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N-Heterocyclic carbenes (NHCs) are one of the few ligand systems that can finely tune transition metal catalysts via sterics and electronics. The strong sigma-donating properties of these ancillary ligands allow the development of robust tridentate NHC pincer framework, which has emerged as an alternative to the phosphine pincer ligands. The combination of NHC and pincer systems has resulted in a new generation of catalytically active organometallic complexes reported throughout the literature. -NHC Rh pincer complexes were found to be catalytically active in C-C and C-B bond formation via 1,4dition reactions. In addition, the in-situ generated -NHC Ir(H) pincer complex demonstrated catalytic activity in borylation of arene C-H bonds. Preliminary results are comparable to the C-H borylation results published by Hartwig and co-workers. The -NHC Ir(H) pincer complex may also prove to be a suitable catalyst for alkane dehydrogenation, due to framework similarities of the highly active and durable PCP and POCOP pincer hydride systems. Expansion of group 9 metal sources for transmetalation of the -NHC Zr pincer complex afforded the development of -NHC Rh(CO) and -NHC Co complexes. Group 9 metal carbonyl complexes have been reported as active catalysts in photocatalytic C-H activation of small molecules. Testing of Co sources for transmetalation afforded three rare Co pincer complexes, and the first examples of -NHC Co pincer complexes to date. Development of -NHC pincer complexes with base metals provide cost-effect alternatives to pincer systems with precious metal centers, and is reported herein.

L’allumage par claquage laser non résonant des mélanges réactifs considérés à l’état gazeux et au repos est étudié dans ce travail, principalement avec des mélanges n-décane/air (C₁₀H₂₂+N₂+O₂). Ce système est considéré comme étant prometteur dans les différentes stratégies futures concernant les systèmes d’allumages équipant les moteurs à combustion interne. Le plasma d’allumage est généré en focalisant un faisceau laser de haute intensité pendant quelques nanosecondes. Le laser Nd :YAG opère à 1064 nm, il est choisi comme source laser pour l’ensemble des expériences menées en laboratoire afin de montrer l’effet des paramètres physiques, optiques, thermodynamiques (pression) et chimiques (additifs : H₂O, Ar) sur les caractéristiques de l’allumage. Cette étude met en oeuvre une approche statistique sur l’ensemble des expériences en prenant en compte l’ensemble des mesures prises lors de la combustion. Ce manuscrit offre une base de données expérimentale permettant d’appréhender la combustion et la phénoménologie de claquage laser. / Ignition by non-resonant laser breakdown of quiescent reactive mixtures was considered in this experimental study working with gaseous state. In this work, we mainly study the ignition of n-decane / air (C₁₀H₂₂+N₂+O₂) mixtures. This system is considered promising in different future strategies regarding ignitions systems for internal combustion engines. The breakdown is generated by focusing a high intensity laser beam for a few nanoseconds using Nd: YAG laser operating at 1064 nm, it is chosen as the laser source for all experiments conducted here. The experimental plan conducted allows to examine the effect of physical, optical, thermodynamic (pressure) and chemicals (additives: H₂O, Ar) on the characteristics of the laser ignition. This study implements a statistical approach on all the experimental cases taking into account all the measures during breakdown and combustion. This manuscript provides bibliographic basis for understanding combustion and laser breakdown phenomenology.

