Conselho Nacional de Desenvolvimento Científico e Tecnológico / A reação de transformação de metanol em olefinas leves foi investigada sobre as peneiras moleculares HZSM-5, HFER, SAPO-34 e HMCM-22. A caracterização físico-química das amostras foi realizada através das técnicas de FRX, DRX, fisissorção de nitrogênio, MEV, espectrometria no IV com adsorção de piridina e TPD de NH3. O desempenho catalítico das mesmas foi comparado em condições de isoconversão inicial de 755%. Verificou-se que as características ácidas e estruturais exerceram forte influência sobre o desempenho catalítico quanto à atividade, estabilidade e seletividade aos produtos da reação. A amostra mais estável foi a HZSM-5 que apresentou maior densidade de sítios fortes e uma estrutura porosa que permite uma circulação tridimensional das moléculas. Já a menos estável, SAPO-34, apresentou a menor concentração de sítios ácidos fortes dentre os materiais estudados e uma estrutura com cavidades com aberturas estreitas (4Å) que oferecem restrições ao acesso dos reagentes aos sítios ácidos do catalisador. Quanto à seletividade a olefinas, a primeira foi mais seletiva a propeno e a segunda, a eteno. A ferrierita não se mostrou seletiva às olefinas leves tendo apresentado, no entanto, comportamento promissor quanto a formação de DME a partir do metanol. Já a HMCM-22 foi seletiva às olefinas leves e aos hidrocarbonetos com 4, 5 e 6 ou mais átomos de carbono. A influência da temperatura no desempenho catalítico foi investigada variando-se a temperatura de reação (300, 400 e 500C). Verificou-se que para a HZSM-5 e HMCM-22, perda da atividade catalítica foi intensificada a partir de 400C. Quanto à seletividade a olefinas leves, apenas a SAPO-34 não se mostrou sensível a variações na temperatura, efeito este que foi nitidamente observado nos outros três catalisadores: um aumento na temperatura promoveu um aumento na seletividade a olefinas leves no caso da HZSM-5 e da HMCM-22 e queda nesse valor para a HFER / The methanol transformation into light olefins was investigated over the molecular sieves HZSM-5, HFER, SAPO-34 and HMCM-22. FRX, DRX, nitrogen fisisorption, MEV, IR with pyridine adsorption and NH3-TPD techniques were used for the physiochemical characterization of the samples. Their catalytic performances were evaluated and compared at isoconversion initial conditions (755%). It was verified that the acid and structural characteristics strongly affected the catalytic performance with respect to activity, stability and selectivity to the reaction products. The most stable sample was HZSM, which presented higher density of strong sites and a porous structure that permits a tridimensional circulation of the molecules. The least stable was SAPO-34, which presented the lowest concentration of strong acid sites and showed a structure with cavities with narrow openings (4Å). This structure restricts the access of the reactants to the acid sites of the catalyst. In what concerns the selectivity to the olefins, the former catalyst was the most selective to propene and the latter was the most selective to ethene. Although ferrerite was not selective to light olefins, it showed promising behavior concerning the DME formation from methanol. On the other hand, HMCM-22 was selective to the light olefins and the hydrocarbons with 4, 5, 6 or more carbon atoms. The catalytic performance under different reaction temperatures (300, 400 and 500C) was investigated. The lowest catalytic activity was verified under temperatures starting from 400C. SAPO-34 was the only catalyst whose selectivity to light olefins was not sensitive to temperature variations. HZSM-5 and HMCM-22 had their selectivity to olefins increased and HFER had it decreased as the temperature was increased

