A direct and highly efficient synthesis has been developed for telmisartan, the active ingredient in the widely prescribed antihypertensive drug Micardis®. This approach brings together two functionalized benzimidazoles using a high-yielding Suzuki reaction that can be catalyzed by a homogeneous palladium source or palladium on a solid support. The ability to perform the cross-coupling reaction was facilitated by the regio-controlled preparation of a 2-bromo-1-methylbenzimidazole precursor. The method developed is the first reported selective bromination at the 2-position of a benzimidazole and produces the first major precursor in high yield (93%). The second precursor, potassium (4-methyl-2-propylbenzimidazol-6-yl) trifluoroborate, was prepared from commercially available 4-bromo-2-methyl-6-nitroaniline. An optimized preparation is described that provides a direct three-step process to prepare the benzimidazole and install the borate; this synthetic sequence yields the second precursor with a 90% yield and no isolated intermediates. The two prepared precursors were combined with a third, commercially available methyl-4’-(bromomethyl)-[1,1’-biphenyl]-2-carboxylate, utilizing a short sequence of high yielding reactions to produce the telmisartan with an 83% yield from these advanced intermediates. This new convergent approach provides the active drug ingredient with an overall yield of 74% while circumventing many issues associated with the previously reported processes. Additionally, a flow-based synthesis of telmisartan was achieved with no intermediate purifications or solvent exchanges. The continuous process utilizes a tubular reactor system coupled with a plug flow cartridge, ultimately delivering telmisartan in an 86% isolated yield.

Thesis advisor: Lawrence T. Scott / The Scott lab is interested in the functionalization of corannulene as a building block for large polycyclic aromatic hydrocarbons and carbon nanotube end-cap precursors. Toward that end, a new approach to the direct five-fold borylation of corannulene with iridium (I) catalysts via C-H activation has been explored. It has been discovered that the addition of catalytic amounts of base to the reaction mixture promotes the formation of symmetrical penta-borylated corannulene in a good yield on a sizable scale. All byproducts can be easily removed with iterative methanol washes. The present work also provides proof of the reversibility of the direct borylation reaction under the conditions used. Furthermore, modified Suzuki-Miyaura conditions have been employed to synthesize pentakis(2,6-dichlorophenyl)corannulene, a precursor for a [5,5] carbon nanotube end-cap. The reported reactions provide good yields and are scalable. / Thesis (MS) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Catalysis is one of the pillars of the chemical industry. While the use of catalyst is typically recognized in the automobile industry, their impact is more widespread as; catalysts are used in the synthesis of 80% of the US commercial chemicals. Despite the improved selectivity provided by catalyst, process inefficiencies still threaten the sustainability of a number of synthesis methods, especially in the pharmaceutical industry. Recyclable solid supported catalysts offer a unique opportunity to address these inefficiencies. Such systems coupled with continuous synthesis techniques, have the potential to significantly reduce the waste to desired product ratio (E-factor) of the production techniques. This research focuses developing sustainable processes to synthesize organic molecules by using continuous synthesis methods. In doing so, solid supported metal catalyst systems were identified, developed, and implemented to assist in the formation of carbon-carbon bonds. Newly developed systems, which utilized metal nanoparticles, showed reactivity and recyclability, comparable to commercially available catalyst. Nanoparticles are emerging as useful materials in a wide variety of applications including catalysis. These applications include pharmaceutical processes by which complex and useful organic molecules can be prepared. As such, an effective and scalable synthesis method is required for the preparation of nanoparticle catalysts with significant control of the particle size, uniform dispersion, and even distribution of nanoparticles when deposited on the surface of a solid support. This project describes the production of palladium nanoparticles on a variety of solid supports and the evaluation of these nanoparticles for cross coupling reactions. This report highlights novel synthesis techniques used in the formation of palladium nanoparticles using traditional batch reactions. The procedures developed for the batch formation of palladium nanoparticles on different solid supports, such as graphene and carbon nanotubes, are initially described. The major drawbacks of these methods are discussed, including limited scalability, variation of nanoparticle characteristics from batch to batch, and technical challenges associated with efficient heating of samples. Furthermore, the necessary conditions and critical parameters to convert the batch synthesis of solid supported palladium nanoparticles to a continuous flow process are presented. This strategy not only alleviates the challenges associated with the robust preparation of the material and the limitations of scalability, but also showcases a new continuous reactor capable of efficient and direct heating of the reaction mixture under microwave irradiation. This strategy was further used in the synthesis of zinc oxide nanoparticles. Particles synthesized using this strategy as well as traditional synthesis methods, were evaluated in the context industrially relevant applications.