Orientador: Paulo Cesar Muniz de Lacerda Miranda / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T08:46:40Z (GMT). No. of bitstreams: 1 Naciuk_FabricioFredo_D.pdf: 5766349 bytes, checksum: f8a483081babf6f2f69d11fe85cf43ec (MD5) Previous issue date: 2014 / Resumo: No presente trabalho, foi estudada a preparação da 5,8-dimetoxisoquinolina através de um expediente baseado na reação de Pomeranz-Fritsh. Na etapa de ciclização deste protocolo foi empregada a N-(2,5-dimetoxibenzil)-2,2-dimetoxietanamina, além de seus dois derivados com o nitrogênio protegido (grupo tosila ou nosila). O núcleo isoquinolíco foi preparado em quatro etapas, a partir de matérias comercialmente disponíveis, com 90% de rendimento. Posteriormente, a 5,8-dimetoxisoquinolina foi submetida à desproteção oxidativa, mediada por NBS ou ácidos trialoisocianúricos, seguida de uma etapa de aminação/oxidação. Assim, quatro produtos naturais foram preparados: as caulibugulonas A e D em cinco etapas e com rendimentos globais de 50% e 26% respectivamente e as caulibugulonas B e C em seis etapas com rendimentos globais de 31% e 61% respectivamente. Ainda, baseado nos estudos de obtenção das caulibugulonas A-D, foi possível preparar dois intermediários sintéticos, a 6-cloro-7-(fenilamino)isoquinolino-5,8-diona e a 7-(fenilamino)isoquinolino-5,8-diona) com rendimentos de 79% (duas etapas) e 45% (one-pot), respectivamente, a partir da isoquinolina. Na sequência, através de ciclização intramolecular promovida por fonte de paládio, a 5H-pirido[3,4-b]carbazol-5,11(10H)-diona foi preparada com 65% de rendimento a partir da 7-(fenilamino)isoquinolino-5,8-diona (via ativação C-H) ou com 50% de rendimento a partir da 6-cloro-7-(fenilamino)isoquinolino-5,8-diona (via arilação direta). Assim, após reações de metilação/redução, a isoelipticina foi preparada com 18% de rendimento global em nove etapas / Abstract: In the present work, the preparation of 5,8-dimethoxyisoquinoline was studied through an expedient based on the reaction of Pomeranz-Fritsh. In the cyclization step of this protocol was applied to N-(2,5-dimethoxy)-2,2-dimethoxyethanamine in addition to their two derivatives with protected nitrogen (nosyl or tosyl group). The isoquinolic core was prepared in four steps from commercially available materials, with 90% yield. Later 5,8-dimethoxyisoquinoline, was subjected to oxidative deprotection, mediated by NBS or trihaloisocyanuric acids, followed by one amination/oxidation step. Thus, the four natural products have been prepared: caulibugulones A and D in five steps and 50% and 26%, overall yield, respectively, and caulibugulones B and C in six steps with overall yields of 31% and 61% respectively. Also, based on studies by obtaining the caulibugulones A-D, it was possible to prepare two synthetic intermediates: 6-chloro-7-(phenylamino)-isoquinoline-5,8-dione and 7-(phenylamino)-isoquinoline-5,8-dione with 79% (two steps) and 45% (one-pot) yield, respectively, from the isoquinoline. Following, through intramolecular cyclization promoted by a source of palladium, 5H-pyrido[3,4-b]carbazole-5,11(10H)-dione was prepared in 65% yield from 7-(phenylamino)isoquinoline-5,8-dione (via C-H activation) or 50% yield from 6-chloro-7-(phenylamino)-isoquinoline-5,8-dione (via direct arylation). Thus, after methylation/reduction reactions, isoellipticine was prepared in 18% overall yield in nine steps / Doutorado / Quimica Organica / Doutor em Ciências

Dans cette thèse, nous nous concentrerons principalement sur l’utilisation de complexes basse-valence de cobalt bien définis de la famille des RCo(PMe3)4 pour l’activation de divers types de liaisons (C–H, Si–H, C–X). Notre but était de développer un système compétitif par rapport au système bimétallique de Yoshikai, mais aussi par rapport aux systèmes onéreux à base de rhodium. Nous avons démontré avec succès que les complexes isolés Co(PMe3)4 et HCo(PMe3)4 étaient des catalyseurs efficaces pour l’hydroarylation de différents alcynes et alcènes via une activation de liaisons C–H. De plus, nous avons fait une étude mécanistique en couplant des marquages au deutérium et des études de chimie théorique. Nous avons déterminé que la fonctionnalisation de liaisons C–H se faisait selon un mécanisme concerté appelé ‘’Ligand-to-Ligand Hydrogen Transfer’’ (LLHT). A partir de ces études, nous avons pu aussi développer une hydrosilylation hautement régio- et stéréosélective d’alcynes permettant d’utiliser un grand nombre de silanes différents. Nous avons pu au cours de cette étude isoler un nouveau complexe de cobalt(III) bis-hydrure jouant un rôle important dans le mécanisme. Enfin, nous décrivons aussi que ces mêmes complexes de cobalt RCo(PMe3)4 sont capables de catalyser l’homocouplage de bromure et chlorure de benzyle en présence de dimethylzinc. Une étude mécanistique préliminaire suggère que la réaction procède par deux transferts mono-électroniques et que le diméthylzinc permet de régénérer le catalyseur. / This thesis has focused on the use of well-defined low-valent cobalt complexes of the family RCo(PMe3)4 for a variety of bond activation (C–H, Si–H, C–X). We aimed to develop a catalytic system that could compete with the previously reported bimetallic systems of Yoshikai and expensive rhodium catalysis. To this end, we successful demonstrated that Co(PMe3)4 and HCo(PMe3)4 are efficient catalysts for the hydroarylation of a broad variety of alkynes and alkenes. In addition, we carried out extensive mechanistic investigations using deuterium labelling experiments and theoretical studies namely DFT. The main finding of these studies was that the C–H bond activation proceeded via a ligand-to-ligand hydrogen transfer mechanism. Following on from this study we then showed that it was possible to carry out the regio- and stereoselective hydrosilylation of internal alkynes with a broad variety of hydrosilanes. During this study we successfully isolated an interesting cobalt(III) intermediate which we believe plays a crucial role in the reaction mechanism. Finally, we report on the ability of these catalysts to efficiently catalyze the homocoupling of benzyl halides in the presence of dimethylzinc. Initial mechanistic investigations suggest that the reaction takes via two single electron transfers and that dimethylzinc act to regenerate the catalyst.