Dans cette thèse nous avons eu pour but d’étudier la réactivité des complexes à bas degré d’oxydation du fer stabilisés par des ligands phosphines vis-à-vis des substrats insaturés. Cet objectif s’inscrit dans une démarche plus large d’accès à des systèmes catalytiques au fer capables de transformer de manière sélective l’éthylène, par la réaction d’oligomérisation, vers des alpha-oléfines linéaires courtes (butène-1, héxène-1, octène-1), ce qui n’a jamais été rapporté dans la littérature. Pour se faire, le passage par le mécanisme métallacyclique de transformation de l’éthylène est la voie privilégiée. Cependant, les propriétés électroniques et géométriques de ligand requises pour suivre un tel mécanisme, et en particulier son étape clé de couplage oxydant de deux molécules d’éthylène sur le centre métallique, ne sont pas clairement identifiées. Nous rapportons ici dans un premier temps la synthèse d’une bibliothèque de complexes de fer(II) et fer(III) à base de ligands phosphines présentant des propriétés électroniques et géométriques variées. Ces nouveaux complexes sont opportunément testés en tant que catalyseurs, d’une part pour la réaction d’oligomérisation de l’éthylène; mais également en tant qu’espèces réduites in situ en association avec des diènes (isoprène, butadiène) conduisant à leur polymérisation. Afin de nous rapprocher davantage de notre objectif d’accès aux espèces à bas degré d’oxydation du fer, l’emploi d’une voie de réduction en une étape et en conditions douces est rapportée; conduisant à l’isolement et la caractérisation de neuf complexes phosphorés de fer(0) à 18 et à 16 électrons. Bien qu’a priori inactifs vis-à-vis de l’éthylène ou des oléfines plus longues, nous montrons la capacité de ces complexes à promouvoir des réactions de couplage oxydant de substrats insaturés (alcynes) le couplage catalytique de l’éthylène et du butadiène et l’activation de divers composés tels que les silanes ou les halogénures d’alkyles, posant ainsi un premier jalon vers leur optimisation et application en tant que catalyseurs d’autres réactions, et potentiellement dans l’avenir, pour la transformation de l’éthylène. / In this thesis our aim was to study the reactivity of phosphine-based low-valent iron complexes towards unsaturated substrates. This goal is part of a wider approach of access to an iron catalytic system able to transform ethylene in a selective manner, by the reaction of oligomerization, towards short linear alpha-olefins (1-butene, 1-hexene, 1-octene), which is unreported in the literature. To achieve this, going through the metallacyclic mechanism of ethylene transformation is the most likely way. However, the electronic and geometrical features of the ligand required to follow this mechanism, and in particular the key step of the oxidative coupling of two molecules of ethylene to the metal center, are ill-defined. We thus report here in a first part the synthesis of a library of P-based iron(II) and iron(III) complexes bearing varied electronic and geometrical features. These novel complexes are opportunistically screened as catalysts for ethylene oligomerization on one hand, and as in situ reduced species in association with dienes (isoprene, butadiene) leading to the polymerization of the latter substrates, on the other hand. In order to get closer to our goal of access to low-valent iron complexes, the use of a one-pot reduction methodology under mild conditions is reported, leading to the isolation and characterization of nine 18- and 16-electron iron(0) complexes. Even though they do not show reactivity towards ethylene or longer olefins, we demonstrate the ability of these complexes to promote reactions involving the oxidative coupling elementary step of unsaturated substrates (alkynes), the catalytic coupling of ethylene and butadiene and the activation of various compounds such as silanes and organic halides, representing a first milestone towards their optimization and application as catalysts for other reactions, including potentially in the near future, for ethylene transformation