Este trabalho tem como principais objetivos: desenvolver procedimentos sintéticos e novos materiais poliméricos que apresentem boa condutividade elétrica, estudar o comportamento eletro-óptico dos polímeros obtidos, desenvolver procedimentos para a construção de dispositivos eletroluminescentes, caracterizá-los e correlacionar as características eletro-ópticas observadas com a constituição da camada ativa polimérica. Foram realizadas diversas sínteses objetivando a preparação de polifluorenos com diferentes estruturas químicas a partir de monômeros difuncionais aromáticos boronados e bromados, utilizando uma mesma rota de acoplamento de Suzuki. Assim, foram preparados três polímeros, poli[2,7-(9,9-dioctilfluoreno)] (PF, polifluoreno), poli[1,4-fenileno-alt-2,7- (9,9-dioctilfluoreno)] [PFP, poli(fluoreno-fenileno)] e poli[(1,4-fenileno-2-flúor)-alt-2,7-(9,9- dioctilfluoreno)] [PFPF, poli(fluoreno-fenileno)fluorado]. Para obtenção destes polifluorenos com bom rendimento e com pureza adequada para a preparação de dispositivos poliméricos eletroluminescentes, foi necessário testar diversas condições de reação, até a otimização de um procedimento sintético robusto. Os polifluorenos preparados foram exaustivamente purificados por extração e solubilização-precipitação. Todos os polifluorenos tiveram a sua estrutura e composição químicas caracterizadas e confirmadas pelas técnicas de espectroscopia no infravermelho (FTIR), espectroscopia de ressonância magnética nuclear de hidrogênio (¹HNMR) e espectroscopia de energia dispersiva de raios-X (EDX). As massas molares médias e a polidispersão foram determinadas por cromatografia de permeação em gel (GPC). Soluções em clorofórmio dos polifluorenos foram analisadas por espectroscopias de absorção e emissão no UV-Vis. Estes resultados nos forneceram informações importantes quanto às propriedades de fotoluminescência dos polifluorenos obtidos. Até o momento, sabe-se que todos os três polímeros emitem cor azul e dentre as três estruturas estudadas, o PFPF apresentou maior intensidade de fluorescência. Para a fabricação dos P-OLEDs (Diodos Orgânico-Polimérico Emissor de Luz) foram feitas soluções de clorofórmio em concentrações de 1% dos três tipos de polímeros. Também foi estudada a influência dos compostos ETL (electron transport layer) (Alq3 ou butyl-PBD) com concentrações de 0,5%. Quando aplicada uma tensão no dispositivo, o PFPF apresentou menor tensão de operação entre os polímeros estudados. A partir das curvas de tensão vs. corrente, verificou-se que a adição do butyl-PBD nos três tipos de polímeros diminui a tensão de limiar em comparação com os dispositivos sem composto ETL. Os comprimentos de onda de eletroluminescência dos dispositivos polarizados permaneceram constante mesmo com a adição dos dois compostos ETL (Alq3 ou butyl-PBD). / This work has as main objectives: develop synthetic procedures and new electroluminescent polymeric materials that have good electrical conductivity, study the behavior of polymer systems thus obtained, and develop procedures for the construction of electroluminescent devices, characterize them and correlate the photo- electrical behavior with the features of the constitutive active polymeric layer Several syntheses were performed aiming at preparing polyfluorenes with different structures from boronated and brominated difunctional aromatic monomers using a Suzuki coupling route. So far, three polymers were prepared, poly[2,7-(9,9-dioctylfluorene)] (PF, polyfluorene), poly[1,4-phenylene-alt-2,7-(9,9-dioctylfluorene)] [PFP, poly(fluorenephenylene)] and poly[1,4-phenylene-2-fluoro)-alt-2,7-(9,9-dioctylfluorene)] [PFPF, fluorinated poly(fluorene-phenylene)]. To obtain these polyfluorenos with good yield and purity suitable for preparing polymeric electroluminescent devices, it was necessary to test various reaction conditions and to optimize a robust synthetic procedure. The polyfluorenes prepared were thoroughly purified by extraction and solubilization-precipitation. All polyfluorenes have had their structures and chemical composition characterized and confirmed by infrared spectroscopy (FTIR), and hydrogen and carbon-13 nuclear magnetic resonance spectroscopy (¹HNMR and 13CNMR). The average molar masses and polydispersity were determined by gel permeation chromatography (GPC). Polyfluorenes in chloroform solutions were analyzed by the UV-Vis absorption and emission spectroscopy. These results provided us with important information regarding the photoluminescence properties of polyfluorenes thus obtained. Until now, it is known that all three polymers emit in the blue region and among the three structures, the PFPF has the highest fluorescence intensity. The construction of PLEDs was carried out from the chloroform solutions at concentrations of 1% for each of the all three types of polymers. The influence of an ETL (electron transport layer) compound (Alq3, PBD) was also studied, and its concentration was kept constant at 5% in the polymer solution. Tests of the devices under applied voltage have shown a higher stability for PFPF among all. From the voltage vs. current curves, it was possible to observe that the addition of PBD decreased the threshold voltage for the devices prepared from the three types of polymers. The wavelength of electroluminescence remained constant despite the addition of the ETL compound (Alq3 or butyl-PBD).

