The behavior of Deepwater Horizon crude oil and other sources of oil were investigated when exposed to sunlight in aquatic systems under environmentally relevant conditions. This research decoupled the abiotic and biotic weathering modifications of oil by focusing solely on the photochemical transformations of oil in aquatic systems. Photochemical rates and mechanisms were measured through the determination of reactive transients. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. Photochemical production of singlet oxygen from thin oil films over seawater and pure water was measured with furfuryl alcohol as a selective chemical probe. The loss of furfuryl alcohol and the formation of 6-hydroxy(2H)pyran-3(6H)-one were monitored. Photochemical production of organic triplets from 6 different compositions of petroleum was measured through the cis-trans isomerization of 1,3 pentadiene in Gulf water. The data correlate very well with previously measured singlet oxygen concentrations. The energies were measured in the range of 280-300 kJ/mol. Macondo Well Oil from the Deepwater Horizon (DWH) rig was mixed with pure water and seawater and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid-liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI). These fractions were analyzed by FT-ICR MS to catalogue molecular-level transformations that occurred to oil-derived WSOs after solar irradiation. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. Time series studies were performed to observe the changes in WSO composition. The predominance of higher-order oxygen classes indicates that multiple photochemical pathways exist that result in oxidation of petroleum compounds. More oxygenated compounds were observed in the WSO acid fraction of oils with higher API gravity.

Les biocarburants issus de la transformation de la biomasse de deuxième génération (2G), devraient remplacer les carburants fossiles dans le secteur des transports. Cependant, ces biocarburants peuvent contenir de 0.5 à 7.0 pds. % de composés oxygénés résiduels, en particulier des molécules phénoliques qui pendant la combustion dans le moteur peuvent se transformer en benzène qui est fortement cancérigène. Dans ce contexte, le défi qui se présente est de développer un processus d'adsorption sélectif pour éliminer les composés oxygénés de type phénolique des carburants liquides. Pour la première étape de notre travail, nous avons utilisé des calculs DFT pour sélectionner un matériau poreux approprié dans la famille des faujasites échangées aux cations monovalents (cation = H+, Li+, Na+, Cs+, Ag+ et Cu+) afin de trouver une formulation zéolitique avec une très forte affinité pour le phénol en présence d'eau et de toluène (molécule modèle de biocarburant). Nous avons trouvé que l’introduction de sites acides de Brønsted et de Lewis dans la structure de faujasite serait un moyen approprié de purifier sélectivement les biocarburants de deuxième génération en éliminant les molécules de phénol. La deuxième étape consiste à étudier en détail l'élimination du phénol dans une solution d'isooctane sur une faujasite contenant les protons qui ont été considérés comme de bons cations lors de la première étape. Au cours de cette étape, nous nous sommes concentrés sur l'effet du rapport Si/Al sur les capacités d'adsorption et de régénération des zéolithes étudiées. Nous avons utilisé une combinaison puissante de deux types de techniques de modélisation : i) la théorie de la fonctionnelle de la densité (DFT) qui a été utilisée pour déterminer les énergies de liaison du phénol avec plusieurs types de formulations de faujasite, ii) les simulations de type Grand Canonical Monte Carlo (GCMC) qui ont été utilisées pour trouver les capacités d’adsorption de chaque zéolite protonée utilisée. Les résultats obtenus sont comparés à ceux mesurés expérimentalement par la spectroscopie infrarouge, les courbes de percée et les expériences de désorption. Nous avons trouvé que le phénol était éliminé sélectivement de l'isooctane dans les zéolithes HY (Si/Al = 2.5) et USY (Si/Al = 47), avec une capacité maximale d'adsorption de 2.2 mmol·g-1, ce qui correspond à 3 − 4 molécules de phénol par supercage d'une structure de faujasite. La capacité maximale d'adsorption a été atteint plus rapidement dans la DAY (Si/Al = ∞), en raison de la présence de grands pores qui dépendent de la faible densité de sites acides. Nous avons également montré que les zéolithes USY ont une bonne capacité de régénération par rapport aux faujasites à forte concentration de sites protonés. En effet, après désorption à température programmée, il existe une très petite quantité de phénol résiduel dans la faujasite contenant une petite quantité de sites protonés, en accord avec la faible énergie d’adsorption du phénol théorique pour cette formulation. / Biofuels