Organic Chemistry Commons^™

Design Of Ruthenium(Ii) Polypyridyl Complexes For Effectively Caging Nitriles And Aromatic Heterocycles, Ao Li

Wayne State University Dissertations

ABSTRACT

DESIGN OF RUTHENIUM(II) POLYPYRIDYL COMPLEXES FOR EFFECTIVELY CAGING NITRILES

AND AROMATIC HETEROCYCLES

by

AO LI

May 2018

Advisor: Dr. Jeremy Kodanko

Major: Chemistry

Degree: Doctor of Philosophy

Ru(II) polypyridyl complexes have been frequently employed in the caging and photorelease of biologically active compounds. Traditional photocaging groups derived from Ru(II) have been largely based on bi- or tridentate ancillary ligands, and those bearing ancillary ligands with high-denticities are yet to be developed. Exploring Ru(II) polypyridyl complexes possessing ancillary ligands with high-denticities provides insight into the photophysical and photochemical properties of ruthenium complexes, which creates novel prospects in the design of …

Design And Synthesis Of Oligo-(3,5-Dithio-Β-D-Glucopyranoside) As Β-(1→3)-Glucan Mimetics, Xiaoxiao Liao

Wayne State University Dissertations

This dissertation presents the design and synthesis of oligo-(3,5-dithio-β-D-glucopyranoside) as β-(1 → 3)-D-glucan mimetics. The synthesized dimeric, trimeric and tetrameric mimetics were tested for their binding affinities to Dectin-1 and CR3 and their abilities to activate phagocytosis and pinocytosis.

The first chapter gives an introduction of β-(1 → 3)-D-glucan. It gives an introduction about the structure and origin of β-(1 → 3)-D-glucan as well as the immunostimulating effect of natural β-(1 → 3)-D-glucan. The study of interaction between β-(1 → 3)-D-glucan and the receptors leads to a conclusion that the hydrophobicity of β-(1 → 3)-D-glucan is crucial to its immunostimulating …

Modification Of 4,5- Aminoglycosides To Overcome Drug Resistance Bacteria And Toxic Side Effect, Guanyu Yang

Wayne State University Dissertations

ABSTRACT

MODIFICATION OF 4,5- AMINOGLYCOSIDES TO OVERCOME DRUG RESISTANCE BACTERIA AND TOXIC SIDE EFFECT

by

Guanyu Yang

September 2018

Advisor: Professor David Crich

Major: Chemistry

Degree: Doctor of Philosophy

Infectious diseases causing by antibiotic resistant pathogen are one of the major threat to human health and society today. Many researchers tried to develop next generation of antibiotics by reinvesting the existing antibacterial drugs. Aminoglycosides have long been used as highly potent and broad-spectrum antibiotics for treating bacterial infections. But their side effect, especially the irreversible ototoxicity, and the fast-growing resistant problem limit their application. The goal of this research was …

Stereoselective Synthesis Of Legionaminic Acid And Pseudaminic Acid Glycosides, Bibek Dhakal

Wayne State University Dissertations

Legionaminic acid (Leg) and pseudaminic acid (Pse) are deoxy acetamido analogues of the most common sialic acid, N-acetylneuraminic acid (NeuAc) that are found in microorganisms. Leg and Pse are rare but important class of sialic acids, as their glycosides are found in lipopolysaccharides and glycoproteins of several pathogenic Gram-negative bacteria including Pseudomonas aeruginosa, Legionella pneumophila serogroup 1, Campylobacter jejuni, and Campylobacter coli. As such, the stereoselective glycosylation of the equatorial Leg and Pse donors, and the role played by their side chain conformations in anomeric reactivity and selectivity are the focus of this thesis.

Chapter two describes the synthesis of …

Fast Isotope Ratio Mass Spectrometry (Firms): A Tandem Mass Spectrometry Technique For The Rapid And Semi-Comprehensive Evaluation Of Isotope Ratios, Fredrick Ochieng

Electronic Theses and Dissertations

Isotope ratios (IRs) are a measure of the variation in abundance of light isotopes versus heavy isotopes of an element, e.g. ¹H/²H,¹²C/¹³C, and ¹⁴N/¹⁵N. Because IRs change as a molecule undergoes certain chemical and physical processes, they represent unique fingerprints that can be used to trace the source of a chemical compound. Current techniques for determination of IRs each have major limitations, such as loss of structural information, vulnerability to contamination, high cost, large sample size requirements, low precision, limited applicability, and lengthy analysis. Fast Isotope Ratio Mass Spectrometry (FIRMS) …

Molecular Level Encapsulation Of Chromophores Using Pillar[5]Arenes For Enhanced Photostability, Manik Gudimani

Electronic Theses and Dissertations

Organic π-conjugated materials have been researched extensively for a number of applications including organic photovoltaics, electrooptic (EO) modulation, solid-state lasing, organic light emitting diodes (OLEDs), biological imaging and sensing, chemical sensing and ligands for photocatalysts. These organic optoelectronic materials have one major issue that affects its performance and lifetime—photostability. For some applications, hermetical packaging, which is expensive, is required to prevent degradation by light and oxygen. Photooxidation occurs when a material is exposed to light and causes structural and chemical changes leading to photodegradation of the material. The two primary degradation mechanisms responsible for photooxidation involve superoxide radical anion and …

