Transition metal-catalyzed olefin hydroacylation represents an atom-economical approach for the synthesis of valuable ketone products. To date, the intermolecular variant of this reaction suffers from several drawbacks, which include limited substrate scope, poor reactivity and/or regioselectivity for non-activated, non-chelating alkene substrates, and competitive reductive decarbonylation pathways that lead to catalyst decomposition. Herein, we report the linear-selective intermolecular hydroacylation of a wide range of electronically diverse olefins with salicylaldehydes employing catalyst loadings as low as 2 mol%. A unique reactivity profile is observed for the chiral C2-symmetric phosphoramidite ligand employed in our catalyst system, and thus, we outline progress made towards the synthesis of new phosphoramidite ligands. We have applied our methodology in the total synthesis of nine octaketide natural products belonging to the dothiorelone, cytosporone, and phomopsin families. Due to recent reports demonstrating the anticancer activity of cytosporone B (Csn-B), we will also discuss progress towards the synthesis of Csn-B analogues.

The ever-worsening environmental crisis has stimulated development of less wasteful “green” technologies. To this end, tandem catalysis enables multiple catalytic cycles to be performed within a single reaction vessel, thereby eliminating intermediate processing steps and reducing solvent waste. Assisted tandem catalysis employs suitable chemical triggers to transform the initial catalyst into new species, thereby providing a mechanism for “switching on” secondary catalytic activity. This thesis demonstrates the importance of highly productive secondary catalysts through a comparative hydrogenation study involving prominent hydrogenation catalysts of tandem ring-opening metathesis polymerization (ROMP)-hydrogenation, of which hydridocarbonyl species were proved superior. This thesis illuminates optimal routes to hydridocarbonyls under conditions relevant to our ROMP-hydrogenation protocol, using Grubbs benzylidenes as isolable proxies for ROMP-propagating alkylidene species. Analogous studies of ruthenium methylidenes and ethoxylidenes illuminate optimal routes to hydridocarbonyls following ring-closing metathesis (RCM) and metathesis quenching, respectively. The formation of unexpected side products using aggressive chemical triggers is also discussed, and emphasizes the need for cautious design of the post-metathesis trigger phase.

Histidine-Domain-Protein-Tyrosine-Phosphatase (HD-PTP) has been classified as a non-transmembrane protein tyrosine phosphatase (PTP), however, its catalytic activity has not been appropriately characterized. In this thesis, the tyrosine phosphatase activity of HD-PTP was characterized. To do so, the HD-PTP protein was successfully purified using the FLAG-TAG purification system and an enzymatic assay was carried out using the DiFMUP fluorogenic substrate. My results suggest that HD-PTP is an inactive PTP that can be reactivated upon the back mutation of a conserved amino acid located in its catalytic domain motif 9, which diverges from the PTP consensus sequence. Interestingly, the gene which encodes for HD-PTP is located within the tumor suppressor region on the human chromosome 3p21.3. Furthermore, we determined through colony formation assays that the active mutation does not affect the tumor suppressor potential of HD-PTP. Although wild type HD-PTP is an inactive tyrosine phosphatase, it may act as a natural trapping mutant, thus preserving its strong binding potential for phosphorylated signaling proteins. Since the active HD-PTP mutant should have lost its ability to bind phosphorylated signaling proteins, it was used in a substrate trapping experiment to identify potential binding partners. Four putative binding partners were then purified and identified through multidimensional protein identification technique (MudPIT). Lastly, cell lines that stably express HD-PTP were generated for future studies in the identification of binding partners.