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work aims the synthesis and study of ZSM-5 catalysts for the conversion of ethanol to light olefins, especially, using an alternative and inexpensive route. The ethanol emerges as a renewable source for the production of olefins and the ZSM-5 catalyst has important characteristics for this type of reaction such as acidity, surface area and particle size. The synthesis was carried out in hydrothermal treatment at 170 °C. Were performed two conventional synthesis with templates, using n-Butylamine and tetrapropylammonium hydroxide (TPAOH), and an third and alternative route using a nucleating gel. The catalyst characterization was performed using several techniques (XRD, BET, XRF, SEM and TGA) and was observed the formation of the ZSM-5 structure in all the synthesis methods. The catalysts were evaluated in the ethanol to olefins (ETO) reaction, and was evaluated the influence of the reaction temperature (250 to 450 °C) and SAR (SiO2/Al2O2 ratio) in the selectivity for olefins. The products analyses were made with a gas chromatograph with a FID-type detector. The ethylene yield was above to 80 % for all catalysts, and some above 90 %. Lower SAR values provided higher yields for propylene, around to 9 %. The temperature, SAR and template used in the synthesis influenced in the selectivity. In addition, was evaluated the influence of the catalyst mass, dilution and also its modification with different metals. When the mass was increase, the yield for propylene increased. The catalyst dilution with common sand provided, in some concentrations, greater propylene formation. The nucleating gel method showed to be a viable alternative for ZSM-5 synthesis and its use in the ETO reaction. / Este trabalho relata o estudo da síntese e caracterização de catalisadores ZSM-5 para seu posterior uso na reação de conversão de etanol para olefinas, especialmente utilizando uma rota alternativa mais econômica. O etanol surge como uma fonte renovável para a produção de olefinas e o catalisador ZSM-5 possui importantes características para esse tipo de reação, tais como acidez, área superficial e tamanho de partícula. A síntese foi conduzida de maneira hidrotérmica a 170 °C. Foram realizadas duas sínteses convencionais com direcionadores de estrutura, utilizando n-butilamina e hidróxido de tetrapropilamônio (TPAOH), e uma terceira rota alternativa utilizando um gel nucleante. A caracterização dos compostos sintetizados foi realizada com diversas técnicas (DRX, BET, FRX, MEV e TGA) sendo observada a formação da estrutura de ZSM-5 em todas as técnicas de síntese utilizadas. Os catalisadores foram avaliados na reação de conversão de etanol à olefinas (ETO) e foi avaliada a influência da temperatura de reação (250 a 450 °C) e SAR (SiO2/Al2O3 ratio) na seletividade das olefinas. A análise dos produtos formados foi realizada em um cromatógrafo a gás com detector tipo FID. O rendimento para eteno foi superior a 80 % em todos os catalisadores, sendo para alguns acima de 90 %. Baixos valores de SAR proporcionaram maiores rendimentos para propeno, em torno de 9 %. A temperatura, o valor de SAR e os direcionadores empregados na síntese influenciaram na seletividade. Também, foi avaliada a influência da quantidade de massa do catalisador, a diluição e também a modificação com diferentes metais (Ga, La, In) e um não metal (P). Quando a massa foi aumentada, o rendimento para propeno aumentou consideravelmente. A diluição com areia comum, em algumas concentrações, proporcionou maior formação de propeno. O método de síntese via gel nucleante mostrou ser uma alternativa viável para a síntese de ZSM-5 e seu uso como catalisador na reação ETO.

La valorisation de la biomasse en molécules plateformes, telles que les oléfines pour l'industrie des polymères, rend nécessaire l'adaptation des catalyseurs utilisés en pétrochimie à la transformation de composés fortement hydratés. Ces travaux de thèse ont permis de développer une méthode de caractérisation complète des catalyseurs acides en présence d'eau et en conditions réactionnelles. Cette méthode combine un examen des propriétés catalytiques en étudiant l'effet de l'eau sur des paramètres tels que le temps de contact, la température ou le vieillissement du catalyseur, mais aussi des propriétés physico-chimiques en