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Development of Orthogonal Catalytic Click Processes That Forge Functional Linkages:Hackey, Meagan January 2024 (has links)
Thesis advisor: Amir H. Hoveyda / Chapter One: Development of a New Catalytic Click Reaction Involving Nitriles and Allenes (CuPDF)Catalytic click reactions, although small in number, have made a profound impact on chemistry research, including the fields of drug discovery, biological chemistry, and materials science. What is much needed are additional catalytic reactions that bring about the union of commonly occurring and robust functional groups, are mutually orthogonal to those that exist and offer a function other than connecting two fragments. We have developed a catalytic click process that connects a nitrile and a monosubstituted allene in the presence of commercially available B2(pin)2 and a readily accessible Cu(I) complex. The modification stage involves alkene isomerization by base and condensation with a hydrazine and both processes are performed in situ. The resulting linkages contain a robust diazaborinine that is fluorescent. We demonstrate that the click process, which we have named copper(I)-catalyzed phenoxydiazaborinine formation (CuPDF) is mutually orthogonal to copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) as well as sulfur-fluorine exchange (SuFEx). These click reactions can therefore be used for efficient synthesis of sequence-defined oligomers that may contain modifiable linkages and peptide-drug conjugates. For applications in aqueous media, we have also developed, copper(I)- and palladium-catalyzed quinoline formation (Cu/PdQNF). These latter processes generate fluorescent connectors as well.
Chapter Two: Development of a Catalytic Click Reaction Involving Ketones and Allenes (CuAKA)
We have developed another click reaction, this time bringing about the union of a ketone and, similar to CuPDF, a monosubstituted allene and B2(pin)2. We label this click reaction copper(I)-catalyzed allene–ketone addition or CuAKA. As a consequence of shared reactants, identifying catalysts that would allow CuAKA and CuPDF to be mutually orthogonal was at the center of our investigations. Our studies resulted in the identification of copper(I) complexes that can be used to perform a click reaction on a nitrile or a ketone. Furthermore, we found that mutual orthogonality can be achieved between CuAKA and CuAAC using an amino phosphine–Cu(I) catalyst. Computational and kinetics studies were performed that shed light on the origins of catalyst-controlled chemoselectivity. Importantly, similar to CuPDF, CuAKA can be performed in aqueous media.
Chapter Three: Preparation of Multi-drug Conjugates with Mutually Orthogonal Click Reactions
We show that with CuAAC, CuPDF and CuAKA, three mutually orthogonal click processes can be efficiently merged to assemble complex molecules efficiently with no protection/deprotection needed. With CuAKA, similar to CuAAC and CuPDF, being also orthogonal to SuFEx, a four-armed core molecule may be used in a similar fashion. A central finding in this part of study was the discovery that CuAKA, similar to CuAAC but unlike CuPDF, can be used to link molecules that contain acidic protons, such as phenol or a carboxylic acid moieties.
