Organic Chemistry Commons^™

Regioselective Tellurination Reactions And Their Utilities, Itunu Comfort Olanrewaju

Masters Theses

This thesis provides a comprehensive study of regioselective tellurination and its applications by integrating experimental and computational techniques, with an aim of synthesizing libraries of organotellurium heterocycles. This study addresses existing challenges in regioselective tellurination, such as unpredictable regioselectivity and avoidance of toxic reagents by harnessing intramolecular Te…O coordination and electrophilic aromatic tellurination. This strategy enables the development of previously poorly accessible compounds including benzotellurazinones, 2-acylaminobenzotellurazoles, and previously unknown 2,3-dihydrobenzo [b] oxatelluranes, which were prepared by antiMarkovnikov anti-addition of TeCl4 to C-C triple bonds. Experimental studies were complemented by computational DFT analyses to provide mechanistic and energetic insight into the …

Synthesis Of A Basket-Shaped Host Molecule Based On P-Tert-Butylcalix[4]Arene Featuring Pyridinyl Groups For Volatile Guest Molecule, Boluwatife S. Ajewole

Masters Theses

Supramolecular and Molecular chemistry offer an expanding array of applications for the development of smart devices, with calixarene-based molecular baskets playing a pivotal role in host-guest chemistry. A key concept in this field is the design of "smart" molecules with gate-like features, which can selectively transport chemical or biochemical species that are volatile, reactive, or sensitive to typical solution environments. These molecular hosts are engineered with predefined groups that respond to external stimuli, such as changes in concentration, temperature, or pH.

Molecular baskets are synthetic host molecules designed to capture guest molecules selectively through adjustable gates. In our study, we …

Rapid Reaction Studies On The Chemistry Of Flavin Oxidation In Urocanate Reductase, Niusha Delavari

Masters Theses

Urocanate reductase (UrdA) is a bacterial flavin-dependent enzyme that reduces urocanate to imidazole propionate, enabling bacteria to use urocanate as an alternative respiratory electron acceptor. Elevated serum levels of imidazole propionate are associated with the development of type 2 diabetes and, since UrdA is only present in humans in gut bacteria, this enzyme has emerged as a significant factor linking the health of the gut microbiome and the metabolic disorder insulin resistance. Here we investigated the chemistry of flavin oxidation by urocanate in the isolated FAD domain of UrdA (UrdA’) using anaerobic stopped-flow experiments at 4 °C. This analysis unveiled …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri

Masters Theses

Heck C-C cross-coupling reaction has been widely employed in synthetic organic chemistry because of its high efficiency and simplicity, however the conventional Heck C-C cross-coupling reaction conditions involve the use of an expensive toxicant phosphine-ligated palladium complexes, and high temperature. To address these drawbacks, a highly efficient, homogeneous photocatalyst based on BODIPY for the Heck C-C cross-coupling reactions of aryl iodide and methyl acrylate in DMF solvent under inert conditions has been developed. The 4-Py-BDP-Pd, 3-Py-BDP-Pd and, 2-Py-BOD-Pd catalysts were synthesized and purified using column chromatography. The optical properties of products and intermediates were studied by UV/vis absorption and fluorescence …

A Novel Palladium Bodipy Photocatalyst For Sonogashira Carbon-Carbon Cross-Coupling, Prahadeesh Nagaretnam

Masters Theses

No abstract provided.

Metal Complexes Of Bis(Pyrazolyl)Methane-Based Ditopic Ligands, Pubudu Nuwan Perera Hapuarachchige

Masters Theses

No abstract provided.