The present project is related to two aspects of research (i) to develop a new technique to synthesize fine nano-size polymer particles with unique and controllable properties; (ii) to synthesize novel functional polymer nanoparticles aiming to overcome the central challenge that has limited the commercialization of green latex hydrogenation, i.e. the optimal interplay of accelerating the hydrogenation rate, decreasing the required quantity of catalyst, and eliminating the need for an organic solvent. Focusing on these two objectives stated above, the following studies were carried out. (1) Development of Micellar Nucleation Mechanism for Preparation of Fine Polymer Nanoparticles. Polymer nanoparticles below 20 nm with a solid content of more than 13 wt% and a narrow molecular weight polydispersity (~1.1) were prepared using a micellar nucleation semibatch microemulsion polymerization system emulsified by sodium dodecyl sulfate (SDS), with SDS/monomer (methyl methacrylate) and SDS/H2O weight ratios of up to 1:16 and 1:100, respectively. It was found that for benzoyl peroxide (BPO), micellar nucleation is more favorable for the synthesis of smaller polymer nanoparticles than ammonium persulfate (APS), which gives rise to homogeneous nucleation and 2,2'-azobisisobutyronitrile (AIBN), which involves partially heterogeneous nucleation. In the polymerization process, there exists a critical stability concentration (CSC) for SDS, above which the size of the nanoparticles is to be minimized and stabilized. With an increase in the monomer addition rate, the polymerization system changes from a microemulsion system to an emulsion system. A mechanism was proposed to describe the micellar nucleation process of semibatch microemulsion polymerization. This technique will pioneer a significant new way to use a simple but practical method to synthesize narrow PDI polymers, which is a very meaningful new development. (2) Diene-Based Polymer Nanoparticles: Preparation and Direct Catalytic Latex Hydrogenation. At the first stage of this study, poly(butadiene-co-acrylonitrile) nanoparticles were synthesized in a semibatch microemulsion polymerization system using Gemini surfactant trimethylene-1,3-bis (dodecyldimethylammonium bromide), referred to as GS 12-3-12, as the emulsifier. The main characteristic of this GS emulsified system lies in that the decomposition rate of initiator was increased considerably at a low reaction temperature of 50 °C because of the acidic initiation environment induced by GS 12-3-12. The particle size can be controlled by the surfactant concentration and monomer/water ratio and a particle size below 20 nm can be realized. The obtained latex particles exhibit a spherical morphology. The microstructure and copolymer composition of the polymer nanoparticles was characterized by FT-IR and 1H NMR spectroscopy. The effects of the surfactant concentration on the particle size, Zeta-potential, polymerization conversion, copolymer composition, molecular weight, and glass transition temperature (Tg) were investigated. The kinetic study of the copolymerization reaction was carried out, which indicated that an azeotropic composition was produced. The relationship between Tg and number-average molecular weight can be well represented by the Fox-Flory equation. Finally, the semibatch process using conventional single-tail surfactant SDS was compared. In the second stage of this study, the prepared unsaturated nanoparticles were employed as the substrates for latex hydrogenation in the presence of Wilkinson’s catalyst, i.e., RhCl(P(C6H5)3)3. The direct catalytic hydrogenation of poly(butadiene-co-acrylonitrile) nanoparticles in latex form was carried out under various experimental conditions in the presence of Wilkinson’s catalyst without the addition of any organic solvents. In order to appreciate the important factors which influence the nature and extent of this type of hydrogenation, the effects of particle size within the range from 17.5 to 42.2 nm, temperature from 90 to 130 °C, and catalyst concentration from 0.1 to 1.0 wt% (based on the weight of polymer) on the hydrogenation rate were fully investigated. The kinetics study shows that the reaction is chemically controlled with a fairly high apparent activation energy, which is calculated to be between 100 and 110 kJ/mol under the experimental conditions employed. Mass transfer of both hydrogen and catalyst involved in the reaction system was discussed. The analysis of mass transfer of reactants coupled with the reaction kinetics indicated that the catalysis of hydrogenation proceeds at the molecular level. The competitive coordination of the active catalyst species RhH2Cl(PPh3)2 between the carbon-carbon unsaturation and the acrylonitrile moiety within the copolymer was elucidated based on the reaction kinetics of the hydrogenation. (3) Poly(methyl methacrylate)-poly(acrylonitrile-co-butadiene) (PMMA-NBR) Core-Shell Polymer Nanoparticles: Preparation and Direct Catalytic Latex Hydrogenation. PMMA-NBR core-shell structured nanoparticles were prepared using a two stage semibatch microemulsion polymerization system with PMMA and NBR as the core and shell respectively. The GS 12-3-12 was employed as the emulsifier and found to impose a pronounced influence on the formation of the core-shell nanoparticles. A spherical morphology of the core-shell nanoparticles was observed. It was found that there exists an optimal MMA addition amount which can result in the minimized size of PMMA-NBR core-shell nanoparticles. The formation mechanism of the core-shell structure and the interaction between the core and shell domains was illustrated. The PMMA-NBR nano-size latex can be used as the substrate for the following direct latex hydrogenation catalyzed by Wilkinson’s catalyst to prepare the PMMA-HNBR core-shell nanoparticles. The hydrogenation rate is rapid. In the absence of any organic solvent, the PMMA-HNBR nanoparticles with a size of 30.6 nm were obtained within 3 h using 0.9 wt% Wilkinson’s catalyst at 130 °C under 1000 psi of H2. This study provides a new perspective in the chemical modification of NBR and shows promise in the realization of a "green" process for the commercial hydrogenation of unsaturated elastomers.