étudiant la structure et la texture des catalyseurs usés et une études des sites acides en présence d'eau et en température. L'évolution de sites acides a été mesurée par FTIR in situ sous flux continu de NH3 et H2O. Les éventuelles compétitions d'adsorption entre H2O et NH3 mais aussi entre H2O et le réactif ont été estimées par la mesure des chaleurs d'adsorptions de ces espèces. Des oxydes d'intérêt (SnO2/SiO2, WO3/SiO2, TiO2/SiO2 et H4SiW12O40/SiO2) ont été synthétisés. Ces oxydes ont été caractérisés finement, notamment au niveau de leur acidité (utilisation de quatre molécules sondes différentes) / The use of biomass to obtain platforms molecules such as olefins for the polymer industry, require an adaptation of the catalysts already used in petrochemical processing for the conversion of highly hydrated compounds. During this project we developed a method for acid catalysts characterization in the presence of water and in reaction conditions. This method combines an analysis of catalytic properties by studying the effect of water on parameters such as contact time, temperature, or aging of the catalyst, but also of physicochemical properties in studying the structure and texture of spent catalysts and a study of the acid sites in the presence of water and temperature. The acid sites evolution of was measured by FTIR in situ under continuous flow of NH3 and H2O. The possible competition of adsorption between H2O and NH3 but also between H2O and the reactant were estimated by measuring the heat of adsorption of these species. Oxides of interest (SnO2 / SiO2, WO3/SiO2, TiO2/SiO2 and H4SiW12O40 / SiO 2) were synthesized. These oxides have been finely characterized, particularly in terms of their acidity (using four different probes molecules)

Cette thèse porte sur l'élaboration de nouveaux complexes au molybdène bien définis pour la métathèse des oléfines. La majeure partie des travaux porte sur la synthèse et l'étude de la réactivité des acides arylboriniques avec un précurseur au molybdène. La fonction hydroxyle des acides permet de substituer un des deux ligands pyrroles du précurseur Mo(N(2,6 iPr2C6H3))(CHCMe2Ph)(2,5- Me2NC4H2)2 pour conduire à de nouveaux complexes comportant une liaison Mo–O–B. La résolution par diffraction des rayons X a permis de confirmer la structure du complexe Mo(N(2,6- iPr2C6H3))(CHCMe2Ph)(2,5-Me2NC4H2)(OB(Mes)2) (Mes = 2,4,6-Me3C6H2) obtenu ainsi que la nature covalente des liaison Mo–O et O–B. Ce complexe mono boroxy pyrrolure (MBP) s'est avéré actif pour l'homométathèse sélective d'oléfines linéaires modèles (octène-1 et octène-2). L'utilisation d'autres acides arylboriniques synthétisés au laboratoire a permis de générer in situ de nouveaux complexes mono boroxy pyrrolure et de comparer leur réactivité pour la métathèse de l'octène-1 et de l'octène-2 sans les isoler. Nous nous sommes également intéressés à la réactivité de ligands alkoxy fonctionnalisés par une phosphine avec un précurseur du molybdène. L'étude par diffraction des rayons X du complexe chélate pentavalent Mo(N(2,6-iPr2C6H3))(CHCMe2Ph)(2,5- Me2NC4H2)(OCMe2(CH2)2PPh2) a confirmé la formation d'une liaison Mo–P covalente de coordination. Cette liaison renforce la stabilité du complexe vis-à vis de l'air et de l'humidité. Il n'est cependant pas actif pour la métathèse des oléfines linéaires. L'emploi d'acides de Lewis et d'acides de Brønsted comme activateurs de ces complexes chélates a été abordé / This thesis is about the design of new well-defined molybdenum-based complexes for olefin metathesis. The main part of this work dealt with the synthesis and the reactivity of arylborinic acids with molybdenum complexes precursor. Mo(N(2,6-iPr2C6H3))(CHCMe2Ph)(2,5-Me2NC4H2)2 precursor reacted with the hydroxyl moiety of the acid to remove one pyrrolide ligand leading to new complexes bearing a Mo–O–B bond. X-ray diffraction confirmed such structure for Mo(N(2,6- iPr2C6H3))(CHCMe2Ph)(2,5-Me2NC4H2)(OB(Mes)2) (Mes = 2,4,6-Me3C6H2) complex. This mono boroxy pyrrolide (MBP) complex showed activity for model linear