Organic Chemistry Commons^™

Synthesis And Study Of High-Spin Stable Organic Radicals For Electrical Conductors And Mannosamine Nitroxide For Mri Contrast Agents, Shuyang Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

In the first project, we describe the synthesis of an ambient stable high spin organic diradical 4 based on the Blatter moiety. The high-spin (S = 1) organic diradical 4, which consists of two Blatter radical moieties in a conjugated structure, exhibits a nearly exclusive population (88%) on triplet ground state at room temperature as a consequence of a large single-triplet energy gap (ΔEST = 0.5 kcal/mol). The target diradical molecule is synthesized over five steps with structural confirmation by single-crystal X-ray diffraction. The thermogravimetric analysis (TGA) shows the onset of decomposition at ~264 oC, indicating the diradical molecule has …

The Kappa Opioid Receptor Agonist 16-Bromo Salvinorin A Has Anti-Cocaine Effects Without Significant Effects On Locomotion, Food Reward, Learning And Memory, Or Anxiety And Depressive-Like Behaviors, Ross Van De Wetering, Amy Ewald, Susan Welsh, Lindsay Kornberger, Samuel E. Williamson, Bryan D. Mcelroy, Eduardo R. Butelman, Thomas E. Prisinzano, Bronwyn M. Kivell

Markey Cancer Center Faculty Publications

Kappa opioid receptor (KOR) agonists have preclinical antipsychostimulant effects; however, adverse side effects have limited their therapeutic development. In this preclinical study, conducted in Sprague Dawley rats, B6-SJL mice, and non-human primates (NHPs), we evaluated the G-protein-biased analogue of salvinorin A (SalA), 16-bromo salvinorin A (16-BrSalA), for its anticocaine effects, side effects, and activation of cellular signaling pathways. 16-BrSalA dose-dependently decreased the cocaine-primed reinstatement of drug-seeking behavior in a KOR-dependent manner. It also decreased cocaine-induced hyperactivity, but had no effect on responding for cocaine on a progressive ratio schedule. Compared to SalA, 16-BrSalA had an improved side effect profile, with …

Design, Synthesis, And Kinetic Study Of The First Generation Phenyloxadiazole Compounds And The Second Generation Phenyloxadiazole Compounds And Highly Selective Hydroboration Of Alkenes, Ketones And Aldehydes Catalyzed By A Well-Defined Manganese Complex, Haisu Zeng

Dissertations, Theses, and Capstone Projects

This thesis focuses on two projects. In the first project, my goal was to discover a new variant of phenyloxadiazole compounds that could exhibit increased thiol-reactivity during bioconjugation processes. To achieve this, I synthesized several phenyloxadiazole derivatives and subjected them to NMR kinetic studies to assess their reactivity with a model thiol. Based on the results, I was able to identify a phenyloxadiazole analog that demonstrated enhanced reactivity, which included a chlorine atom located in the meta-position of the phenyl ring.

I provided a detailed description of the synthesis and characterization of the newly discovered phenyloxadiazole analog and demonstrate its …

Design, Synthesis, Biological And Computational Studies Of Flavonoid Acetamide Derivatives, Daniel Kasungi Isika

Dissertations

Flavonoid compounds (FC) have extensive biological applications through potent antimicrobial, anti-inflammatory, anticancer, antidiabetic, and antioxidant properties. These applications are nevertheless limited by low bioavailability, poor aqueous solubility, enzymatic degradation, rapid metabolism, and fast body clearance. FC show unique structure-activity relationships (SARs) essential in assessing and mitigating the prevalent challenges impeding their applications. These challenges can be addressed by structural modification of the FC through functionalization of the phenolic rings, modification of the ketone group, and modification of the phenolic hydroxyl groups with bioisosteres.

The objectives of this work are to (i) design and synthesize novel flavonoid acetamide derivatives (FADs) and …

Synthesis Of An Acinetobacter Baumannii Lipooligosaccharide Subunit, James M. Armstrong Ii

LSU Doctoral Dissertations

Acinetobacter baumannii is a Gram-negative, multi drug-resistant bacterium that was placed on the World Health Organization’s watchlist of drug-resistant bacteria. A. baumannii is an ESKAPE pathogen, one of six increasingly antimicrobial-resistant bacteria that are responsible for nosocomial infections. Alternative therapies, such as vaccines, are required to decrease the world’s reliance on antimicrobial agents. Specifically, glycoconjugate vaccines such as those used against Haemophilus influenzae B, Streptococcus pneumoniae, and Neisseria meningitidis are used globally and are highly effective. These vaccines consist of an antigenic bacterial glycan bound to a carrier protein. The glycan is usually a capsular polysaccharide (CPS), however, the notion …

Computer-Aided Drug Design Of Bakuchiol-Inspired Lxrα Modulators Against Acute Lymphoblastic Leukemia, Dillon P. Cao

LSU Master's Theses

Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children, accounting for approximately 25% of pediatric malignancies. Although glucocorticoids are commonly used to treat ALL, prolonged use can lead to steroid resistance, rendering the drug regimen ineffective. Therefore, alternative treatment avenues are needed for high- risk pediatric patients that do not respond well to traditional regimens.