Lignin Depolymerization: Mechanistic Analysis, Optimization And Application, Eric Michael Nagel

Electronic Theses and Dissertations

Lignin is the most abundant aromatic biopolymer and is a potential source for phenolic chemical feedstocks. Lignin is composed of phenolic units connected by more than eight different linkages, the most common being β-O-4 which constitutes 50-60%. The hydrothermal decomposition of a guaiacol based β-O-4 lignin dimer was studied under neutral and basic conditions to elucidate the mechanism of β-O-4 bond cleavage and the formation of downstream products. Phenol-carbonyl condensation and vinyl-ether formation were shown to be the primary causes for low monomer yields under the tested conditions. Three Ni catalyst systems, Ni/C + H₂, Ni/C-Zn, and Ni/Zn, …

Chalcone And Cinnamate Synthesis Via One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions Of Ketones And Acetate Esters, C. Wade Downey, Hadleigh M. Glist, Anna Takashima, Samuel R. Bottum, Grant J. Dixon

Chemistry Faculty Publications

Aryl alkyl ketones, acetate esters, and acetamides undergo facile one-pot enol silane formation, Mukaiyama aldol addition, and dehydrosilyloxylation in the presence of an amine base and excess trimethylsilyl trifluoromethanesulfonate. The chalcone and cinnamate products are generally recovered in high yield. The relative stoichiometry of the trimethylsilyl trifluoromethanesulfonate and amine base reagents determines whether the reaction yields the β- silyloxy carbonyl product or the α, β -unsaturated carbonyl.

One-Pot Enol Silane Formation-Alkylation Of Ketones With Propargyl Carboxylates Promoted By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Danielle N. Confair, Yiqi Liu, Elizabeth D. Heafner

Chemistry Faculty Publications

Ketones readily undergo conversion to enol silanes in the presence of trialkylamine base and trimethylsilyl trifluoromethanesulfonate (TMSOTf) and add to propargyl cations to yield b-alkynyl ketones. The propargyl cations are generated in the same reaction flask through the TMSOTf-promoted ionization of propargyl acetates or propargyl propionates. A range of enol silane precursors and propargyl carboxylates reacts efficiently (20 examples, up to 99% yield). Cyclization of a representative product in the presence of TMSOTf provided 61% yield of the trisubstituted furan.

Oxidation Of Β-O-4 Lignin Model Compounds And Application To Lignin Linkage Degradation Facilitated By Mechanochemical Treatment And Two-Step Oxidative Depolymerization, Soledad G. Yao

Theses and Dissertations--Chemistry

The oxidation of lignin model compounds was studied in conventional solvents in parallel with oxidations in ionic liquid solvents. Catalyst systems were investigated in ionic liquid solvents to determine how reaction rates and the selectivity for benzylic carbon oxidation were affected. Oxidation rates were often lower in ionic liquids than in conventional solvents ‒ as indicated by lower conversion in a standard reaction time ‒ likely due, at least in part, to the higher viscosity of ionic liquids. Mechano chemical treatment of Indulin AT kraft lignin by ball milling with KOH and toluene produced significant carbonyl functionality, among other changes. …

Study Of The Effect Of Steric Bulk Of Side Chains On The Properties Of Conjugated Polymers, Bei Zhang

Theses and Dissertations--Chemistry

Donor-acceptor conjugated polymers opened a new era for conjugated polymer research due to the abundant selection and combination of different conjugated units. This class of polymers function as semiconductor materials with potential application in plastic consumer electronics. The frontier molecular orbital energies of the polymers are generally determined by the selection of donor and acceptor units in the backbone structure, and their substituents. The side chains attached to the backbone not only affect the solubility of the materials, but also their self-assembly and morphological characteristics, which indirectly govern optoelectronic properties. It is important therefore to consider backbone architectures and the …

Selective Carbon-Carbon Bond Formation Promoted By Divalent Samarium Reagents, Christopher David-James Aretz

Electronic Theses and Dissertations

Three efficient methods for synthesis of five membered carbocycles, a highly understudied product motif in samarium(II) chemistry, were explored and optimized. These methods utilized simple starting materials to generate linear substrates with functional groups that are reactive towards samarium(II) iodide. The three methods explored were the Reformatsky-aldol, Reformatsky-alkylation, and pinacol cyclizations. The critical discovery for efficient formation of the Reformatsky-aldol and pinacol carbocycles products was the use of lithium bromide. This addition of lithium bromide facilitates easy in situ formation of samarium(II) bromide. The Reformatsky-alkylation cyclization was a newly realized reaction employing samarium enolates. Two of the three methods, the …

Brønsted Acid Catalyzed Carbon-Carbon Bond Forming Reactions, Jiangyue Miao

Electronic Theses and Dissertations

The focus of this research project lies in the development of new methodology in the field of Brønsted acid catalysis enabling rapid synthesis of medicinally relevant compounds. It is foreseen that small molecule sulfonic acids evaluated in this research project will unveil new asymmetric carbon carbon bond forming reactions between substrates hitherto unexplored with Brønsted acid catalysis. It has been established that strong Brønsted acids, such as phosphoric acids, are capable of mediating highly selective transformations operating through unique mechanistic manifolds.