olefins homometathesis (1-octene and 2-octene). Screening of more synthesized arylborinic acids lead to in situ generation of new MBP complexes which demonstrated activity for 1-octene and 2-octene homometathesis without requiring their isolation. We also focused on the reactivity of alkoxy ligands bearing phosphine moieties with molybdenum complexes precursor. X-ray diffraction of the five-coordinated Mo(N(2,6- iPr2C6H3))(CHCMe2Ph)(2,5-Me2NC4H2)(OCMe2(CH2)2PPh2) adduct confirmed formation on an strong Mo–P covalent bond. This bond strengthen stability of the complexe towair air and moisture. Nonetheless, this complex did not show activity for linear olefin metathesis. The use of Lewis acids and Brønsted acids as activators for these adducts has been studied and described

Olefins have enjoyed many uses in a wide variety of industries, from car manufacturing to energy production. Energy consuming processes of catalytic dehydrogenation, turning paraffins into olefins, has been commercialised since the early 20th century, while catalytic oxydehydrogenation of paraffins to olefins is still in prototype stages. The conflict between kinetic and thermodynamic yield constraints, has delayed the commercialisation of this process. The solution to achieving the relevant process route is exploitation of the right catalyst at moderate temperatures and pressures. Co5MgAlO is studied under atmospheric pressure and 350°C temperature, to dehydrogenate propane and butane to olefins using oxygen as a reactant. Thermodynamic models showing how many reaction routes are possible under atmospheric pressure were explored. Experimental results for butane to air at ratio of 1:0.8 and 1:1.2 hydrocarbons to air gave better selectivity of 1-butene which was more than 12%. When compared with propane at similar reaction ratios the reaction favoured CO2 at selectivity of more than 95%. / Civil and Chemical Engineering / M.Tech. (Chemical Engineering)

The influence of catalyst characteristics, i.e., acidity and porosity on the product distribution in the cracking of triglyceride-rich biomass under fluid catalytic cracking (FCC) conditions is reported. It has found that the degradation degree of triglyceride molecules is strongly dependent on the catalysts’ acidity. The higher density of acid sites enhances the conversion of triglycerides to lighter products such as gaseous products and gasoline-range hydrocarbons. The formation of gasolinerange aromatics and light olefins (propene and ethene) is favored in the medium pore channel of H-ZSM-5. On the other hand, heavier olefins such as gasoline-range and C4 olefins are formed preferentially in the large pore structure of zeolite Y based FCC catalyst (Midas-BSR). With both catalysts, triglyceride molecules are mainly converted to a mixture of hydrocarbons, which can be used as liquid fuels and platform chemicals. Hence, the utilization of the existing FCC units in conventional petroleum refineries for processing of triglyceride based feedstock, in particular waste cooking oil may open the way for production of renewable liquid fuels and chemicals in the near future. / Bài báo trình bày kết quả nghiên cứu khả năng tích hợp sản xuất nhiên liệu sinh học và hóa phẩm từ nguồn nguyên liệu tái tạo sinh khối giầu triglyceride bằng công nghệ cracking xúc tác tấng sôi (FCC) trong nhà máy lọc dầu. Kết quả nghiên cứu cho thấy xúc tác có ảnh hưởng mạnh đến hiệu quả chuyển hóa triglyceride thành hydrocarbon. Tính acid của xúc tác càng mạnh thì độ chuyển hóa càng cao và thu được nhiều sản phẩm nhẹ hơn như xăng và các olefin nhẹ. Xúc tác vi mao quản trung bình như H-ZSM-5 có độ chọn lọc cao với hợp chất vòng thơm thuộc phân đoạn xăng và olefin nhẹ như propylen và ethylen. Với kích thước vi mao quản lớn, xúc tác công nghiệp FCC dựa trên zeolite Y ưu tiên hình thành C4 olefins và các olefin trong phân đoạn xăng. Ở điều kiện phản ứng của quá trình FCC, triglyceride chuyển hóa hiệu quả thành hydrocarbon mà có thể sử dụng làm xăng sinh học cho động cơ và olefin nhẹ làm nguyên liệu cho tổng hợp hóa dầu.