The three ways of synthesis of 5'-deoxy and 5'deoxy-5'-fluoromodified nucleosides derived from known cytostatic compounds was designed. Two routes were successfully developed and target substances were prepared. Third one was unsuccessful due to difficulties with deprotection of the key intermediate.

Au cours de cette thèse, nous nous sommes intéressés à la synthèse de photo-interrupteurs organiques [DAE, di(hétéro)arylethenes] via activation de liaisons sp² C-H d'hétéroaromatiques catalysées par le palladium. Le système catalytique pour l'arylation directe précédemment établi, Pd(OAc)₂/KOAc/DMAc, s'est montré adapté aux nouvelles transformations souhaitées. Cette méthode permet l'accès direct à une grande variété de molécules photo-commutable en peu d'étapes. En outre, concernant le développement de nouvelles procédures de fonctionnalisation de liaisons C-H d'hétéroaromatiques, nous avons constaté que le système catalytique Pd(CH₃CN)₂Cl2/Li₂CO₃/dioxane, pour le couplage de thiophènes avec des chlorures d'arylsulfonyle conduit à des thiophènes β-arylés. Ce nouveau système catalytique peut également être utilisé dans une réaction d'addition conjuguée, en utilisant des énones et des chlorures d'arylsulfonyle en tant que partenaires de couplage. Enfin, nous avons décrit la formation de 4-aryl-1,2,3,4-tetrahydroquinolines via Heck/sp² C-H activation co-catalysée par PdCl₂/CuBr. / During this thesis, we were interested in the synthesis of organic photo-switches [DAE, di(hetero)arylethenes] via palladium catalyzed sp2 C-H bond activation of heteroaromatics. The previously established catalysts system for direct arylation, Pd(OAc)₂/KOAc/DMA, was found to be suitable for the new desired transformations. This method allows the straightforward access to a wide variety of useful photo-switchable molecules in a few steps. Moreover, during the course of further developments of C-H bond functionalization of heteroaromatics, we found that a phosphine free catalytic system, Pd(CH₃CN)₂Cl2/Li ₂CO₃/dioxane, promotes the coupling of thiophenes and arylsulfonyl chlorides to afford unexpected β-arylated products. This new catalytic system can also be utilized in conjugate addition reaction by using enones and arylsulfonyl chlorides as coupling partners. Finally, we describe PdCl2/CuBr co-catalyzed formation of 4-aryl-1,2,3,4-tetrahydroquinolines via cascade desulfitative Heck/sp² C-H activation sequence.

