un alcool ou d'une amine. La métallation régiosélective des pyridinols 3- et 4- OTHP a été ensuite réalisée. La fonctionnalisation de ces composés, via des réactions successives de métallation et une hydrolyse acide, a permis la synthèse de pyridinols difonctionnalisés "one-pot". Dans le but d'étudier le pouvoir ortho-directeur du groupe O-THP lors de la réaction de métallation, des essais de déprotonations compétitives ont été réalisés avec un pyridinol protégé par un OMe ou une carbamate. Dans une seconde partie, nous avons étudié une synthèse courte et efficace de la (-)-lentiginosine et de ses épimères à partir de la 2-bromopyridine avec de bons rendements. Nous avons synthétisé la (-)-lentiginosine et deux de ses épimères avec de bons rendements. Au cours de cette synthèse, nous avons développé une nouvelle méthodologie de quaternarisation de pyridine via la réaction de Mitsunobu
We report that the tetrahydropyranylation of pyridinols and phenols, exhibiting especially very low nucleophilicities, can be achieved by means of Mitsunobu reaction with 2-hydroxy-tetrahydropyran. We studied the regioselective deprotonation of 3- an 4-(tetrahdropyran-2-yloxy)pyridines with n-butyllithium. Trapping the lithiated species with various electrophiles afforded functionalized pyridines in good yields. A one-pot procedure also allowed the double fuctionalization at C4 and C2 in the case of 3-O-THP-pyridine. The ortho-metallating ability of this group was examined in comparison with other well-known oxygen-based ortho-directing groups. A four-step synthesis of (-)-lentiginosine and its epimers is described starting from 2-bromopyridine. The key step consisted of a quaternarization of a fully unprotected pyridinium-polyol unit using Mitsunobu methodology. We have demonstrated that the Mitsunobu reaction is viable as a new methodology for the N-alkylation of pyridine and for the formation of bridgehead azabicyclic compounds from pyridine derivatives

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46

Nickel, Johannes [Verfasser], e Paul [Akademischer Betreuer] Knochel. "Lewis acid triggered regioselective metalation and deprotection of uracils, uridines and cytidines, preparation of pyrrolo[2,3-d]pyrimidines via an intramolecular copper-mediated carbomagnesation of ynamides and regioselective preparation of tetrasubstituted fluorobenzenes / Johannes Nickel ; Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1142787737/34.

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47

Mosrin, Marc. "Regio- and Chemoselective Metalations of N-Heterocycles". Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-102948.

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48

Boudet, Nadège. "Polyfunctionalizations of N-Heterocycles via Chemo- and Regioselective Metalations". Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-80314.

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49

Thomas, dit Dumont Laurence. "Contribution à la synthèse de la Streptonigrine. Synthèse de 4-phénylpyridines polyfonctionnelles par métallation et couplage croisé". Rouen, 1992. http://www.theses.fr/1992ROUES045.

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Ce travail décrit la synthèse de 4-phénylpyridines polyfonctionnelles nécessaires à la construction du squelette de la Streptonigrine. La stratégie de synthèse de ces dérivés utilise l'association de deux méthodes: la fonctionnalisation par métallation et le couplage biarylique catalysé par le palladium. Ce schéma de synthèse nous a conduit à étudier une méthode d'amination électrophile par voie carbanionique (préparation de 3-aminopyridines diverses), la métallation de pyridine-N-oxydes et le couplage pyridine-benzène. Dans une dernière partie nous avons realisé un couplage phénylpyridine-quinoléine

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50

Frischmuth, Annette Dorothee Sophie [Verfasser], e Paul [Akademischer Betreuer] Knochel. "New preparation of functionalized indoles and azaindoles via an intramolecular copper-mediated carbomagnesiation of ynamides,regioselective in situ trapping metalation of arenes and heteroarenes with TMPLi in the presence of metal salts and synthesis of SF5-substituted aromatics and heterocycles / Annette Dorothee Sophie Frischmuth. Betreuer: Paul Knochel". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1110749678/34.

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