Este trabalho tem como principais objetivos: desenvolver procedimentos sintéticos e novos materiais poliméricos que apresentem boa condutividade elétrica, estudar o comportamento eletro-óptico dos polímeros obtidos, desenvolver procedimentos para a construção de dispositivos eletroluminescentes, caracterizá-los e correlacionar as características eletro-ópticas observadas com a constituição da camada ativa polimérica. Foram realizadas diversas sínteses objetivando a preparação de polifluorenos com diferentes estruturas químicas a partir de monômeros difuncionais aromáticos boronados e bromados, utilizando uma mesma rota de acoplamento de Suzuki. Assim, foram preparados três polímeros, poli[2,7-(9,9-dioctilfluoreno)] (PF, polifluoreno), poli[1,4-fenileno-alt-2,7- (9,9-dioctilfluoreno)] [PFP, poli(fluoreno-fenileno)] e poli[(1,4-fenileno-2-flúor)-alt-2,7-(9,9- dioctilfluoreno)] [PFPF, poli(fluoreno-fenileno)fluorado]. Para obtenção destes polifluorenos com bom rendimento e com pureza adequada para a preparação de dispositivos poliméricos eletroluminescentes, foi necessário testar diversas condições de reação, até a otimização de um procedimento sintético robusto. Os polifluorenos preparados foram exaustivamente purificados por extração e solubilização-precipitação. Todos os polifluorenos tiveram a sua estrutura e composição químicas caracterizadas e confirmadas pelas técnicas de espectroscopia no infravermelho (FTIR), espectroscopia de ressonância magnética nuclear de hidrogênio (¹HNMR) e espectroscopia de energia dispersiva de raios-X (EDX). As massas molares médias e a polidispersão foram determinadas por cromatografia de permeação em gel (GPC). Soluções em clorofórmio dos polifluorenos foram analisadas por espectroscopias de absorção e emissão no UV-Vis. Estes resultados nos forneceram informações importantes quanto às propriedades de fotoluminescência dos polifluorenos obtidos. Até o momento, sabe-se que todos os três polímeros emitem cor azul e dentre as três estruturas estudadas, o PFPF apresentou maior intensidade de fluorescência. Para a fabricação dos P-OLEDs (Diodos Orgânico-Polimérico Emissor de Luz) foram feitas soluções de clorofórmio em concentrações de 1% dos três tipos de polímeros. Também foi estudada a influência dos compostos ETL (electron transport layer) (Alq3 ou butyl-PBD) com concentrações de 0,5%. Quando aplicada uma tensão no dispositivo, o PFPF apresentou menor tensão de operação entre os polímeros estudados. A partir das curvas de tensão vs. corrente, verificou-se que a adição do butyl-PBD nos três tipos de polímeros diminui a tensão de limiar em comparação com os dispositivos sem composto ETL. Os comprimentos de onda de eletroluminescência dos dispositivos polarizados permaneceram constante mesmo com a adição dos dois compostos ETL (Alq3 ou butyl-PBD). / This work has as main objectives: develop synthetic procedures and new electroluminescent polymeric materials that have good electrical conductivity, study the behavior of polymer systems thus obtained, and develop procedures for the construction of electroluminescent devices, characterize them and correlate the photo- electrical behavior with the features of the constitutive active polymeric layer Several syntheses were performed aiming at preparing polyfluorenes with different structures from boronated and brominated difunctional aromatic monomers using a Suzuki coupling route. So far, three polymers were prepared, poly[2,7-(9,9-dioctylfluorene)] (PF, polyfluorene), poly[1,4-phenylene-alt-2,7-(9,9-dioctylfluorene)] [PFP, poly(fluorenephenylene)] and poly[1,4-phenylene-2-fluoro)-alt-2,7-(9,9-dioctylfluorene)] [PFPF, fluorinated