Design, Synthesis, And Characterization Of Chemical Tools To Study Peroxisomal Import, Jhalak N. Timilsena

Masters Theses

Peroxisomes are dynamic and interconnected single lipid membrane bound organelles found in the eukaryotic cells which are involved in various biochemical processes including the b-oxidation of very long chain and branched chain fatty acids, metabolism of reactive oxygen and nitrogen species, and reduction of hydrogen peroxide among others. These organelles are known to host numerous proteins and enzymes depending on the cellular environment. All of the proteins needed in the peroxisomes are encoded in the nucleus and synthesized in the cytosol which are then transported to the peroxisomes with the help of a sophisticated protein-transport machinery. Pex5 is one of …

Organocatalyzed Synthesis Of Epoxides From Chalcones Utilizing Amino Acids, Sabrina N. Kegeler

Masters Theses

The epoxide functional group is important throughout the chemical and pharmaceutical industries, as well as in nature. In the chemical industry, epoxides are present in resins and fragrances. In the pharmaceutical industry, epoxide-containing compounds are used as intermediates in the manufacturing of drugs. In nature, many natural products contain epoxide groups and are used for medicinal purposes, and for models to create synthetic molecules.

One approach to epoxide synthesis involves the use of an alkene precursor, a base, and an oxidizing agent. This is where my investigations began. The first step was to optimize the epoxidation reaction, examining substrate scope, …

Application Of Electrospray Ionization Mass Spectrometry For Ionic Liquids And Their Biodegradation Products, Sepideh Rahbarirad

Masters Theses

Ionic liquids (ILs) are organic salts with unique physico-chemical properties and are used as green alternatives to volatile organic solvents. ESI-MS is a sensitive technique to detect these stable, permanent ions. My research focused on (1) Identification of biodegradation products of ionic liquids and (2) Multiplexed tandem MS by modulation of ionization efficiency.

Studies, have demonstrated that ILs are toxic to the environment, which makes their biodegradability an important consideration. In this work, metabolites generated during the biodegradation of 1-butyl-3-methylimidazolium chloride (BMIM), a degradation resistant and commonly used ionic liquid, are identified using high performance liquid chromatography-mass spectrometry (LC-MS).

Multiplexed …

A Simpler Route To Building Photochromic Cinnamaldehyde Semicarbazones, Byron R. Ebbert

Masters Theses

Photochromic semicarbazones are an interesting group of compounds that show potential in a broad range of applications, including as a more environmentally friendly replacement for photochromic metal complex compounds. Previous work has shown the feasibility to synthesize photochromic cinnamaldehyde semicarbazones (CSCs) from a benzaldehyde and a protected acetaldehyde Wittig reagent. A new, quicker, and cheaper approach to constructing these CSCs from crotonaldehyde was explored in this research. A three reaction sequence would convert crotonaldehyde to a CSC; first, an allylic bromination of the semicarbazone with N-bromosuccinimide (NBS); second, an Arbuzov reaction to prepare the semicarbazone phosphonate; and finally a condensation …

Physicochemical Characterization Of Novel 1,1 0-Phenanthrolines, Dominic Millheim

Masters Theses

1,10-Phenanthroline is a well-known and often-used ligand with a variety of interesting properties and applications to both organic and inorganic chemistry. Interest in novel 1,10-phenanthrolines substituted at the 5- and 6- position has grown recently due to their interesting fluorometric and spectroscopic properties. They have been evaluated recently for applications including chemical sensors, chemical indicators, pharmacological targets and bioactive reagents.

1,10-Phenanthroline, an epoxidated synthetic intermediate, and a novel 5,6- disubstituted aminoalcohol derivative were studied to determine the degree of influence that iterative physical and chemical transformations have on the donor properties of the N-C-C-N pocket. Multiple analytical techniques including potentiometry …

The Nucleic Acid Binding Properties Of The Pwi Motif, Hamideh Keshavarz-Mohammadian

Masters Theses

The PWI motif is a highly conserved domain that contains a Proline-Tryptophan-Isoleucine (PWI) tripeptide sequence, for which it is named. Proteins that contain a PWI motif are known to be involved in the constitutive and alternative splicing and the 3'-end processing of messenger RNA transcripts. The hypothesized role of the PWI motif is to nonspecifically interact with nucleic acids. The PWI motif is capable of binding both doublestranded and single stranded forms of DNA and RNA. The structure of the highly conserved core of the PWI motif reveals that it adopts a four-helix bundle fold. The structured core domain, however, …