Chapter Four: Controlled Rupture of CuAKA-Generated Linkages
A distinct attribute of CuAKA is that it forms a linkage that is cleavable under mild aqueous oxidative conditions. We show that the tertiary hydroxy group accelerates the oxidation of the nearby C–B bond within the connector to generate a -hydroxy ketone that undergoes a retro-aldol reaction to effect rupture. We show that an aryl linker between the ketone and the carrier molecule, such a bile acid or a cell-penetrating peptide (CPP) may be used to achieve the steric and electronic parameters that are needed for optimal clicking and clipping rates. To demonstrate applicability, we used CuAKA was used for efficient linking of camptothecin, an anti-cancer agent with low selectivity, to a ketone attached to unprotected penetratin, a CPP. The ensuing release of the payload proceeded readily in a 68 mM aqueous solution of hydrogen peroxide at 37 °C with control experiments indicating that a proximal lysine residue accelerates the retro-aldol reaction. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
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Self-assembly of temperature-responsive protein–polymer bioconjugatesMoatsou, D., Li, J., Ranji, A., Pitto-Barry, Anaïs, Ntai, I., Jewett, M.C., O'Reilley, R.K. 2016 June 1917 (has links)
Yes / We report a simple temperature-responsive bioconjugate system comprising superfolder green fluorescent protein (sfGFP) decorated with poly[(oligo ethylene glycol) methyl ether methacrylate] (PEGMA) polymers. We used amber suppression to site-specifically incorporate the non-canonical azide-functional amino acid p-azidophenylalanine (pAzF) into sfGFP at different positions. The azide moiety on modified sfGFP was then coupled using copper-catalyzed “click” chemistry with the alkyne terminus of a PEGMA synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. The protein in the resulting bioconjugate was found to remain functionally active (i.e., fluorescent) after conjugation. Turbidity measurements revealed that the point of attachment of the polymer onto the protein scaffold has an impact on the thermoresponsive behavior of the resultant bioconjugate. Furthermore, small-angle X-ray scattering analysis showed the wrapping of the polymer around the protein in a temperature-dependent fashion. Our work demonstrates that standard genetic manipulation combined with an expanded genetic code provides an easy way to construct functional hybrid biomaterials where the location of the conjugation site on the protein plays an important role in determining material properties. We anticipate that our approach could be generalized for the synthesis of complex functional materials with precisely defined domain orientation, connectivity, and composition. / Engineering and Physical Sciences Research Council (EPSRC), University of Warwick, National Science Foundation (U.S.) (NSF), United States. Defense Advanced Research Projects Agency (DARPA), Seventh Framework Programme (European Commission) (FP7), European Research Council (ERC)
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Novel Approaches To The Synthesis of Clicked Block CopolymersFlack, Matthew Alexander 16 January 2011 (has links)
Block copolymers are widely used in both the academic and industrial communities due to their unique properties. With the development of living polymerization techniques, the synthesis of block copolymers with controlled molecular weights and unique architectures has reached an all time high. Here a novel approach to the synthesis of block copolymers, namely polystyrene-b-polyisoprene, using azide-alkyne click chemistry techniques is investigated. Both azido and alkyne-terminated polystyrene were synthesized using ATRP. Azido-terminated polystyrene was synthesized via a substitution reaction between NaN3 and bromo-terminated polystyrene. Alkyne-functionalized polystyrene was synthesized using propargyl 2-bromoisobutyrate as a functional initiator. ¹H NMR and SEC were used to analyze the degree of polymer functionalization. Anionic polymerization techniques were used to synthesize polyisoprene. Polyisoprenyl lithium was reacted with propylene oxide to obtain hydroxyl-terminated polyisoprene. Functionalization of ≥ 90% was demonstrated via flash column chromatography. The aforementioned hydroxyl-terminated polyisoprene was reacted with both 11-chloroundecanoyl bromide and 11-chloroundecanoyl chloride to synthesize halogen-terminated polyisoprene. As with polystyrene, a substitution reaction with NaN3 afforded azido-terminated polyisoprene. Alkyne-functionalized polystyrene was coupled with azido-terminated polyisoprene via click chemistry to create said block copolymers. The reactions were investigated using ¹H and ¹³C NMR, SEC, IR and in some cases TEM. The clicked block copolymers should provide precedent for the synthesis of supramolecular block copolymers. / Master of Science
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Mise au point de nouvelles méthodes de conjugaison oligonucléotide/sucre et développement d'un microsystème d'analyse des interactions lectine/sucre / Development of new methods for carbohydrate/oligonucleotide conjugation and of a microarray to study the lectin/carbohydrate interactionsPourceau, Gwladys 25 November 2010 (has links)
