Brønsted Acid Catalyzed Carbon-Carbon Bond Forming Reactions,
2018
University of Denver
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 …
Selective Carbon-Carbon Bond Formation Promoted By Divalent Samarium Reagents,
2018
University of Denver
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 …
Experiential Learning Activity: Biodiesel Inquiry Project,
2018
CUNY Guttman Community College
Experiential Learning Activity: Biodiesel Inquiry Project, Ji Kim
Open Educational Resources
The activity described herein can be implemented in introductory chemistry and high school chemistry courses. The main goal of the project is to integrate a ubiquitous biodiesel production with experiential learning by providing a community-based project. The students work in groups, research the benefits of using biodiesel over petroleum-based diesel, collect waste cooking oil from home or restaurants, develop simple and cost-effective methods to produce biodiesel.
The Scientific Contributions Of Donald J. Cram,
2018
Parkland College
The Scientific Contributions Of Donald J. Cram, Leiah Carney
Natural Sciences Student Research Presentations
This poster for the Natural Sciences Poster Session summarizes the work of Donald J. Cram in the field of organic chemistry. A Nobel prizewinner in 1987, he is known for his work with hemicarcerands and carcerands, molecular containers which aided in the study of unstable molecules.
Cation Clock Reactions For The Determination Of Relative Reaction Kinetics In Glycosylation Reactions,
2018
Wayne State University
Cation Clock Reactions For The Determination Of Relative Reaction Kinetics In Glycosylation Reactions, Philip Adero
Wayne State University Dissertations
This dissertation presents the development of cyclization reactions as clocks for the determination of the molecularity of glycosylation reactions in individual pyranoside systems and extends it to the arabinofuranoside systems. It also describes the development of selective hydrogenolytic cleavage of naphthylmethyl ethers in the presence of sulfides.
The first part of chapter one gives an overview of the significance of glycochemistry and the challenges involved. The second part describes some selected glycosylation methods and extends this to the general mechanistic studies of glycosylation. This is followed by the discussion of the general clock reactions in literature which initiates a further …
Design And Synthesis Of Oligo-(3,5-Dithio-Β-D-Glucopyranoside) As Β-(1→3)-Glucan Mimetics,
2018
Wayne State University
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 …
Design Of Ruthenium(Ii) Polypyridyl Complexes For Effectively Caging Nitriles And Aromatic Heterocycles,
2018
Wayne State University
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 …
Modification Of 4,5- Aminoglycosides To Overcome Drug Resistance Bacteria And Toxic Side Effect,
2018
Wayne State University
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 …
Environmental Forensics Study Of Crude Oil And Petroleum Product Spills In Coastal And Oilfield Settings: Combined Insights From Conventional Gc-Ms, Thermodesorption-Gc-Ms And Pyrolysis-Gc-Ms,
2018
University of Oviedo
Environmental Forensics Study Of Crude Oil And Petroleum Product Spills In Coastal And Oilfield Settings: Combined Insights From Conventional Gc-Ms, Thermodesorption-Gc-Ms And Pyrolysis-Gc-Ms, Michael A. Kruge, José Luis Gallego, Azucena Lara-Gonzalo, Noemi Esquinas
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
A representative set of five oil spill samples from four different regions displayed different product characteristics and different levels of weathering. Three of them were taken along shorelines affected by marine oil spill events, viz., Aboño and Prestige (Spain) and Deepwater Horizon (USA) and the other two were taken at inland oil spill sites (Angola and Kuwait). A multi-faceted environmental forensics approach revealed key molecular features. In addition to the conventional GC/MS analysis of saturated and aromatic fractions, the polar fractions also were analyzed, revealing a complex series of linear alkanones in those oil samples particularly enriched in aliphatics. Thermodesorption-GC-MS …
Progress Toward Controlled Disulfide Formation To Access Neuroactive Conotoxins,
2018
Wayne State University
Progress Toward Controlled Disulfide Formation To Access Neuroactive Conotoxins, Thilini Kondasinghe
Wayne State University Dissertations