Investigations Towards Synthesis Of Cinnamaldehyde Semicarbazone Derivatives And Their Photochromicity By Modifying The Ring, The Linker, And The Semicarbazone, Xiao Xiao

Masters Theses

Cinnamaldehyde semicarbazone was varied in three ways, by altering the ring, the conjugated linker, and the semicarbazone, to investigate how changing the structure affects the photochomicity. The synthesis of 7 hetero- and 2 polycyclic- aromatic semicarbazone variants involved three steps, (a Wittig reaction, hydrolysis, and condensation to the semicarbazone) with cumulative yields of 15% to 52%. Generally, the pyridine series gave lower yields than other synthesized semicarbazones. The Wittig reaction gave cis/trans mixtures in ratios of 2 : 1 to 1 : 7 for the 6 acetals, except for the 3 that went directly to the aldehyde, due to the …

Using Soil Organic Matter As An Iron Chelate To Enhance The Efficiency Of Modified Fenton Oxidition Of Diesel Fuel In Arctic Soils, Mary K. Sherwood

Masters Theses

Laboratory experiments were conducted to investigate the use of modified fenton chemistry on the treatment of three soils from the Canadian arctic, all with abundant soil organic matter, iron and manganese oxides, and diesel fuel contamination. The purpose of these studies was to (I) to assess modified fenton chemistry as a treatment option for petroleum-contaminated arctic soils, and (2) to evaluate the impact of soil organic matter on the modified fenton treatment of soils. Modified fenton treatment was compared for reactions in which ethylenediaminetetraacetate was added as a chelate vs. reactions in which the native soil organic matter was the …

A Hplc Method To Assay Mycotoxins - Fumonisin, Ochratoxin And Zearalenone, Nalini Sadagopan

Masters Theses

A HPLC method to quantitate the mycotoxins Fumonisin B1 (FB1), Ochratoxin A(OA), and Zearalenone (ZON) was developed and validated. Mycotoxins are secondary metabolites of fungi like Fusarium, Asperigillus and Penicillium that contaminate crops. They have a wide array of chemical structures which facilitate their analytical detection.

The analytical method consists of reverse phase chromatography and fluorescence detection. Sample cleanup was performed using SAX and C18 cartridges prior to analysis on the HPLC.

The method developed for FB1 is unique in that it is more sensitive, accurate, and reproducible than the existing methods. Automation is one of the salient features that …

Investigation Of Electron Transfer From Carbonylmetallate Anions To Electron Acceptors, Joseph Kofi Agyin

Masters Theses

This study investigated electron transfer potential of the carbonyl-metallate anions cyclopentadienylirondicarbonyl and methylcyclopentadienyliron-dicarbonyl anions to the electron acceptors 2,2-dinitropropane, 1,1-dinitrocyclohexane, $\alpha$,p-dinitrocumene, methyl cyclopentadienyl-mercury(II) chloride and iodide.

The findings from this study indicated that: (a) the expected products could not be obtained from reactions of the anions with the dinitro-substrates, and (b) the mercurials reacted with the anions but the expected products, (ferrocene and methylferrocene), was the minor product and an unexpected (methyl) cyclopentadienylirondicarbonylmercury(II)-chloride or iodide was the major product.

Synthesis Of Symmetric And "Mixed-Ligand" Homocyclopentadienyl Ruthenocenes, John Adjeiku Amanfu

Masters Theses

No abstract provided.

Synthesis Of Organometallic Polymers, Po-Chang Chiang

Masters Theses

By the middle of the nineteenth century, organic chemists found high molecular weight compounds as by-products of some of their experiments. These compounds were thought of as products of a failed reaction. It was not until sixty years ago that the first polymers were deliberately synthesized. Today polymers are used in almost every facet of life and they are becoming more important with each passing day.