Les interactions entre les sucres et les lectines sont généralement l'étape clé dans de nombreux phénomènes biologiques et pathologiques. Malgré leu r importance cruciale, ces interactions sont paradoxalement caractérisées par des constantes d'affinité faibles et nécessite une multiprésentation des motifs saccharidiques pour être significatives. Cette augmentation est appelée "effet cluster". En outre, les techniques d'analyse actuellement utilisées en laboratoire nécessitent des quantités importantes de produits, ce qui est difficilement compatible avec les méthodes de synthèse actuelle. Pour pallier ces difficultés, une approche originale basée sur l'utilisation conjointe de glycooligonucléotide et de puces à ADN a été proposée. Les glycoconjugués basés sur des squelettes phosphodiesters et couplés à des séquences d'ADN ont été synthétisés en utilisant la chimie des oligonucléotides, couplée à la "click chemistry". La séquence d'ADN quant à elle a permis l'ancrage sur une puce à ADN et donc la mesure de leur affinité vis-à-vis de différentes lectines. Ce manuscrit rapporte le développement des nouvelles méthodologies de synthèse des glycooligonucléotides ainsi que la préparation de nombreux glycoconjugués originaux, dont l'affinité pour différentes lectines a été mesurée via l'utilisation de la puce à ADN. L'influence de plusieurs paramètres a été étudiée: le nombre de résidus, l'arrangement spatial, la lipophilie etc. Il s'avère que l'arrangement spatial semble être l'un des points les plus importants dans la mise au point d'un glycoconjugué. / The interactions between carbohydrates and lectins are generally the "key step" in many biological and pathological phenomena. Despite their importance, these interactions are paradoxically characterized by low affinity constants and requires multipresence of saccharide to be significant. This increase is called "cluster effect". In addition, the analysis techniques currently used in the laboratory requires large quantities of products, which is hardly compatible with the current methods of synthesis. To circumvent these difficulties, a original approach based on the combined use of glycooligonucleotides and DNA microarrays has been proposed. Glycoconjugates based on phosphodiester skeletons linked to DNA sequences have been synthesized using the chemistry of oligonucleotides, coupled with the "click chemistry". The DNA sequence has allowed the anchoring on a DNA chip and therefore the measurement of their affinity versus different lectins.This manuscript reports the development of new synthetic methodologies for the glycooligonucleotides synthesis and the preparation of many original glycoconjugates, whose affinity for various lectins was measured through the use of DNA microarray. The influence of several parameters was studied: the number of residues, the spatial arrangement, etc. lipophilicity. The spatial arrangement appears to be one of the most important parameters in the development of a glycoconjugate.
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Desenvolvimento de metaloclusters terpiridínicos automontados para aplicação em dispositivos moleculares / Develop ing self -assembled terpyridine metal o clusters for application in molecular devicesVelho, Rodrigo Garcia 25 March 2014 (has links)
Os Clusters de acetato de rutênio de fórmula geral [Ru3O(AcO)6L3]n proporcionam blocos de montagem interessantes para sistemas supramoleculares, exibindo características eletrocrômicas e redox reversível, cobrindo uma ampla faixa de potenciais em solventes aquosos e orgânicos. Nesta Tese, estas espécies foram combinadas com o ligante tridentado, 4\'-piridil-2,2\':6\',2\"-terpiridina (pytpy), produzindo complexos do tipo [Ru3O(AcO)6(pytpy)3]n e [Ru3O(AcO)6(py)2(pytpy)]n, que foram totalmente caracterizados em estado sólido e solução. Nestes complexos a terpiridina permanece disponível para ligar-se a íons metálicos como o Fe(II), gerando um complexo binuclear de baixo spin muito estável, do tipo {Fe[Ru3O(AcO)6(py)2(pytpy)]2}n. Este processo pode ser monitorado eletroquimicamente, partindo de íons Fe(III), que exibem uma baixa afinidade pela terpiridina central, e ciclando o potencial para gerar íons de Fe(II). Desta forma, pode-se executar um procedimento típico de click chemistry, que leva a uma estrutura estendida, Fe-cluster-pytpy na superfície do eletrodo. Este filme conserva a funcionalidade dos blocos de montagem, permitindo aplicações interessantes em dispositivos moleculares, tais como sensores e smart Windows. / Ruthenium acetate clusters of general formula [Ru3O(AcO)6L3]n provide interesting building blocks for assembling supramolecular systems, displaying reversible redox and electrochromic characteristics, over a wide range of potentials in aqueous and organic solvents. In this thesis, such species has been combined with the tritopic, 4\'-pyridil-2,2\':6\',2\"-terpiridine (pytpy) ligand, yielding complexes of the type [Ru3O(AcO)6(pytpy)3]n and [Ru3O(AcO)6(py)2(pytpy)]n, which have been fully characterized in solid state and solution. In these complexes, the terpyridine moiety remains available for binding metals ions, such as Fe(II), generating very stable, low spin binuclear complexes, of the type n. This process can be monitored electrochemically, starting from Fe(III) ions, which exhibits a much lower affinity for the terpyridine center, and cycling the potentials in order to generate Fe(II) ions. In this way, one can start a click chemistry, ending up with an extended structure of Fe-cluster-pytpy film at the electrode surface. This film preserves the functionality of the building block complexes, a llowing many possible applications in molecular devices, such as sensors and smart windows.