from the transformation of second-generation biomass (2G) are expected to replace fossil fuels in the transport sector. However, the biofuels obtained after the co-treatment (bio- oil refining) still contain 0.5 to 7.0 wt% oxygenated compounds, in particular phenolic molecules, which leads to form carcinogenic benzene during combustion in the engine. In this context, a new challenge is to use selective adsorption to remove phenolic compounds from liquid fuels. As a first step in our work, we used DFT calculations to design a suitable porous material in the family of faujasites exchanged with monovalent cations (cation = H+, Li+, Na+, Cs+, Ag+, and Cu+) in order to find a zeolitic formulation with a high affinity for phenol in the presence of water and toluene (biofuel model molecule). We have found that increasing the amount of the protonated and Lewis acid sites in the faujasite structure would be an appropriate mean of selectively purifying second-generation biofuels by removing phenol molecules. The second step is to study the removal of phenol from an isooctane solution over a faujasite containing protons that was considered as a good cation in the first step. Herein, we focused on the effect of the Si/Al ratio on the adsorption and regeneration capacities of the studied zeolites. For this deeper investigation, we have used a powerful combination of two types of modeling techniques: i) density functional theory (DFT) was used to determine the binding energies of phenol with several types of faujasite formulations, ii) the Grand Canonical Monte Carlo (GCMC) was used to find the adsorption capacities of each used protonated zeolite. The obtained results are compared with those measured by various experimental tools (infrared spectroscopy, breakthrough curves and desorption experiments). As results, we have found that phenol was selectively removed from isooctane into HY (Si/Al=2.5) and USY (Si/Al=47) zeolites with a maximal adsorption capacity of 2.2 mmol·g−1, which corresponds to 3−4 phenol molecules per supercage of a faujasite structure. The adsorption equilibrium was reached more rapidly in DAY (Si /Al = ∞) compared to faujasites with a large amount of protonated sites, due to the presence of large pores at the expense of micro porosity as well as a low density of acidic sites. We have also shown that USY zeolites have good regenerative capacity compared to faujasites with high amounts of protonated sites. Indeed, after temperature programmed desorption, there is a low amount of residual phenol in the faujasite containing a small amount of protonated sites, in agreement with our low adsorption energy of phenol computed for this formulation.

The homoaldol reaction is one of the most powerful methods for the construction of C–C bonds as well as 1,4-oxygenated compounds yet this reaction remains in challenging tasks due to the instability of homoenolates which spontaneously cyclize to the cyclopropanolate. A regioselective catalytic homoaldol equivalent reaction of 3-bromo vinyl acetate with aldehydes under Cr(III)-Mn(0) redox condition was developed. This homoaldol equivalent reaction allows access to the 1,4-oxygenated compounds that are not possible by a conventional aldol process. Mild hydrolysis of the vinyl acetate and reduction of the homoaldol adducts generated diols and lactols in high yield (99%). Further manipulation including stereoselective epoxidation and cyclopropanation was achieved in an efficient manner. Furans, found in many natural products and utilized in drug discovery, have been well studied but current synthetic methods toward furans have some limitations in functional group tolerance, substrate scope, and low product yield in many cases. A highly efficient and catalytic cycloisomerization reaction that transforms acetylenic α,β-epoxides to 2,3,5-tri-substituted furans under InCl3 catalysis was developed. This reaction sequence allows access to rapid construction of highly valuable, tri-substituted furan derivatives. Cross-coupling reactions utilizing transition metals and Lewis acids are important synthetic tools for the formation of C–C and C–N bonds and a number of cross-coupling reactions between α-bromo carbonyl compounds and metal reagents such as aryl metals, alkenyl metals, and alkyl metals have been reported. Transition metal-catalyzed cross-coupling reaction for the construction of α-alkynyl carbonyl compounds has reported in a limited case. The first approach to secondary α-alkynyl carbonyl compounds from secondary α-bromo esters and amides with tributyl(phenylethynyl)stannane under palladium-catalyzed cross-coupling reaction conditions was developed. This synthetic method allows access to secondary α-alkynyl carbonyl compounds which are valuable precursors in pharmaceuticals and agricultural applications.