poly(fluorene-phenylene)]. To obtain these polyfluorenos with good yield and purity suitable for preparing polymeric electroluminescent devices, it was necessary to test various reaction conditions and to optimize a robust synthetic procedure. The polyfluorenes prepared were thoroughly purified by extraction and solubilization-precipitation. All polyfluorenes have had their structures and chemical composition characterized and confirmed by infrared spectroscopy (FTIR), and hydrogen and carbon-13 nuclear magnetic resonance spectroscopy (¹HNMR and 13CNMR). The average molar masses and polydispersity were determined by gel permeation chromatography (GPC). Polyfluorenes in chloroform solutions were analyzed by the UV-Vis absorption and emission spectroscopy. These results provided us with important information regarding the photoluminescence properties of polyfluorenes thus obtained. Until now, it is known that all three polymers emit in the blue region and among the three structures, the PFPF has the highest fluorescence intensity. The construction of PLEDs was carried out from the chloroform solutions at concentrations of 1% for each of the all three types of polymers. The influence of an ETL (electron transport layer) compound (Alq3, PBD) was also studied, and its concentration was kept constant at 5% in the polymer solution. Tests of the devices under applied voltage have shown a higher stability for PFPF among all. From the voltage vs. current curves, it was possible to observe that the addition of PBD decreased the threshold voltage for the devices prepared from the three types of polymers. The wavelength of electroluminescence remained constant despite the addition of the ETL compound (Alq3 or butyl-PBD).

[pt] A reação de acoplamento C-C de Suzuki, desde a sua descoberta, sempre atraiu o interesse de diversos pesquisadores e encontrou aplicação em diversos campos tanto na academia como na indústria. Movidos pelos problemas ambientais que tanto preocupam nossa sociedade e pelos princípios da química verde, criados para guiar os químicos na direção de uma ciência sustentável, pesquisadores tem buscado criar catalisadores eficientes para essa reação, que consigam uma alta seletividade em condições reacionais brandas. O desenvolvimento de catalisadores heterogêneos é motivado pela sua fácil remoção do meio reacional e seu possível reuso para um elevado número de reações. Uma abordagem para criação desses catalisadores é a ancoragem de íons metálicos ou de nanopartículas (Nps) metálicas em suportes que facilitem seu manuseio, remoção e reuso. Neste trabalho foram sintetizadas nanopartículas de paládio (Nps Pd) estabilizadas por carboximetilcelulose (CMC), em cuja síntese foi utilizado o ácido L-ascórbico (AA) como agente redutor. Essas Nps foram caracterizadas por UV-VIS, FT-IR-ATR, DLS, potencial zeta, MEV e EDS. A reação de redução do 4-nitrofenol foi utilizada como teste preliminar para verificar a atividade catalítica dessas Nps e, em diferentes condições, a reação ocorreu com tempos que variaram de 3 a 10 minutos. Depois, foram empregadas três diferentes metodologias para a síntese de Nps Pd que utilizaram a CMC como agente redutor e estabilizador a fim de eliminar o uso do AA. As três Nps sintetizadas foram usadas para catalisar uma reação de acoplamento entre o ácido fenilborônico e o 4-iodofenol com rendimentos de 68-76 por cento em duas horas. As Nps que obtiveram maior rendimento foram escolhidas para dar prosseguimento ao projeto. Foram caracterizadas por UV-VIS, FT-IR-ATR, DLS, potencial zeta, MEV e EDS e foram utilizadas