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Planejamento e síntese de tuberculostáticos potenciais com base na estrutura de maltosiltransferase (GlgE) de Mycobacterium tuberculosis / Design and synthesis of potential tuberculostatics based in maltosyltransferase (GlgE) of Mycobacterium tuberculosis.Natanael Dante Segretti 21 March 2017 (has links)
A tuberculose (TB) é uma doença infectocontagiosa causada principalmente pelo Mycobacterium tuberculosis (Mtb). A TB era uma doença considerada em vias de extinção, porém sua incidência voltou a aumentar devido a diversos fatores, como o fluxo migratório dos chamados \"Países Reservatórios\" e a pandemia da AIDS. Em 2013, a OMS estimou 9 milhões de novos casos de TB e 1,5 milhões de mortes. A multirresistência aos quimioterápicos disponíveis justifica a procura por novos tuberculostáticos. Face ao exposto, o trabalho objetivou a síntese de potenciais inibidores da maltosiltransferase (GlgE), um novo e promissor alvo contra o Mtb, utilizando Planejamento com base na Estrutura do Alvo Molecular -- Structure-Based Drug Design (SBDD). A comparação das simulações de dinâmica molecular do sistema apo da GlgE e em complexo com a maltose-1-fosfato (M1P) mostrou as mudanças estruturais, em nível atômico, decorrentes da ligação com seu substrato. Levando em consideração estes dados, as simulações de docking dos potenciais inibidores revelaram que análogos glicosídicos e maltosídicos triazólicos ligados a grupos aromáticos substituídos possuem melhores perfis de interação com o sítio ativo da GlgE e, por essa razão, foram escolhidos para síntese. Assim, sintetizaram-se análogos glicosídicos e maltosídicos através da click chemistry, obtendo-se rendimentos variados. Posteriormente, realizaram-se ensaios enzimáticos e microbiológicos no Institute for Tuberculosis Research (ITR), University of Illinois at Chicago, USA. Apesar de os ensaios enzimáticos estarem em andamento, os compostos ensaiados apresentaram atividades que variaram de moderada a fraca, frente à cepa H37Rv. Dois compostos glicosídicos exibiram valores de Concentração Inibitória Mínima (CIM) inferiores a 60 µM, sem efeito citotóxico em células VERO em concentrações superiores a 250 µM. Tais resultados indicam que o análogo glicosídico triazólico aromático, como o NDS 112, pode ser utilizado como protótipo interessante para o planejamento de novas séries de compostos capazes de atuar como tuberculostáticos / Tuberculosis (TB) is an contagious infectious disease mainly caused by Mycobacterium tuberculosis (Mtb). TB was a disease considered in extinction, but its incidence has risen again due to several factors, such as the migration from \"Reservatoir Countries\" and AIDS pandemic. In 2013, WHO estimated 9 million new TB cases and 1.5 million deaths. Multidrug resistance to drugs available in chemotherapy validates the search for new TB drugs. In this context, this work aimed to the design and synthesis of potential inhibitors of maltosyltransferase (GlgE), a new and promissor target against Mtb using Structure-Based Drug Design. Comparison between molecular dynamic simulations of GlgE apo system and in complex with maltose-1-phosphate (M1P) showed important structural changes at molecular level due to substrate binding. Considering these data, docking