This research project focused on synthesizing conducting organometallic polymers. By linking aromatic rings with transition metals, the resultant polymers should have good electrical conductivity because of the interaction of (a) the p electrons on …

Reductive Cleavage Of Cyclopentadienylmanganese Tricarbonyl, Mani S. Iyer

Masters Theses

Since the isolation of ferrocene in 1951, it has been shown to behave like benzene and may be acylated, sulfonated, metalated, and arylated. Like benzene, it also resists hydrogenation.

Daniel Trifan and Louis Nicholas (1957) were the first to show that ferrocene can be smoothly degraded by lithium and ethylamine. The isolation of free cyclopentadienyl ion on hydrolysis of the reaction mixture indicates that the cleavage leads initially to cyclopentadienyl lithium salt. A similar procedure applied to cyclopentadienylmanganese tricarbonyl also resulted in the formation of cyclopentadienyl lithium salt. This, when added to ferrous chloride, gave ferrocene. This technique can be …

Micellar Catalysis Of Hydrolysis Of Substituted Hydroxamic Acids With Perfluorooctanoic Acid, Zhongyuan He

Masters Theses

The work demonstrated the effects of differently located and substituted phenyl groups, as well as aliphatic groups in the hydroxamic acids, on micellar catalysis with perfluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution.

Kinetic rate constant-surfactant concentration profiles for the decano-, 2,5-dimethylphenylaceto-, 4-isopropylphenylaceto-, 4-phenylbutano-, and 6-phenyl-hexanohydroxamic acids were examined and analysis on the data obtained were reported.

The pseudo-phase ion exchange (PPIE) model has been satisfactorily applied to explain the observed micellar effects.

Further investigation into more appropriately substituted hydroxamic acids is suggested in order to obtain a more complete set of data and further evaluation.

Micellar Catalyzed Hydrolysis Of Hydroxamic Acids By Perfluorooctanoic Acid, Mohammad Hashem Akhavan Tafti

Masters Theses

The work reported herein demonstrated that a perfluorocarboxylic acid does indeed behave as a reactive counterion surfactant exhibiting micellar catalysis, this conclusion was further verified by subsequent experimentation.

Rates of acidic hydrolysis of octano-, phenylaceto-, and 4-bromo phenylacetohydroxamic acid have been determined in aqueous perfluorooctanoic acid--a reactive counterion surfactant system. Typical micellar catalysis was observed for the hydrolysis of octanohydroxamic acid but not for the arylacetohydroxamic acids.

Further investigation into finding a more water soluble surfactant which has reactive counter ions is suggested in order to test the theoretical equation (based on the pseudo phase model) appropriate for this surfactant …

Synthesis And Study Of Novel Quinoxaline Di-N-Oxide And 3-Acyl-2-Methylquinoxaline Di-N-Oxides, Cyprian Okwara Ogbu

Masters Theses

This research project consists of two parts. The first involved the synthesis of a novel quininoxaline di-N-oxide via benzofuroxan. The second part was the use of this compound as a synthetic precursor.

It was assumed that 3,4-dimethylaniline would be successfully converted to 5,6-dimethybenzofurazan 1-oxide (5,6-dimethybenzofuroxan) through a sequence of reaction steps. Fortunately, this assumption was correct as the desired compound was produced. This compound was utilized in synthesizing the novel 3-acetyl-2,6,7-trimethylquinoxaline 1,4-dioxide. From the structure of this adduct, it is believed that it will take part in condensation reactions associated with methyl ketones without disrupting the quinoxaline di-N-oxide framework, and …

Synthesis And Reactions Of A-Diketones And Preparation Of Some New Benzimidazoles, Mohamad Reza Agharahimi

Masters Theses

This report will discuss the synthesis of 2,5-dl-(p-chlorophenyl)-3,4-dioxoadiponitrile and its reactions. This compound exists in the form of 4,4'- dichloropulvinic nitrile which is a precursor to 4,4'-dichk>rovulpinic acid. These compounds have been shown to have antiinflammatory activity in rats.