para catalisar mais três acoplamentos de Suzuki com rendimentos de 74 por cento a 86 por cento. Um suporte lignocelulósico, mecanicamente e termicamente resistente, feito a partir da biomassa de bambu foi funcionalizado com 1-oxil-2,2,6,6-tetrametilpiperidina (TEMPO) e caracterizado por FT-IR-ATR. Foi, então, impregnado para a imobilização de Na2PdCl4 (T_PdCl2) e das Nps Pd reduzidas e estabilizadas com CMC escolhidas (T_PdCMC_R). Os catalisadores desenvolvidos foram caracterizados por FT-IR-ATR, MEV e EDS. O catalisador T_PdCl2 foi utilizado em 4 reações seguidas com perdas de rendimento a cada reação (de 92,2 por cento até 18,4 por cento). Por ICP OES foi determinado que a quantidade de paládio lixiviada foi de 0,20 ppm na primeira reação e de 0,10 ppm nas reações seguintes. O catalisador T_PdCMC_R foi usado para a reação acoplamento entre ácido fenilborônico e 4-iodofenol e, em diferentes condições, obteve rendimentos de 35 por cento e 43 por cento. / [en] Suzuki C-C coupling reaction, since its discovery, has always attracted the interest of researchers and has found application in several fields both in academia and industry. Driven by environmental problems that concern our society so much and by the principles of green chemistry, created to guide chemists towards a sustainable science, researchers have sought to create efficient catalysts for this reaction, which achieve high selectivity in mild reaction conditions. The development of heterogeneous catalysts is motivated by its easy removal from the reaction medium and its possible reuse for a high number of reactions. One approach for creating these catalysts is to anchor metallic ions or metallic nanoparticles (Nps) in supports that facilitate their handling, removal and reuse. In this work, palladium nanoparticles (Nps Pd) reduced by ascorbic acid (AA) and stabilized by carboxymethylcellulose (CMC) were synthesized. These Nps were characterized by UV-VIS, FT-IR-ATR, DLS, zeta potential, SEM and EDS. The 4-nitrophenol reduction reaction was used as a preliminary test to verify the catalytic activity of these Nps and, under different conditions, the reaction occurred with times ranging from 3 to 10 minutes. Then, three different methodologies for the synthesis of Nps Pd using CMC as reducing and stabilizing agent were proposed in order to eliminate the use of AA. The three synthesized Nps were used to catalyze the coupling reaction between phenylboronic acid and 4-iodophenol with yields of 68-76 percent in two hours. The Nps that obtained the highest yield were chosen to be used in the next steps of the project. These Nps were characterized by UV-VIS, FT-IR-ATR, DLS, zeta potential, SEM and EDS and were used to catalyze three more Suzuki couplings with yields of 74-86 percent. A mechanically and thermally resistant lignocellulosic support, made of bamboo biomass, was functionalized with 1-oxyl-2,2,6,6-tetramethylpiperidine (TEMPO) and characterized by FT-IR-ATR. It was then impregnated for the immobilization of Na2PdCl4 (T_PdCl2) and the chosen Nps Pd reduced and stabilized by CMC (T_PdCMC_R). The developed catalysts were characterized by FT-IR-ATR, MEV and EDS. The catalyst T_PdCl2 was used in 4 reactions in a row with yield losses for each reaction (from 92.2 percent to 18.4 percent). By ICP OES it was determined that the amount of palladium leached was 0.20 ppm in the first reaction and 0.10 ppm in the following reactions. The catalyst T_PdCMC_R was used for the coupling reaction between phenylboronic acid and 4-iodophenol and, under different conditions, obtained yields of 35 percent and 43 percent.