simulations of potential inhibitors revealed that glucoside and maltoside triazoles analogues bound to substituted aromatic groups have better interaction profiles with the GlgE active site and for this reason they were chosen for synthesis. Thus, glucoside and maltoside triazole analogues were synthetized through click chemistry with different yields. Then, enzymatic and microbiological assays were performed at Institute for Tuberculosis Research (ITR), University of Illinois at Chicago, USA. Although the enzymatic assays are ongoing, componds were tested against H37Rv strains and they have shown activity ranging from moderate to weak. Two compounds presented Minimal Inhibitory Concentration (MIC) values below 60 µM, without cytotoxic effect in VERO cells in concentrations higher than 250 µM. These results indicate that glucosidic aromatic triazoles analogues, such as NDS 112, can be used as a prototype for design new series of compounds capable of acting as antituberculosis agents
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Síntese e funcionalização de compostos organoenxofre: sulfóxidos, sulfetos e N-sulfinil iminas / Synthesis and functionalization of organosulfur compounds: sulfoxides, sulfides and N-sulfinyl iminesSouza, Frederico Bernardes de 22 September 2017 (has links)
Neste trabalho promovemos a síntese de sulfóxidos vinílicos ?-substituídos através da reação de acoplamento cruzado de Suzuki-Miyaura. Também foi feita a síntese de sulfóxidos enínicos inéditos, pela adição do nucleófilo no carbono β-sulfóxido. Esses compostos eram passíveis de serem submetidos a reação de rearranjo de Pummerer aditivo e assim gerarem uma pequena biblioteca de compostos α-tioaldeídos. Um desses aldeídos sintetizados foi empregado na reação de formação de uma imina propargílica, com consequente reação de CuAAC formando iminas triazólicas. Outras iminas arílicas foram sintetizadas, passando por uma etapa de redução, com intuito de se obter a amina livre, para que fosse feita a reação de ciclização com auxílio de um agente eletrofílico. Outra classe de composto organoenxofre foi sintetizada, as N-sulfinil imina, que após a reação de acoplamento cruzado de Sonogashira, com consequente remoção de um grupo protetor e a formação do anel heterocíclico, foram obtidos compostos triazólicos N-sulfinil imínicos. / In this work we promote the synthesis of α-substituted vinylic sulfoxides through the Suzuki-Miyaura cross coupling reaction. Also the synthesis of unpublished enynic sulfoxides was made, by the addition of the nucleophile in the β-sulfoxide carbon. These compounds were susceptible to additive Pummerer rearragement reaction and thus generated a small library of compounds. One of these aldehydes synthesized was used in the formation reaction of a propargyl imine, with consequent CuAAC reaction, forming triazol imines. Other aryl imines were synthesized, undergoing a reduction step, in order to obtain the free amine, so that the cyclization reaction was carried out with the aid of an electrophilic agent. Another class of organosulfur compound was synthesized, the N-sulfinyl imine, which after the Sonogashira cross-coupling reaction, with consequent removal of a protecting group and formation of the heterocyclic ring, N-sulfinyl imine triazolic compounds were obtained.