The thesis entitled “Design and Development of Synthetic Methods using Metal-mediated and Metal-free Redox Reactions: Novel C-H Activations, Reductions and Oxidative Transformations” is presented in 4 chapters Chapter 1; Iodine catalyzed amination of benzoxazoles: efficient metal free route to 2-aminobenzoxazoles under mild conditions. The Chapter 1 of this thesis describes iodine catalyzed C-H activation of benzoxazole with primary and secondary amines to form oxidative aminated products. Selective C-H oxidation is a frontline area of modern chemical research as it offers the opportunities to new avenues and more direct synthetic strategies for the synthesis of complex organic molecules.1 In this context, transition metals such as palladium copper, nickel etc, are used extensively for the functional group directed C-H activation, and thus provides new, rapid, low-cost, and environmentally benign protocols for the construction of new chemical bonds.2 During the past two decades iodine and hypervalent iodine have been focus of great attention as they provide mild, chemoselective and environmentally benign strategies in contrast to toxic metal oxidants.3 In this chapter, a facile metal-free route of oxidative amination of benzoxazole with secondary or primary amines in the presence of catalytic amount of iodine (5 mol%) in aq tert-butyl hydroperoxide (1equiv) and AcOH (1.1 equiv) at ambient temperature, under the solvent-free reaction condition is presented. This user-friendly method to form C-N bonds produces tert-butanol and water as the by-products, which are environmentally benign. A wide range of benzoxazole derivatives containing electron-donating and electron-withdrawing groups were coupled with both primary and secondary amines (Scheme 1). Application of this methodology is demonstrated by synthesizing therapeutically active benzoxazoles by reacting 5-chloro-7-methylbenzoxazole with N-methylpiperazine and N-ethylhomopiperazine to obtain corresponding N-aminatedbenzaxozoles, which exhibit antidiarrhetic activity (Scheme 2).4 Scheme 2 Chapter 2: NIS catalyzed reactions. amidation of acetophenones and oxidative amination of propiophenones Chapter 2 is divided in to 2 parts. Part 1 describes the synthesis of α-ketoamides by using acetophenone and secondary amine in the presence of N-iodosuccinamide and TBHP in acetonitrile at room temperature, whereas Part 2 reveals the synthesis of 2-aminoketones by reacting aryl alkyl ketones and suitable secondary amine in the presence of NIS and TBHP. Part 1: Oxidative amidation, synthesis of α-ketoamide: Alpha α-ketoamides are important intermediates in organic synthesis that are present in a variety of natural products, and pharmaceutically active compounds. Herein, a mild and efficient conversion of acetophenones to α-ketoamide is documented by using aq.TBHP and N-iodosuccinamide (NIS) as a catalyst, at ambient temperature. This amidation reaction was found to be versatile as several aetophenone derivitives containing electron-withdrawing and electron-donating substituents underwent a facile amidation. It was also found that acetyl derivatives of heterocylic compounds could be easily converted to their corresponding ketoamides (few examples are shown in Scheme 3).5 Scheme3 Part 2 of Chapter 2 narrates a novel amination of propiophenone and its derivatives catalysed by NIS in the presence of TBHP to furnish their corresponding 2-aminoketone derivatives (Scheme 4). These derivatives are ubiquitous scaffolds that are present in a wide variety of therapeutic agents. Some of these compounds are used in the treatment of depression, smoking cessation, as monoamine uptake inhibitors, rugs for cancer. They are photoinitiators, precursors to β-aminoalcohols, such as pseudoephedrine analogues. 2-Aminoacetophenone analogues are also important intermediates for the formation of several heterocyclic compounds and are active moieties in several important drugs such as ifenprodil, Scheme 4. Chapter 3: Efficient oxidation of primary azides to nitriles This Chapter is divided in to 2 parts, which presents the oxidation of primary azides to their corresponding nitriles. Part 1: An Efficient oxidation of primary azides catalyzed by copper iodide: a convenient method for the synthesis of nitriles In Part 1, an efficient oxidation of primary azides catalyzed by copper iodide to their corresponding nitriles is reported. Herein, the oxidation of primary azide to nitrile is performed using catalytic amount of copper iodide, and aq TBHP in water at 100 ° C. This methodology is compatible with a wide range of primary benzylic azides that contain electron-donating and electron-withdrawing functional groups. The oxidation was found to be selective and a number of oxidizable functional groups were well-tolerated during the reaction conditions (few examples are shown in Scheme 5).6 Scheme 6 Furthermore, oxidation of secondary azides furnished the corresponding ketones in excellent yields (Scheme 6).6 In the Part 2 of Chapter 3, a non-metal catalysed oxidation of primary azides to nitriles at ambient temperature is reported. This part