In today s world, the need to limit the use of nonrenewable resources and the importance of recycling has been recognized. One important contribution of chemists toward the general goal of limiting their use is to find catalysts that can be reused and recycled thereby limiting the need for expensive metal precursors and metal waste. Strategies to recycle catalysts are multifold and range from the employment of soluble polymers as catalyst supports to the use of membrane-encapsulated catalyst. The use of soluble polymers as a support not only offers the advantage of being soluble under the catalytic reaction conditions but also, to be removable by changing the conditions of the surrounding media. Despite the great potential of these soluble supported catalysts, their use is very limited in today s synthesis. In addition, no set of rules have been established to guide the synthesis of efficient supported catalysts. In order to establish a tool box for the synthesis of supported catalysts, the study of several parameters such as the choice of the support and the choice and the stability of the catalyst are necessary. To establish this set of rules, a limited number of catalytic transformations, were studied. These catalytic reactions are the Heck-Mizoroki, Suzuki-Miyaura and Sonogashira coupling reactions. These transformations became fundamental for the synthesis of drugs and materials. The first and second chapters provide background information by describing and evaluating the main supports that were previously used for catalysts and the two main catalysts that are used in this thesis, the palladium pincer complex and the palladium N-heterocyclic complex. In chapter 3, the synthesis of a soluble polymer supported catalyst is described. The polymer chosen for the study is poly(norbornene), and the catalyst is a 1,3-disubstituted benzene ligand with sulfurs in the side-chains able to chelate to the metal center, better known as pincer ligand. These ligands are abbreviated by the three atoms that coordinate to the metal center, in this study, SCS. The metal used for the investigation of the activity of this supported pincer is palladium. The importance of the nature of the linkage on the stability of the Pd-SCS pincer complex has been reported in the literature, leading to the synthesis of Pd-SCS pincer complex tethered to the polymer via an ether and an amide linkage. The synthesized poly(norbornene) supported Pd-SCS pincer complexes were evaluated using the Heck transformation of iodobenzene with n-butyl acrylate. Kinetic studies and leaching tests using poly(vinyl pyridine) and mercury were carried out resulting in the conclusion that the active species during the catalysis is not the palladium pincer complex but a leached palladium (0) species. In chapter 4, Pd-PCP pincer complexes with the ether and amide tether were synthesized. Kinetic and poisoning studies were carried out resulting in a similar conclusion. Furthermore, 31P NMR experiments were conducted to investigate the unstability of the complex. Following this study, in-situ XAS as well as computational calculations were carried out. The conclusion from this sinvestigation argues that triethylamine is a key ingredient for the decomposition of the Pd-PCP complex. The overall conclusion from these two different studies is thta Pd(II) pincer complexes decomposes during the Heck reaction when triethylamine is used for the coupling of iodobenzene to n-butyl acrylate in DMF at 120 ºC. Stemming from this investigation, a reported more stable complex, Pd-NHC, was tethered onto poly(norbornene). The system was evaluated using Suzuki-Miyaura, Heck and Sonogashira reactions. Similar poisoning and kinetic studies were utilized to investigate the stability of the supported NHC Pd complexes. The result of this investigation suggests that supported Pd-NHC complexes are stable under Suzuki-Miyaura and Sonogashira but decompose under Heck conditions. However, when the system was recycled, a decrease in activity for the Suzuki-Miyaura transformation and solubility was observed. In chapter 6, gold monolayer protected clusters (MPC) were investigated as potential candidates as supports. To examine the potential of MPC as a support, a NHC-Pd complex was graphted onto the particles. To functionalize the gold nanoparticles, a new method was developed. Using azide moieties added to the gold nanoparticles, the catalyst was added via microwave assisted 1,3 dipolar cycloaddition. The system was evaluated using Suzuki-Miyaura transformations under microwave conditions. The system exhibited quantitative conversions for a variety of substrates. However, when the system was recycled, aggregation of the particles and decrease in catalytic activity was observed. In summary, this thesis describes the synthesis and evaluation of poly(norbornene) supported Pd-pincer and Pd-NHC complexes and of gold nanoparticles supported Pd-NHC complex. It also detail the combination of kinetic and poisoning studies developed to evaluate a potential supported catalyst.

Die Immobilisierung homogener Katalysatoren ist eine wichtige Methode zur Realisierung der Abtrennbarkeit und Wiederverwendbarkeit aktiver Spezies. Im Rahmen dieser Arbeit wurde durch die Komplexierung von Palladium mit 1,4-Bis-(4′-pyrazolyl)benzen ein neues mikroporöses Koordinationspolymer generiert und dieses als heterogener Katalysator in der Suzuki-Miyaura-Kreuzkupplungsreaktion erfolgreich eingesetzt. Dabei konnten vollständige Umsätze und hohe Selektivitäten erzielt werden, die vergleichbar zu bereits kommerziell erhältlichen homogenen Katalysatoren sind. Die Besonderheit des Katalysators ist, neben dessen außergewöhnlich hohen chemischen Stabilität, die Variation seiner Struktureigenschaften durch die Wahl der Synthesebedingungen und die damit verbundene Steuerung seiner katalytischen Aktivität.