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Planejamento e síntese de tuberculostáticos potenciais com base na estrutura de maltosiltransferase (GlgE) de Mycobacterium tuberculosis / Design and synthesis of potential tuberculostatics based in maltosyltransferase (GlgE) of Mycobacterium tuberculosis.Segretti, Natanael Dante 21 March 2017 (has links)
A tuberculose (TB) é uma doença infectocontagiosa causada principalmente pelo Mycobacterium tuberculosis (Mtb). A TB era uma doença considerada em vias de extinção, porém sua incidência voltou a aumentar devido a diversos fatores, como o fluxo migratório dos chamados \"Países Reservatórios\" e a pandemia da AIDS. Em 2013, a OMS estimou 9 milhões de novos casos de TB e 1,5 milhões de mortes. A multirresistência aos quimioterápicos disponíveis justifica a procura por novos tuberculostáticos. Face ao exposto, o trabalho objetivou a síntese de potenciais inibidores da maltosiltransferase (GlgE), um novo e promissor alvo contra o Mtb, utilizando Planejamento com base na Estrutura do Alvo Molecular -- Structure-Based Drug Design (SBDD). A comparação das simulações de dinâmica molecular do sistema apo da GlgE e em complexo com a maltose-1-fosfato (M1P) mostrou as mudanças estruturais, em nível atômico, decorrentes da ligação com seu substrato. Levando em consideração estes dados, as simulações de docking dos potenciais inibidores revelaram que análogos glicosídicos e maltosídicos triazólicos ligados a grupos aromáticos substituídos possuem melhores perfis de interação com o sítio ativo da GlgE e, por essa razão, foram escolhidos para síntese. Assim, sintetizaram-se análogos glicosídicos e maltosídicos através da click chemistry, obtendo-se rendimentos variados. Posteriormente, realizaram-se ensaios enzimáticos e microbiológicos no Institute for Tuberculosis Research (ITR), University of Illinois at Chicago, USA. Apesar de os ensaios enzimáticos estarem em andamento, os compostos ensaiados apresentaram atividades que variaram de moderada a fraca, frente à cepa H37Rv. Dois compostos glicosídicos exibiram valores de Concentração Inibitória Mínima (CIM) inferiores a 60 µM, sem efeito citotóxico em células VERO em concentrações superiores a 250 µM. Tais resultados indicam que o análogo glicosídico triazólico aromático, como o NDS 112, pode ser utilizado como protótipo interessante para o planejamento de novas séries de compostos capazes de atuar como tuberculostáticos / Tuberculosis (TB) is an contagious infectious disease mainly caused by Mycobacterium tuberculosis (Mtb). TB was a disease considered in extinction, but its incidence has risen again due to several factors, such as the migration from \"Reservatoir Countries\" and AIDS pandemic. In 2013, WHO estimated 9 million new TB cases and 1.5 million deaths. Multidrug resistance to drugs available in chemotherapy validates the search for new TB drugs. In this context, this work aimed to the design and synthesis of potential inhibitors of maltosyltransferase (GlgE), a new and promissor target against Mtb using Structure-Based Drug Design. Comparison between molecular dynamic simulations of GlgE apo system and in complex with maltose-1-phosphate (M1P) showed important structural changes at molecular level due to substrate binding. Considering these data, docking simulations of potential inhibitors revealed that glucoside and maltoside triazoles analogues bound to substituted aromatic groups have better interaction profiles with the GlgE active site and for this reason they were chosen for synthesis. Thus, glucoside and maltoside triazole analogues were synthetized through click chemistry with different yields. Then, enzymatic and microbiological assays were performed at Institute for Tuberculosis Research (ITR), University of Illinois at Chicago, USA. Although the enzymatic assays are ongoing, componds were tested against H37Rv strains and they have shown activity ranging from moderate to weak. Two compounds presented Minimal Inhibitory Concentration (MIC) values below 60 µM, without cytotoxic effect in VERO cells in concentrations higher than 250 µM. These results indicate that glucosidic aromatic triazoles analogues, such as NDS 112, can be used as a prototype for design new series of compounds capable of acting as antituberculosis agents
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Desenvolvimento de metaloclusters terpiridínicos automontados para aplicação em dispositivos moleculares / Develop ing self -assembled terpyridine metal o clusters for application in molecular devicesRodrigo Garcia Velho 25 March 2014 (has links)