Liver X Receptor α (LXRα) is presented as a potential alternative drug target for pediatric patients that exhibit suboptimal response to glucocorticoids. Limitations of the current LXRα modulators such as indiscriminate isoform selectivity between LXRα and LXRβ and consequent adverse effects …

Photoacid-Catalyzed C–C And C–O Bond Formation And The Synthesis Of Triazole - Containing Bis(Indolyl)Methanes, Jason Saway

Seton Hall University Dissertations and Theses (ETDs)

From photosynthesis to transition metal-type photocatalysts, the conversion of light energy into chemical energy is a fundamental process in chemistry. While photochemistry is not new to the world of science, there has been a renewed interest in the field, specifically with the use of photocatalysts. There is a wide variety of compounds that function as photocatalysts, ranging from transitions metal complexes, organic dyes, and photoacids. Photoacids, which have typically been used for polymer synthesis and the pH modulation of biological systems and have recently gained popularity due to their catalytic potential. These compounds offer an efficient, cost-effective way to conduct …

Visible Light Photoacid Generator Catalyzed Michael Additions & In-Situ Photoredox Generated Carbocation Catalysis, Zena M. Salem

Seton Hall University Dissertations and Theses (ETDs)

Proton transfer is essential in many natural and chemical processes, and photoacids that undergo proton dissociation or generation upon photoirradiation can be beneficial for use in acid-sensitive reactions. This work describes the use of photoacid generators (PAGs) as tools for organic synthesis, generating strong acids upon light absorption catalyzing Michael addition reactions. Specifically, visible-light-induced PAGs were used to facilitate the 1,4-conjugate addition between indoles and vinyl ketones. Furthermore, carbocations have gained attention as Lewis acid catalysts in a variety of reactions providing good selectivity and yields. We also demonstrate the viability of in-situ photoredox-generated carbocation catalysis in the context of …

A Synthetic Approach To The Optimization Of Silicon-Rosindolizine Swir Fluorophores, Timothy Lewis

Honors Theses

Fluorophores emitting within the near-infrared (700 – 1000 nm) or shortwave-infrared (1000 – 1700 nm) regions of the electromagnetic spectrum are of particular interest for their potential to supplement or even outright replace commonly used biological imaging techniques, such as magnetic resonance imaging and computed tomography scanning. Various characteristics make these molecules particularly appealing to researchers, such as their ease of synthetic tunability, generally low toxicity, and high solubility in biological media in comparison to other NIR- and SWIR-emissive fluorophores. Different molecular skeletons have been examined for use as the core of these imaging agents, such as squaraine, cyanine, and …

Evaluation Of Promising Eco-Friendly Flame Retardants For Bio-Based Rigid Polyurethane Foams Based On Modified Castor Oil, Prasadi Abeysinghe Arachchilage

Electronic Theses & Dissertations

Fossil fuel derivatives in the polyurethane industry are gradually being replaced with environmentally friendly alternative bio-based resources. Vegetable-oil-based polyols are emerging bio-based resources that can decrease cost competitiveness in polyurethane markets, reduce environmental impacts, and meet the urgent need for green and sustainable development strategies. Among this, interest is the use of castor oil to make polyurethane because of its inedibility and the fact that it contains many functionalizable chemical groups. However, the poor thermal stability and low load-bearing capacity of castor-oil-based rigid polyurethane foam limits its application. Two methods were used to address these limitations: (i) more hydroxyl groups …

Design And Synthesis Of Dinucleating Phthalazine-Based Ligands Toward Bimetallic Ruthenium Catalysts For Water Oxidation, Alex Bromley

Honors Theses

Two synthetic pathways were developed to construct dinucleating ligands towards the synthesis of bimetallic ruthenium-based water oxidation catalysts. The motivation for this work stems from earlier observations of related ligands that are susceptible to oxidative decomposition. The design pursued here incorporates a phthalazine core into the dinucleating ligand, which, we hypothesize, will prevent the previously established cleavage of a pyridazine unit at the same position. The ligand precursors involved in the multi-step syntheses are characterized by Nuclear Magnetic Resonance (NMR) spectroscopy. Synthetic protocols were refined to ensure reproducibility. In addition, our hypothesis for which of the two target ligands will …

Isolating The Electronic Effects Of Systematic Twist In Highly Substituted Aromatic Hydrocarbons Using Density Functional Theory, Grace Tully, Emily A. Jarvis

Honors Thesis

Density functional theory (DFT) was employed to investigate dodecaphenyltetracene as well as similar molecules containing differing backbone lengths and electron withdrawing groups with interest in manipulating the twist to lower the LUMO level for increased electron mobility. Optimization and frequency time-independent calculations followed by time-dependent (TD-DFT) energy calculations were performed at the B3LYP/G-311G level of theory to analyze electronic trends as a result of increased backbone length and consequently distorted end-to-end molecular twist. These calculations demonstrate a linear relationship with negative slope between the estimated HOMO-LUMO, fundamental, and optical gaps as a function of the number of fused rings along …