Specific focus for the sulfonic acid catalysts was geared towards asymmetric coupling reactions with synthetically useful precursors such as …

Progress Towards The Synthesis Of Iron-Based Hydrogenation Catalysts Using Hydroxypyridine Bidentate And Tetradentate Ligands, Sara Rockow

Summer Research

This project aimed to develop tools to increase the sustainability of the pharmaceutical industry. The pharmaceutical industry is one of the largest global markets; and one of the most wasteful. Catalysis has been identified as a key tool in sustainable chemistry. One of the most important catalytic reactions in the pharmaceutical industry is the hydrogenation of carbonyl groups, which traditionally relies on transition metal complexes. These metals are environmentally harmful; this project focuses on synthesizing iron-based hydrogenation catalysts as benign alternatives. In order to form the catalysts, organic ligands need to be attached to iron precursors. Simpler model ligands were …

Synthesis And Catalytic Testing Of A Proline Functionalized Amphiphilic Block Copolymer, Eric Firestone

Master's Theses and Doctoral Dissertations

Catalysts are reagents used to reduce the amount of energy that a reaction needs to execute, allowing it to proceed at a higher rate while not being consumed. The use of catalyst functionalized amphiphilic copolymer allows easier recovery of the catalyst at the end of the synthesis and allows for the reaction. In water, under appropriate conditions, the amphiphilic block copolymers will form micelles and allow the reaction to occur on the interior of the micelle. The synthesis of amphiphilic copolymer with a hydrophobic O-methacryloyl-trans-4- hydroxy-L-proline and methyl methacrylate end and a hydrophilic acrylic acid end was characterized. The polymer …

Effect Of Curing Rate On The Microstructure And Macroscopic Properties Of Epoxy Fiberglass Composites, Ammar Patel, Olesksandr Kravchenko, Ica Manas-Zloczower

Mechanical & Aerospace Engineering Faculty Publications

Curing rates of an epoxy amine system were varied via different curing cycles, and glass-fiber epoxy composites were prepared using the same protocol, with the aim of investigating the correlation between microstructure and composite properties. It was found that the fast curing cycle resulted in a non-homogenous network, with a larger percentage of a softer phase. Homogenized composite properties, namely storage modulus and quasi-static intra-laminar shear strength, remained unaffected by the change in resin microstructure. However, fatigue tests revealed a significant reduction in fatigue life for composites cured at fast curing rates, while composites with curing cycles that allowed a …

Detection And Determination Of Food Residues In Native American Pottery, Katherine A. Plotzke

Honors Program Theses

The purpose of this research was to develop a new method of analyzing organic residues left on Native American pottery using linear Raman spectroscopy. Native American pottery was replicated using terra cotta and maple syrup was boiled in each of the pots using boiling stones. The pottery shards were then analyzed using Raman spectroscopy. Shards of pottery with maple syrup residue were compared to the standards and the syrup residue was not only detected, but also matched to compounds in the instrument library. Typically, the study of Native American pottery has been done in a variety of different ways, many …

An Interdisciplinary Approach To The Target Elucidation Of Novel Antibiotic 31g12, Larissa A. Walker

Graduate Student Theses, Dissertations, & Professional Papers

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in …

Synthesis Of New Bodipy Analogs, John Dilyard

Williams Honors College, Honors Research Projects

This report examines the synthesis of new ligands based upon dipyrazolylmethane and diindazolylmethane. The goal of these modifications is to increase the acidity of the proton on the methyl carbon to allow for deprotonation. The ligands synthesized were dipyrazolylphenylmethane and diindazolylphenylmethane, as well as modifications of the latter. The products were analyzed by NMR spectroscopy and one crystal structure was obtained of diindazolylphenylmethane.

Part I: Design, Synthesis, And Studies Of Novel Age-Inhibitors And Age-Breakers; Part Ii: Novel Synthetic Methods For Organofluorine Compound, Jatin Mehta

Doctoral Dissertations

"Novel small molecule inhibitors and breakers of advanced glycation end-products (AGEs) have been synthesized and their in vitro inhibitory activities have been studied by ¹³C NMR, fluorescence, and UV-visible spectroscopy. We have demonstrated that these AGE-inhibitors and AGE-breakers were found to be more effective in their sequestration of AGE intermediates, such as dehydroascorbate (DHA) than the state-of-the art phenacylthiazolium bromide (PTB)-based AGE-inhibitors and AGE-breakers. Citric acid and other polyphenolic antioxidants have substantial AGE inhibitory effects in the D-glucose/leucine or benzylamine Maillard reaction model systems, and thus they are suitable as dietary additives for ameliorating AGE-induced complications.

Organofluorine compounds have …