Des nouveaux catalyseurs bimétalliques à base de palladium et de cuivre ont été développés. Deux voies de préparation ont été testées : l'imprégnation successive (TSI) et la co-imprégnation (CI) en utilisant la zéolithe 4Å (4A) et l'oxyde mixte MgAlxOy comme support. Les catalyseurs ont été caractérisés à l'état frais et testés dans la réaction de couplage Suzuki–Miyaura afin de comparer leurs activités, sélectivités et stabilités. L'étude de stabilité nous a montré que le catalyseur Cu-Pd-4A-TSI restait actif pendant six cycles alors que l'activité du catalyseur Cu-Pd-4A-CI diminuait. Sur le support MgAlxOy, le catalyseur CI était stable pendant six cycles contrairement au catalyseur TSI. Nous avons montré que le point clé pour l'obtention d'une bonne activité et stabilité est la présence de la phase active correspondant à l'alliage Cu/Pd 1/1 identifiée grâce à la caractérisation des catalyseurs et ce quelle que soit la méthode de préparation des catalyseurs. Une différence cruciale existe entre les catalyseurs supportés sur MgAlxOy et 4A : le catalyseur Cu–Pd supporté sur MgAlxOy permet de réduire le temps de réaction de moitié pour une même conversion par rapport à Cu-Pd-4A-TSI. De plus, l'utilisation d'un support plus basique permet, dans une certaine mesure, la diminution de la quantité de la base ajoutée durant la réaction. La réaction Petasis-borono Mannich a été aussi effectuée avec succès sur ces catalyseurs. / New bimetallic palladium/copper catalysts were developed by successive impregnation (TSI) and co-impregnation (CI) on 4Å molecular sieve (4A) and MgAlO mixed oxides supports. The fresh catalysts were characterised and tested in the Suzuki–Miyaura reaction to test their activity, selectivity and stability. It was observed that while the Cu-Pd-4A-TSI catalyst kept its activity during six cycles that of the Cu-Pd-4A-CI dropped. On MgAlO support the catalyst prepared with CI proved to be stable even for six runs contrary to TSI. The active phase of the reaction – namely the Cu–Pd alloy with atomic ratio 1:1 - was determined with the help of catalyst characterisation of the recovered catalysts. This observation confirms that whatever the way of preparation or the support is, the key-point is the presence of Pd-Cu 1:1 particles to enhance the catalytic performances. A crucial difference between the MgAlO and 4A supported catalyst was found in the reaction time necessary for the Suzuki–Miyaura reaction. With the Cu-Pd-MgAl-CI catalyst the reaction time could be reduced to thirty minutes contrary to one hour with Cu-Pd-4A-TSI. Moreover it was concluded that with a more basic support the reduction of the quantity of the base was possible however it brought slightly decreasing yield. The Petasis-borono Mannich reaction was also performed in the presence of each mono-and bimetallic catalysts.

Mechanochromic polymers respond to external force by changing their color. This can be achieved by the incorporation of a molecular switch such as spiropyran (SP) into polymers. SPs can be isomerized by mechanical force from their colorless form into colored merocyanines. Main chain copolymerization of spiropyrans allows investigation of their mechanochromic behavior and potential use as force sensors. So far, several covalent polymer matrices have been used to investigate the mechanochromic response of SPs, among them poly(ε caprolactone) (PCL). Less investigated is how the mechanochromic response can be fine-tuned by substituent effects. First, PCL with differently substituted spiropyrans at the chain’s midpoint were used in order to investigate the effect of different substituents and their regiochemistry on the isomerization behavior of SPs under mechanical stress. A low activation barrier was observed for NO2 substitution of “ortho”-spiropyrans compared to no substitution (R = H). In order to investigate phenyl-substituted “para,para” spiropyrans, a newly developed kinked polyarylene was employed as covalent matrix material. This new polyarylene (PmmpP) has a meta,meta,para connection in its backbone and exhibits excellent mechanical properties. Its high strength allows the isomerization of this molecular switch with a large activation barrier. The phenyl-substituted “para,para” spiropyran showed transient mechanochromism and was switched 25 times in force-and-release cycles. The synthesis of PmmpP was carried out by a Suzuki polycondensation in three steps from commercial starting materials. To further capitalize on the simplicity and properties of PmmpP, a two step synthesis of a semifluorinated kinked polyarylene was demonstrated by direct arylation polycondensation with tetrafluorobenzene (F4). This partially fluorinated PmmpF4 was synthesized with a variety of side-chains. Resulting polymers exhibited a large range of glass transition temperatures, allowing for the production of tailor-made smart materials.