Orientador: Carlos Roque Duarte Correia / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T10:03:33Z (GMT). No. of bitstreams: 1 Azambuja_Franciscode_D.pdf: 29528823 bytes, checksum: e651bbfc392063bea6be92abe74dbcba (MD5) Previous issue date: 2015 / Resumo: Neste trabalho, ativações C-H catalisadas por Pd(II) e Rh(III) foram exploradas para a obtenção de moléculas com potencial atividade biológica, em especial 1,1- e 1,2-diariletanos. Para o paládio, foi investigada a hidroarilação de alcinos de Fujiwara como um método rápido, brando e direto para a obtenção de ?-aril-?-heteroaril acrilatos. Inicialmente, o mecanismo desta reação foi estudada através de estudos de espectrometria de massas e ressonância magnética nuclear para elucidar a atuação do catalisador e os fatores envolvidos na estereosseletividade. Após este estudo, as condições reacionais foram reavaliadas para preparação de ?-aril-?-heteroaril acrilatos em bons rendimentos e seletividades. O paládio também foi usado como catalisador de arilações de Heck-Matsuda empregadas como etapa-chave na síntese de anidridos maleicos diarilados, a partir dos quais novos análogos de combretastatina A4 foram preparados. Estes novos análogos e os adutos da hidroarilação de alcinos de Fujiwara foram submetidos a testes de atividade antiproliferativa em células tumorais humanas. De maneira geral, os produtos de Fujiwara apresentaram melhores perfis de atividades, em especial para linhagens de células de rim e ovário, enquanto que os derivados de anidrido maleico diarilado mostraram-se muito pouco ativos para todas as linhagens. Esta ausência de atividade foi atribuída a interações estéreas desfavoráveis detectadas em estudos preliminares de docagem. Por último, ativações C-H catalisadas por 1,2,3,4,5-pentametilciclopentadienilródio(III) ([Cp*Rh(III)]) foram estudadas em dois projetos diferentes, um envolvendo 1,3-diinos e outro com ?-halo/pseudohalocetonas como parceiros de acoplamento, para a obtenção de diversos bis-heterociclos adjacentes e N-heterociclos monossubstituídos, respectivamente, com ênfase à preparação de núcleos isoquinolona / Abstract: New Pd(II) and Rh(III) catalysed C-H activations methods were developed to the obtaining of potential biologically active molecules, particularly 1,1- e 1,2-diarylethanes. With palladium, the Fujiwara¿s hydroarylation of alkynes was investigated as a fast, mild and direct method to the synthesis of ?-aryl-?-heteroaryl acrylates. Initially, the mechanism of this reaction was studied using nuclear magnetic resonance and mass spectrometry to elucidate the catalyst role and the key factors controlling the stereoselectivity. After, the reaction conditions were optimized in order to prepare the ?-aryl-?-heteroaryl acrylates in good yields and selectivities. The palladium was also applied as catalyst to the Heck-Matsuda arylations employed as the key step to the synthesis of non-symmetric diaryl maleic anhydrides. From such compounds new combretastatin A4 analogs were produced. These new compounds and the Fujiwara adducts were tested against several human tumor cells. The results were much better to the Fujiwara products, especially to kidney and ovary tumor cell lines. In contrast, the diaryl maleic anhydrides derivatives showed very low activity for all kinds of cells tested. This absence of activity was attributed to unfavorable steric interactions detected in preliminary docking studies. Last, the C-H activations catalysed by 1,2,3,4,5-pentamethylciclopentadienylrhodium(III) ([Cp*Rh(III)]) were explored in two different projects: 1) the C-H activation/1,3-diyne strategy to the synthesis of adjacent bis-heterocycles and 2) ?-halo/pseudohaloketones as oxidized alkyne equivalents to the selectively preparation of monosubstituted N-heterocycles, in particular the isoquinolone core / Doutorado / Quimica Organica / Doutor em Ciências

Ces dernières années ont été témoin de l'énorme développement de la chimie organique du fluor. Notamment, l'introduction de groupements fluorés émergents sur des « briques » moléculaires variées a attiré l'attention de la communauté scientifique en raison de leurs propriétés particulières. De plus, la stratégie de fonctionnalisation dirigée de la liaison C-H par catalyse par les métaux de transition, a conduit à une révolution dans le développement de méthodologies synthétiques originales. Par conséquent, la conception de nouvelles approches synthétiques pour l'introduction de groupements fluorés par fonctionnalisation de la liaison C-H catalysée par les métaux de transition est particulièrement attirante. Dans cette thèse, nous nous sommes concentrés sur le développement de nouvelles méthodologies d'introduction directe des groupements fluorés sur des arènes et des oléfines par fonctionnalisation directe de liaison C(sp2)-H catalysée par les métaux de transition. En particulier, nous avons tourné notre attention sur le 2-bromo-3,3,3-trifluoropropène (BTP), un réactif fluoré bon marché et provenant de déchets de l'industrie. Ce dernier est utilisé comme agent de remplacement de halon pour la suppression des incendies et, utilisé comme « brique » moléculaire en synthèse organique (Chapitre 1). La première partie de cette thèse est dédiée au développement de nouvelles méthodologies pour l'introduction directe du groupement CF3-vinyl sur des arènes et des oléfines par fonctionnalisation