Increases in vehicle exhaust emission regulations have led to research, development and improvements in catalytic converter technologies for gasoline-powered vehicles since the 1970s. Nowadays, there are strict regulations and standards for diesel engines as well, and one of the regulated species is nitrogen oxides (NOX). The lean NOX trap (LNT) catalyst has been studied and developed for use in lean burn (of which diesel is an example) engine exhaust as a technology to reduce NOX to N2. Typical LNT catalysts contain Pt, which catalyzes NO oxidation and NOX reduction, and an alkali or alkaline earth material for NOX storage via nitrate formation. The catalyst is operated in a cyclic mode, with one phase of the cycle under oxidizing conditions where NOX is trapped, and a second phase, which is reductant-rich relative to O2, where stored NOX is reduced to N2. A recently developed catalyst uses a perovskite material as part of the LNT formulation for the oxidation reactions thereby eliminating the need for Pt in a LNT. This catalyst does include Pd and Rh, added to accommodate hydrocarbon oxidation and NO reduction, respectively. Ba was used as the trapping component, and Ce was also part of the formulation. NO oxidation kinetics over the fully-formulated and bare perovskite material were determined, with NO, O2 and NO2 orders being at or near 1, 1 and -1, respectively for both samples. The fully-formulated sample, which contains Ba supported on the perovskite, was evaluated in terms of NOX trapping ability and NOX reduction as a function of temperature and reduction phase properties. Trapping and overall performance increased with temperature to 375°C, primarily due to improved NO oxidation, as NO2 is more readily trapped, or better diffusion of nitrates away from the initial trapping sites. At higher temperatures nitrate stability decreased, thus decreasing the trapping ability. At these higher temperatures, a more significant amount of unreduced NOX formed during the reduction phase, primarily due to nitrate instability and decomposition and the relative rates of the NOX and oxygen storage (OS) components reduction reactions. Most of the chemistry observed was similar to that observed over Pt-based LNT catalysts. However, there were some distinct differences, including a stronger nitrate diffusion resistance at low temperature and a more significant reductant-induced nitrate decomposition reaction. The perovskite-based lean NOX trap (LNT) catalyst was also evaluated after thermal aging and sulfur exposure. NO oxidation, NOX trapping ability and NOX reduction as a function of temperature and reduction phase properties were evaluated. Similar overall performance trends were seen before and after degradation, however lower performance after thermal aging and sulfur exposure were seen due to sintering effects and possible build-up of S species. Although performance results show that most of the sulfur was removed after desulfation, some sulfur remained affecting the trapping and reduction capabilities as well as the water gas shift (WGS) extent at lower temperatures. The Oxygen storage capacity (OSC) on the other hand was maintained after the catalyst was exposed to thermal aging and sulfur poisoning then desulfation, all of which suggest that the perovskite or Pd components were irreversibly poisoned to some extent.

This thesis described the development of new catalytic system for the conversion of natural gas (methane) to liquid products such as methanol and formaldehyde. This technology can allow the exploitation of small and medium size gas fields without the need to build an expensive gas to liquid plants or long pipelines. The technology is based on a concept of non-separating membrane reactor where an inorganic membrane paper serves as a catalyst support through which a reaction mixture is flowing under mild conditions and short residence times.