Mechanisms Of Formation Of Novel Guanine-Guanine Cross-Links As Major End Products During One-Electron Oxidation Of Guanine Derivatives, Evan Dunn

Undergraduate Honors Theses

Guanine (G), as the most oxidizable base in DNA, is the major focus of studies of oxidation damage to DNA. The present thesis reports the first detailed characterization of G dimerization products potentially resulting from recombination of neutral G• radicals. Previous research has discovered a novel type of products of G• dimerization, D1 and D2, formed from one-electron oxidation of G derivatives. However, the mechanism of this dimerization remains elusive. While there appears to be a tautomeric equilibrium between two forms of G•, G(N₁-H)• or G(N₂-H)•, it remains unclear which intermediate participates in the formation of …

Supramolecular Pi-Donor/Acceptor Arrays Based On Redox-Active Metal-Organic Coordination Assemblies, Paola Benavides

All Dissertations

Coordination-driven self-assembly is an attractive strategy for constructing thermodynamically stable supramolecular coordination complexes, ranging from discrete metallacycles and cages to infinite coordination polymers and metal-organic frameworks for a variety of applications.

Chapter 1 discusses strategies for preparing supramolecular charge-transfer π-donor/acceptor assemblies and their potential applications.

Chapter 2 demonstrates that tricomponent self-assembly method, which was believed to yield 3D-cages, based on tetrapyridyl porphyrin (M’TPP, M’ = Zn or H₂), dicarboxylate ligands (XDC), and caped cis-Pt(II) corners, actually yields 2D-bowties featuring an M’TPP core and two parallel XDC linkers held together by four heteroligated PtII(N,O) corners. The 2D-bowties showed …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Synthesis Of A Phenyl Substituted Zinc Dipyrrin Complex For The Purpose Of Analyzing Aromatic Substitutions On The Characteristics Of Compounds Of This Class, Kole Owen

Undergraduate Honors Theses

The field of photochemistry is as innovative in development as it is broad in application. However, utilization of energy from the sun’s electromagnetic radiation remains secondary to the combustion of fossil fuels for the global energy consumption. This is neither a sustainable nor renewable system, and it has contributed to a major decline in the health of our global environment as the greenhouse gases emission has led to an incline in global temperatures and ocean acidity. To develop effective ways to utilize solar energy, experimental effort is being directed towards the understanding of photosensitizers, molecules which absorb solar radiation and …

The Effects Of Prior Calculus Classes On Success In Organic Chemistry, Tori Williamson

Theses/Capstones/Creative Projects

Within University of Nebraska – Omaha (UNO) chemistry-based degree programs, organic chemistry along with at least two semesters of calculus are required courses. There is, however, no requirement for the order in which these courses should be taken. This is mainly due to the notion that for chemistry courses, organic chemistry is detached from the typical quantitative concepts studied in other chemistry-based courses. This is untrue, however, as many organic chemistry concepts rely on three-dimensional spatial visualizations and manipulations. Spatial awareness skills are strengthened within higher-level calculus classes. A survey was administered to organic chemistry students enrolled in 2022-2023. The …

Separation Of Organic Acids Through Direct Catalysis From Sugars, Katelyn Robinson

Chemical Engineering Undergraduate Honors Theses

Society relies on plastic products, whether they are single use or durable. A downside of plastic is that the most common type is a product of oil and oil is not only a limited resource but also a climate-damaging resource. Polylactic acid (PLA) is a bio-based, biodegradable plastic. However, the process of converting biomass to polylactic acid polymer has the largest environmental impact of the PLA production process, so alternative methods of conversion are needed (Moretti et al., 2021). The polylactic acid polymer can be made with lactic acid, which can be converted from glucose.

Separating The R Vs. S Enantiomers Of A Quinoline Aimed At Inhibiting The Allosteric Binding Pocket Of Hiv-1 Integrase, Madison Canfield

Honors Theses

HIV-1 is a retroviral disease that infects CD4+ T cells in the body. Once inside the body, HIV-1 uses human cell machinery to replicate and reproduce using several enzymes to reverse transcribe viral RNA to DNA and integrate the viral DNA into the human genome to reproduce. Several drugs, such as NRTIs, INSTIs, NNRTIs, and PIs, have been created to inhibit specific parts of the viral life cycle and are used in combination to fight HIV-1. However, these medications face challenges of viral mutation and resistance, which increases the importance of creating more potent and effective drugs. Recently, a new …

Separating The R Vs. S Enantiomers Of A Quinoline Aimed At Inhibiting The Allosteric Binding Pocket Of Hiv-1 Integrase, Madison Canfield

Honors Theses

HIV-1 is a retroviral disease that infects CD4+ T cells in the body. Once inside the body, HIV-1 uses human cell machinery to replicate and reproduce using several enzymes to reverse transcribe viral RNA to DNA and integrate the viral DNA into the human genome to reproduce. Several drugs, such as NRTIs, INSTIs, NNRTIs, and PIs, have been created to inhibit specific parts of the viral life cycle and are used in combination to fight HIV-1. However, these medications face challenges of viral mutation and resistance, which increases the importance of creating more potent and effective drugs. Recently, a new …