de la liaison C(sp2)-H catalysée par le palladium. Ensuite, cette approche a été étendue à la fonctionnalisation d'esters α,β- insaturés, bien qu'un mécanisme différent soit probablement impliqué (Chapitre 2). Dans la seconde partie de cette thèse, nous avons développé une nouvelle méthodologie pour l'introduction directe du groupement SCF3 sur des arènes et des oléfines par fonctionnalisation de la liaison C(sp2)-H catalysée par le palladium, utilisant le réactif de Munavalli (Chapitre 3). / Recent years have witnessed a great development of the organofluorine chemistry field. In particular, the introduction of emergent fluorinated moieties onto various scaffolds has attracted attention of the scientific community because of their special properties. Besides, transition metal-catalyzed directed C-H bond functionalization strategy has brought a revolution in the development of original synthetic methodologies, since it allows straightforward and more atom-economical processes. Thus, the design of new synthetic approaches for the introduction of fluorinated moieties by transition metal-catalyzed C-H bond functionalization pathway is particularly appealing. Therefore, in this Ph.D. thesis, we focused on the development of new methodologies for the direct introduction of fluorinated moieties onto arenes and olefins by transition metal catalyzed directed C(sp2)-H bond functionalization. In particular, we turned our attention to the 2-bromo-3,3,3-trifluoropropene (BTP), an inexpensive fluorinated reagent coming from industry waste, used as a potential halon replacement for fire suppression and as a fluorinated building block in organic synthesis (Chapter 1). The first part of this Ph.D. thesis was dedicated to the development of new methodologies for the direct introduction of a CF3- vinyl moiety onto arenes and olefins by a Pd-catalyzed directed C(sp2)-H bond functionalization with BTP. Then, this approach was extended to the functionalization of α,β-unsaturated esters, although a different reaction pathway is probably involved (Chapter 2). In the second part of this Ph.D. thesis, we developed a new methodology for the direct introduction of the SCF3 group onto arenes and olefins by Pd-catalyzed directed C(sp2)-H bond functionalization using the Munavalli reagent (Chapter 3).

La recherche de petites molécules bioactives et la quête de diversité moléculaire sont des sources d’inspiration infinies pour les chimistes de synthèse. Dans ce contexte, l’objectif de ma thèse a été de développer de nouvelles voies de synthèse pour accéder aux squelettes de molécules naturelles complexes, et à élaborer une méthodologie de synthèse polyvalente et modulable permettant l’accès à des composés hétéroaromatiques polyazotés. La première partie de ce manuscrit concerne le développement d’une stratégie de synthèse, vers une plateforme de type amincyclopentitol, dont les représentants naturels, la pactamycine et la jogyamycine, présentent un potentiel pharmacologique établi. Ce projet implique l’utilisation de transferts catalytiques de nitrènes dans des réactions d’aziridination et d’amination C-H. La deuxième partie décrit une approche en synthèse totale d’une nouvelle classe de produits naturels, les raputindoles. L’étape clé est une réaction de cycloaddition [3+2] iridocatalysée permettant de préparer des indanes possédant deux centres asymétriques dont la stéréochimie peut être contrôlée. Enfin, la troisième partie relate le développement d’une réaction domino multi-composant, catalysée par le cuivre, pour la synthèse de composés hétéroaromatiques. Les quinazoline-4(3H)-imines, les quinazoline-4-ones et les benzimidazo[1,2-c]quinazolines peuvent être obtenues via l'assemblage d'un cyanamide, d'un acide boronique et d'une amine, promu par un système catalytique unique. / The search for small bioactive molecules and molecular diversity are constant sources of inspiration for organic chemists. In this context, major developments in the design of always more effective, flexible and environment-friendly synthetic methods were described, in particular thanks to organometallic catalysis. Within this context, this Thesis project deals with the development of synthetic approaches towards natural molecules or simplified analogues, and the development of a new methodologies for the synthesis of nitrogen-containing heteroaromatic compounds.The first part of this manuscript concerns the development of a synthetic strategy towards a cyclopentitol platform, found in the natural products pactamycin and jogyamycin which show a great pharmacological potential. This project involves the use of catalytic nitrene transfers within aziridination and C-H amination reactions.The second part of the project describes a total synthesis approach towards a new class of natural products, the raputindoles. The key step is a [3+2] cycloaddition reaction, catalysed by an iridium complex, to prepare indanes possessing two asymmetric centres whose stereochemistry can be controlled. Finally, the third part is devoted to the development of a domino multicomponent reaction, catalysed by copper, for the synthesis of heteroaromatic compounds. Quinazolin-4(3H)-imines, quinazolin-4-ones and benzimidazo[1,2-c]quinazolines can be obtained from the same catalytic system, by the assembly of a cynamide, a boronic acid and an amine with an unique catalytic system.