Un dels reptes més ambiciosos que té avui en dia la comunitat científica és millorar el coneixement de la reacció d’oxidació de l’aigua que dóna lloc a oxigen, protons i electrons. D’altra banda els epòxids son intermedis de reaccions diverses en la indústria química, particularment per a la síntesi de diversos polímers i “fine chemicals” com ara productes farmacèutics, additius alimentaris o fragàncies. Els aquo complexes mononuclears i dinuclears de ruteni amb lligands polipiridílics han estat estudiats a fons pel nostre grup de recerca i d’altres, convertint-se en catalitzadors útils per a l’oxidació d’aigua i per a l’epoxidació d’alquens. Aquesta tesi vol presentar i discutir els següents temes relacionat: 1. La immobilització de dos nous complexes moleculars del tipus “Ru-Hbpp” capaços d’oxidar aigua, sobre òxids metàl·lics com són el TiO2 i el SiO2 així com fent ús del polímer Nafion per tal d’assolir l’objectiu final de construir una cel·la foto-electroquímica. El comportament catalític d’aquests nous sistemes serà discutit i comparat tant amb les espècies homòlogues moleculars com amb d’altres sistemes similars. 2. La síntesi i caracterització d’un complex dinuclear de ruteni que conté un lligand pont amb disposició bis-facial. La seva reactivitat envers l’oxidació d’aigua i d’olefines i la discussió comparant amb sistemes ja descrits a la literatura també formen part d’aquesta secció. 3. En aquest capítol s’ha plantejat la síntesi d’una nova família de lligands híbrids tetradentats capaços de coordinar el ruteni tant per N com per C, camp en el que se n’han fet diversos avanços. Així mateix descrivim un nou complex dinuclear de ruteni contenint un d’aquests nous lligands. 4. La preparació i caracterització tant espectroscòpica com electroquímica d’una família de complexos que tenen com a fórmula general [RuII(PY4Im)(X)]n+ (X = Cl, n = 1 or X = H2O, n = 2), on PY4Im és el lligand pentadentat 1,3-bis(bis(2-piridil)metil)imidazol-2-ilidè. En aquest apartat també es descriurà l’estudi catalític d’aquestes noves espècies envers l’oxidació d’aigua i alquens. / The understanding of the water oxidation reaction to molecular oxygen is still one of the great challenges faced by scientific community. On the other hand the epoxidation of olefins is a reaction of high relevance in both industry and academia. Epoxides are important intermediates in the chemical industry, particularly for the synthesis of various polymers and fine chemicals, such as pharmaceuticals, food additives, or flavor and fragrance compounds. Mononuclear and dinuclear Ru aqua complexes containing polypyridylic ligans have been recently studied by ourselves and by other groups, and have become a very useful platform for both water oxidation catalysis and the epoxidation of alkenes. In this thesis we present and discuss the following related topics: 1. Immobilization of two new “Ru-Hbpp” molecular water oxidation catalysts onto metal oxides such as TiO2, SiO2 as well as into Nafion in order to succed in the building up of a photo-electrochemical cell. The catalytic performance of these new water oxidation materials will be discussed and compared with their homogeneous counterparts and other related systems previously reported. 2. Synthesis and characterization of a novel diruthenium complex containing the bis-facial hexadentate bridging ligandg Hbimp. Its reactivity towards the oxidation of water and olefins and the comparative discussion with the already reported family of related dinuclear complexes. 3. The synthesis of a new family of tetradentate bridging phthalazine-triazole ligands capable to coordinate a metal centre via both N and C atoms is planned and attempted. The synthesis and characterization of a new dinuclear Ru complex containing one of these ligands is here reported and further discussed. 4. The synthesis and the spectroscopical and electrochemical characterization of a new family of complexes with general formula [RuII(PY4Im)(X)]n+ (X = Cl, n = 1 or X = H2O, n = 2), where PY4Im is the pentadentate 1,3-bis(bis(2-pyridyl)methyl)imidazol-2-ylidene ligand. These results together with the performance of the new species towards the oxidation of water and alkenes will be thoroughly discussed.