reveals the oxidation of primary azides to nitriles by employing catalytic amounts of KI (25 mol%), DABCO (25 mol%) and aq. TBHP (3 equiv., 70% solution in water). This reaction provides a good selectivity, as double and triple bonds were not oxidized under the reaction conditions. Additionally, chemoselective oxidation of benzylicazides against aliphatic azides increases the potential application of the present method (Scheme 7).7 Chapter 4: Chemoeselective reduction of olefins Part 1: Iron chloride catalysed aerobic reduction of olefins using aqueous hydrazine at ambient temperature Chapter 4 describes the reduction olefins and acetylenes, which is presented in two Parts. Part 1 documents utility of hydrazine (1.5 equiv) for the chemoselective reduction of nonpolarised carbon-carbon bond using iron catalysts. In this part, a chemoselective reduction of alkenes and alkynes in the presence of a variety of reducible functional groups is demonstrated (Scheme 8). The highlight of the present method is that the reduction proceeds well at room temperature and requires only 1.5 equiv of hydrazine hydrate. The olefin reduction by hydrazine depends upon the controlled release of diimide during the reduction. Generally, metal catalyzed reduction of olefins employ a large excess of hydrazine (10-20 equiv), which might be attributed to uncontrolled release of diimide during the reduction.8 Scheme 8 Part 2: Guanidine catalyzed aerobic reduction: a selective aerobic hydrogenation of olefins using aqueous hydrazine In Chapter 4, part 2, organocatalytic generation of diimide and its utility to reduce the double bonds is presented. Generation of diimide in situ by using organo catalysts and its use for the reduction of carbon-carbon double bond is one of the interesting topics in organic chemistry. It has been shown in this part of the thesis that the reduction of olefin at room temperature can be efficiently performed by using 10 mol% of guanidine nitrate, 2 equiv of aqueous hydrazine in oxygen atmosphere. This method tolerates a variety of reducible functional groups such as nitro, azido, and bromo and protective groups such as methyl ethers, benzyl ethers, and Cbz groups. It is also shown that terminal olefin can be selectively reduced in the presence of internal olefin (Scheme 9). Unlike other methods that employ diimide strategy, the present method is shown to be efficient in reducing substrates those contain internal double bonds such as cinnamyl alcohol and its derivatives

The research described in this thesis originated from an idea to develop new body protection for the sport of fencing. The ultimate goal is to develop body armour which would be flexible, wearable, washable, light and breathable, offer protection from injuries and cover the entire body of a sportsman. A new material which exhibits shear thickening behaviour has been specially developed for this purpose in the process of this investigation. The material was designed and synthesised as a soft polymeric system which is flexible, chemically stable and able to increase the value of its modulus of elasticity upon impact at a high strain rate, while remaining in its soft gel-like elastomeric state when low strain rate deformation is applied. The polymeric system that has been developed is based on interpenetrating polymeric networks (IPN) of immiscible polyurethane/urea-ester/ether and poly(boron)n(dimethylsiloxane)m (where on average m ≈ 16 n). In addition, as the polydimethylsilane (PDMS) based polymeric system strongly tends to phase separation, the siloxane polymeric network was chemically cross-linked to the polyurethane polymeric network through polyurethane chemical cross-link-bridges. In order to introduce polyurethane cross-links to a siloxane-based polymeric network, some of the attached methyl groups in the PDMS polymeric backbone were substituted by ε-pentanol groups. The resulting polymeric system combines properties of an alternating copolymer with IPN. The actual substitution of the methyl groups of PDMS into alternating ε-pentanol groups was performed by Grignard reaction of trifunctional chlorosilane monomers, magnesium and 1,5-dibromopentane. Chemical analytical techniques like FT-IR, 13C NMR and 1H NMR spectroscopy were used to reveal the chemical structure of the synthesised polymeric network. The mechanical and dynamical properties of the obtained polymeric system were analysed by dynamic mechanical analysis (DMA). This part of the investigation indicated that the novel polymeric system exhibited shear thickening behaviour, but only at a narrow diapason of deformations (i.e., deformations between 2 to 3 % of the length of the sample). At this limited diapason of deformation an effective increase of the modulus of elasticity from 6 MPa (at lower frequencies, i.e., up to ≤6 Hz of the applied oscillating stress) to 65 MPa (at frequencies between 12.5 to 25 Hz) was obtained. However, no increase in the modulus of elasticity was recorded at deformations below 1.5 % or above 3.5 % of length of the sample at the same frequencies (0 to 25Hz) of the applied oscillating stress.