Os Clusters de acetato de rutênio de fórmula geral [Ru3O(AcO)6L3]n proporcionam blocos de montagem interessantes para sistemas supramoleculares, exibindo características eletrocrômicas e redox reversível, cobrindo uma ampla faixa de potenciais em solventes aquosos e orgânicos. Nesta Tese, estas espécies foram combinadas com o ligante tridentado, 4\'-piridil-2,2\':6\',2\"-terpiridina (pytpy), produzindo complexos do tipo [Ru3O(AcO)6(pytpy)3]n e [Ru3O(AcO)6(py)2(pytpy)]n, que foram totalmente caracterizados em estado sólido e solução. Nestes complexos a terpiridina permanece disponível para ligar-se a íons metálicos como o Fe(II), gerando um complexo binuclear de baixo spin muito estável, do tipo {Fe[Ru3O(AcO)6(py)2(pytpy)]2}n. Este processo pode ser monitorado eletroquimicamente, partindo de íons Fe(III), que exibem uma baixa afinidade pela terpiridina central, e ciclando o potencial para gerar íons de Fe(II). Desta forma, pode-se executar um procedimento típico de click chemistry, que leva a uma estrutura estendida, Fe-cluster-pytpy na superfície do eletrodo. Este filme conserva a funcionalidade dos blocos de montagem, permitindo aplicações interessantes em dispositivos moleculares, tais como sensores e smart Windows. / Ruthenium acetate clusters of general formula [Ru3O(AcO)6L3]n provide interesting building blocks for assembling supramolecular systems, displaying reversible redox and electrochromic characteristics, over a wide range of potentials in aqueous and organic solvents. In this thesis, such species has been combined with the tritopic, 4\'-pyridil-2,2\':6\',2\"-terpiridine (pytpy) ligand, yielding complexes of the type [Ru3O(AcO)6(pytpy)3]n and [Ru3O(AcO)6(py)2(pytpy)]n, which have been fully characterized in solid state and solution. In these complexes, the terpyridine moiety remains available for binding metals ions, such as Fe(II), generating very stable, low spin binuclear complexes, of the type n. This process can be monitored electrochemically, starting from Fe(III) ions, which exhibits a much lower affinity for the terpyridine center, and cycling the potentials in order to generate Fe(II) ions. In this way, one can start a click chemistry, ending up with an extended structure of Fe-cluster-pytpy film at the electrode surface. This film preserves the functionality of the building block complexes, a llowing many possible applications in molecular devices, such as sensors and smart windows.
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Síntese e funcionalização de compostos organoenxofre: sulfóxidos, sulfetos e N-sulfinil iminas / Synthesis and functionalization of organosulfur compounds: sulfoxides, sulfides and N-sulfinyl iminesFrederico Bernardes de Souza 22 September 2017 (has links)
Neste trabalho promovemos a síntese de sulfóxidos vinílicos ?-substituídos através da reação de acoplamento cruzado de Suzuki-Miyaura. Também foi feita a síntese de sulfóxidos enínicos inéditos, pela adição do nucleófilo no carbono β-sulfóxido. Esses compostos eram passíveis de serem submetidos a reação de rearranjo de Pummerer aditivo e assim gerarem uma pequena biblioteca de compostos α-tioaldeídos. Um desses aldeídos sintetizados foi empregado na reação de formação de uma imina propargílica, com consequente reação de CuAAC formando iminas triazólicas. Outras iminas arílicas foram sintetizadas, passando por uma etapa de redução, com intuito de se obter a amina livre, para que fosse feita a reação de ciclização com auxílio de um agente eletrofílico. Outra classe de composto organoenxofre foi sintetizada, as N-sulfinil imina, que após a reação de acoplamento cruzado de Sonogashira, com consequente remoção de um grupo protetor e a formação do anel heterocíclico, foram obtidos compostos triazólicos N-sulfinil imínicos. / In this work we promote the synthesis of α-substituted vinylic sulfoxides through the Suzuki-Miyaura cross coupling reaction. Also the synthesis of unpublished enynic sulfoxides was made, by the addition of the nucleophile in the β-sulfoxide carbon. These compounds were susceptible to additive Pummerer rearragement reaction and thus generated a small library of compounds. One of these aldehydes synthesized was used in the formation reaction of a propargyl imine, with consequent CuAAC reaction, forming triazol imines. Other aryl imines were synthesized, undergoing a reduction step, in order to obtain the free amine, so that the cyclization reaction was carried out with the aid of an electrophilic agent. Another class of organosulfur compound was synthesized, the N-sulfinyl imine, which after the Sonogashira cross-coupling reaction, with consequent removal of a protecting group and formation of the heterocyclic ring, N-sulfinyl imine triazolic compounds were obtained.
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