A series of bidentate amidate ligands with variable groups R' and R" abbreviated by [R"(NO)R'] and adamantyl substituted tetradentate amidate ligands abbreviated by Ad[0₂N₂] were utilized as ancillaries for Ti, Zr, and Hf. Protonolysis routes into homoleptic amidate complexes, tris(amidate) mono(amido), bis(amidate) bis(amido), and bis(amidate) dibenzyl complexes are high yielding when performed with tetrakis(amido) and tetrabenzyl group 4 starting materials. Many of these complexes have been characterized in both the solid-state and in the solution phase, where in the latter case these complexes are fluxional and undergo exchange processes. Multiple geometric isomers are possible with the mixed N,0 chelate provided by the amidate ligands, and geometric isomerization of bis(amidate) bis(amido) complexes has been examined through X-ray crystallographic and density functional theory (DFT) calculations. Isomerization is dictated largely by the steric bulk present at the N of the amidate ligands, and is proposed to proceed through a K²-K¹-K² ligand isomerization mechanism, which is supported by crystallographic evidence of K¹-bound amidate ligands. The amidate ligand system binds to these metals in a largely electrostatic fashion, with poor orbital overlap, generating highly electrophilic metal centers. The bis(amidate) dibenzyl complexes of Zr and Hf are reactive towards insertion, abstraction, and protonolysis. Insertion of isocyanides into the Zr-C bonds of [DMP(NO) tBu]₂Zr(CH₂Ph₂ results in the formation of ƞ₂-iminoacyl complexes, which can either undergo thermally induced C=C coupling to generate an enediamido complex (aryl isocyanides), or rearrange to generate a bis(amidate) bis(vinylamido) complex (alkyl isocyanides). Benzyl abstraction to generate cationic Zr bis(amidate) benzyl complexes is also possible through reaction with [Ph₃C][B(C₆F₅)4] or B(C₆F₅)₃ Terminal imido complexes with novel pyramidal geometries are generated through protonolysis of bis(amidate) bis(amido) Ti and Zr complexes with primary aryl amines. DFT calculations demonstrate the existence of a Zr⁻₌N triple bond for these complexes. Dimeric imido complexes have been characterized in the solid state, but are not maintained in solution. Cycloaddition reactions of the terminal Zr imido complexes with C=0 bonds result in the formation of proposed oxo complexes and organic metathesis products. Catalytic aminoalkene cyclohydroamination has also been realized with these complexes, generating N-heterocyclic products. A series of kinetic and labeling studies support an imido-cycloaddition mechanism for catalytic cyclohydroamination of primary aminoalkenes with neutral bis(amidate) Ti and Zr precatalysts. The intermediate Ti imido complex, K²-[Dipp(NO)tBu-K¹_[DiPP(No) tBu]Ti=NCH₂CPh₂CH₂CH=CH₂(NHMe₂), has been isolated and characterized in the solid-state and in solution. Amine stabilized imido complexes of this type are invoked as the resting state for the catalytic reaction, and solution phase data support a chair-like geometry, where the alkene is coordinated to the metal center. A diastereoselectivity study supports this proposed solution structure. Eyring and Arrhenius parameters, as well as isolation of a 7-coordinate model imido complex, support a seven-coordinate transition state for the rate-determining metallacycle protonolysis reaction. In contrast, secondary aminoalkene hydroamination catalysis with cationic Zr benzyl complexes is proposed to proceed through a σ-bond insertion mechanism. Proton loss from cationic Zr amido complexes to generate imido species is proposed with primary aminoalkenes, and the resultant neutral imido complexes can catalyze the cyclization of these substrates by the aforementioned imido-cycloaddition mechanism. The ability of the amidate ligand system to promote both mechanisms is unique in the field of alkene hydroamination catalysis.

In order to clarify the role that water plays in the photocatalytic process, changes in the IR and Raman spectra of P25 TiO₂ thin films were observed upon exposure to liquid water. Further investigation of these spectral changes via dehydration of thin films under nitrogen and oxygen of different humidities led to the observation of spectroscopic features that have been assigned to localised surface phonon modes. When the effect of UV irradiation on these features was investigated, a broad IR absorption due to transitions of electrons in shallow traps was detected under dry nitrogen but not under dry oxygen. Further investigation of the photocatalytic properties of P25 TiO₂ showed a complete removal of a stearic acid film. The final products have been tentatively assigned to a mixture of short chain carbonyl species and adsorbed carbonates as well as carbon dioxide and water. The IR spectrum of the fuel cell membrane material Nafion is complex and literature data varies in some of the assignments. The compound perfluoro(2-ethoxyethane)sulfonic acid was used as a model compound for the Nafion side chain resulting in a clearer assignment of the Nafion IR spectrum. In light of these new assignments changes induced in the region 1100-1300 cm⁻� by variation in humidity and ion exchange have been shown to be mainly the result of changes in the sulfonate asymmetric stretching modes. By flowing a series of solutions containing tetramethylammonium ions and perchlorate ions the surface charge characteristics of a Pt black film were determined in the pH range 2-12. There proved to be a weak positive charge below pH 4 and a weak negative charge above pH 9. Between these points there appeared to be no overall charge on the surface. When perfluoro(2-ethoxyethane)sulfonic acid was adsorbed to a Pt black film changes in its IR spectrum indicated a strong binding via interactions between the sulfonate groups and the Pt surface. The nature of the adsorption of Nafion was less clear cut and, whilst adsorption is strong, it seems possible that hydrophobic interactions between the Nafion backbone and the surface are involved.

The oxidation of 4-t-butyltoluene in glacial acetic acid by hydrogen peroxid in a process catalysed by cobalt(II) acetate tetrahydrate and sodium bromide has been studied with the aim of increasing the selectivity towards 4-t-butylbenzaldehyde.