Ce projet de recherche consiste en l’étude de la réactivité et de la sélectivité de nouveaux catalyseurs de métathèse d’oléfines à base de ruthénium lors de réaction de fermeture de cycle par métathèse d’oléfines (RCM). L’emphase de cette étude repose sur l’évaluation de nouveaux catalyseurs possédant un ligand NHC (carbène N-hétérocyclique) C1-symétrique développés par le laboratoire Collins pour des réactions de désymétrisations asymétriques de méso-triènes par ARCM. Le projet a été séparé en deux sections distinctes. La première section concerne la formation d’oléfines trisubstituées par ARCM de méso-triènes. La seconde section consiste en la formation d’oléfines tétrasubstituées par le biais de la RCM de diènes et de la ARCM de méso-triènes. Il est à noter qu’il n’y a aucun précédent dans la littérature concernant la formation d’oléfines tétrasubstituées suite à une désymétrisation par ARCM. Lors de l’étude concernant la formation d’oléfines trisubstituées, une étude de cinétique a été entreprise dans le but de mieux comprendre la réactivité des différents catalyseurs. Il a été possible d’observer que le groupement N-alkyle a une grande influence sur la réactivité du catalyseur. Une étude de sélectivité a ensuite été entreprise pour déterminer si le groupement N-alkyle génère aussi un effet sur la sélectivité des catalyseurs. Cette étude a été effectuée par l’entremise de réactions de désymétrisation d’une variété de méso-triènes. En ce qui a trait à la formation d’oléfines tétrasubstituées, une étude de la réactivité des différents catalyseurs a été effectuée par l’intermédiaire de malonates de diéthyldiméthallyle. Il a encore une fois a été possible d’observer que le groupement N-alkyle possède un effet important sur la réactivité du catalyseur. Une étude de sélectivité a ensuite été entreprise pour déterminer si le groupement iv N-alkyle génère aussi un effet sur la sélectivité des catalyseurs. Cette étude a été effectuée par l’entremise de réactions de désymétrisation de différents mésotriènes. / This research consists in the study of the reactivity and selectivity of new chiral Ru-based olefin metathesis catalysts in ring-closing metathesis (RCM) reactions. The study focused on evaluating new catalysts possessing C1- symmetric NHC (N-heterocyclic carbene) ligands developed in our laboratories for asymmetric desymmetrization reactions of meso-trienes. The research was divided into two distinct sections, the first concerns the asymmetric ring closing metathesis (ARCM) processes that form trisubstituted olefins from meso-trienes. The second concerns the RCM and ARCM processes that form tetrasubstituted olefins from meso-trienes. It can be observed that there is no precedent in the literature concerning the formation of tetrasubstituted olefins via ARCM. During the investigation concerning the formation of trisubstituted olefins, a kinetic study was done to have better understanding of the catalyst selectivity. With this study in hand, it was possible to observe the effect induced by the N-alkyl group on the catalysts’ reactivity. A selectivity study was done to observe if the Nalkyl group could affects the catalysts’ selectivity. These investigations were done using a variety of meso-trienes in desymmetrization reactions to afford trisubstituted olefins. Concerning the formation of tetrasubstituted olefins, the catalysts’ reactivity was investigated in RCM processes involving diethyldimethallyl malonates. Once again, an effect induced by the N-alkyl group was observed concerning the reactivity of the catalysts. A selectivity study was performed. As for ARCM processes forming trisubstituted olefins, the N-alkyl group also had an impact on the selectivity of the catalysts. This investigation was done with ARCM desymmetrization of meso-trienes.