The benzimidazole and pyridazine derivatives of 4,4'-dichioropulvinic nitrile and the benzimidazole derivative of 4,4'-dichk>rovuipinic acid are another group of compounds that are also believed to have useful biological activities. The Pinner synthesis of imidates is used to make the intermediate to the benzimidazole derivative of 4,4'-dichloropulvinic nitrile.

This report will include the methodology of the reactions and …

A Synthetic Approach To Novel Heterocyclic Herbicides, Paul Antony Pathadan

Masters Theses

The purpose of this research study was to prepare novel heterocyclic herbicides. The first phase of the project was to synthesize 1-(nitromethyl)-4-phthalazone.

In the second phase 1 - (nitromethyl)-4-phthalazone was treated with 1,3-propane-dithio-di-p-toluene sulfonate in presence of sodium hydride to get the target compound 4-(1'-nitro-l,3-dithiane)phthalazone.

It is believed that this compound might block the electron transport system of aerobic cells¹ . So further investigation of this compound may lead to novel herbicides.

The Preparation And Reaction Of Novel Glycosyl Ureas And Thioureas, Robert Scott Johnson

Masters Theses

No abstract provided.

Synthesis Of Pyridine Nucleosides By Cycloaddition Reactions And Synthesis And Condensation Reactions Of 4-Aryl-2-Oxytetronimides, Glenn L. Heise

Masters Theses

Experiment 1: The reaction of various glutaconaldehyde salts (Na⁺ or K⁺) with glycosyl isothiocyanates has resulted in the formation of a novel class of compounds. Relatively mild conditions were utilized for the synthesis which occurs in four steps, and in good yield, starting from glucpseptentaacetate. These reactions were found to be regiospecific. The unique physical and spectral properties of the model compound 1-(2,3,4,6-tetra-0-acetyl-β-D-glycopranosyl)-2-thiono-3-pyridine carboxaldehyde are also discussed.

Experiement 2: Early synthetic methodologies have recently been utilized in the synthesis of 4-aryl-2-oxytetronimides. These compounds have been found to participate in condensation reactions with various substituted o-phenylene diamines. A …

Reactivity Of Some Nitrogen-Containing Compounds At Supercritical Water Conditions, David M. Tiffany

Masters Theses

The use of water at cuperctirical conditions to remove nitrogen from several nitrogen-containing compounds was studied with the purpose of exploring the use of supercritical water as a method of removing nitrogen from the extraction products of coal. Quinoline and isoquinolone were the primary model compounds used with benzonitrile and carbazole also being examined briefly. Reaction conditions varied in temperature (350-500°C), pressure (3500-5200 psi), and water density (0.170-.0.426g/cc). The major products formed by isoquinoline were benzene, toluene, ethylbenzene, and o-xylene as well as nonvolatile tar and char. Quinoline produced aniline and toluidine in addition to those obtained from isoquinoline. Most …

Heterocyclic Syntheses Utilizing Aryl Cyanates, Joseph Eugene Drumm

Masters Theses

No abstract provided.

Cationic And Anionic Micellar Catalyzed Hydrolysis Of Hydroxamic Acids, Douglas Eugene Conran

Masters Theses

The hydrolysis of octanohydroxamic and N-methyloctanohydroxamic acids in the presence of cationic and anionic micelles was investigated. Rate constants were determined for the hydrolyses in cetyltrimethylammonium bromide (ctab), the cationic surfactant, with 0.1111 N NaOH and in sodium 1-dodecanesulfonate, the anionic surfactant, with 0.09270 N HC1 at 50.01 + 0.11°C. The acid hydrolysis and the base hydrolysis of N-methyloctanobydroxamic acid followed the standard model for micellar catalysis.