"Conotoxins are mini proteins isolated from marine snails of the Conus family. They have shown activity in the selective inhibition of various ion channels. Therefore, they present an opportunity as possible therapy for a myriad of neurological ailments. The synthesis of conotoxins would enable both biological studies and evaluation of these structures as lead targets for therapeutics. However, establishing a reliable method to consistently folding disulfide rich proteins, including conotoxin, into their native structure has been challenging over few decades. In this research project, it is shown the progress towards a mild, efficient, and broadly applicable methods to generate the …
Investigation Of Volatile Organic Compounds (Vocs) Detected At Vapor Intrusion Sites,
2018
University of Kentucky
Investigation Of Volatile Organic Compounds (Vocs) Detected At Vapor Intrusion Sites, Mohammadyousef Roghani
Theses and Dissertations--Civil Engineering
This dissertation investigates unexplained vapor intrusion field data sets that have been observed at hazardous waste sites, including: 1) non-linear soil gas concentration trends between the VOC source (i.e. contaminated groundwater plume) and the ground surface; and, 2) alternative pathways that serve as entry points for vapors to infiltrate into buildings and serve to increase VOC exposure risks as compared to the classic vapor intrusion model, which primarily considered foundation cracks as the route for vapor entry. The overall hypothesis of this research is that theoretical knowledge of fate and transport processes can be systematically applied to vapor intrusion field …
Molecular Level Encapsulation Of Chromophores Using Pillar[5]Arenes For Enhanced Photostability,
2018
South Dakota State University
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 …
Characterizing Glucose Tolerance In Adult Lew.1wr1 Rats,
2018
University of Alabama in Huntsville
Characterizing Glucose Tolerance In Adult Lew.1wr1 Rats, Luis Mercado, Genoah Collins, Amelia Clopp
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Fast Isotope Ratio Mass Spectrometry (Firms): A Tandem Mass Spectrometry Technique For The Rapid And Semi-Comprehensive Evaluation Of Isotope Ratios,
2018
South Dakota State University
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) …
Addressing The Threat Of Multidrug Resistant Infectious Diseases By Synthesis Of Novel Aminoglycoside Antibiotics,
2018
Wayne State University
Addressing The Threat Of Multidrug Resistant Infectious Diseases By Synthesis Of Novel Aminoglycoside Antibiotics, Girish Chandra Sati
Wayne State University Dissertations
The ever-growing increase in multidrug resistant infectious diseases is one of the major cause of human mortality, and there is an inherent need for the development of new antibiotics. Since the discovery of streptomycin, AGAs have been playing a very important role in human therapy as highly potent broad-spectrum antibiotics and are listed as one of the critically important antimicrobials by WHO. AGAs act by inhibiting the bacterial protein synthesis and by targeting the A-site present in the small subunit of bacterial ribosome. The clinical use of AGAs is somewhat restricted due to their toxic effects (ototoxicity and nephrotoxicity) and …
Palladium-Catalyzed Carbonyl Allylation Reactions Using Tin Chloride: A Mini-Review,
2018
Ateneo de Manila University
Palladium-Catalyzed Carbonyl Allylation Reactions Using Tin Chloride: A Mini-Review, Armando M. Guidote Jr, Mikael John A. Baltazar, Roy Kristian C. Yanela, Noriyuki Suzuki
Chemistry Faculty Publications
The treatment of allylic alcohols as synthons of carbanions for carbonyl allylation reactions in the presence of a Pd-SnCl2 system has been one of the most interesting and most useful developments demonstrated by Yoshiro Masuyama and co-workers in the field of organic synthesis. The reaction makes use of palladium as an effective catalyst and tin (II) chloride as a low-valent reducing agent which also effectively transforms the allylic group to a nucleophilic group. The organic, as well as organometallic, chemistry of how the transformations occur and how the metals take part in the reaction is of great interest. These could …
Stereoselective Synthesis Of Legionaminic Acid And Pseudaminic Acid Glycosides,
2018
Wayne State University
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 …
Richard Smalley And The Materials Of Tomorrow: The Discovery And Science Of Fullerenes,
2018
Parkland College
Richard Smalley And The Materials Of Tomorrow: The Discovery And Science Of Fullerenes, Creighton A. Jackson
Natural Sciences Student Research Presentations
This poster for the Natural Sciences Poster Session at Parkland College details the contributions of Richard Smalley to organic chemistry, specifically the discovery of fullerenes in 1984, which led to advancements in the field of nanoscience. Fullerene use in materials science, Single-walled and multi-walled nanotubes and use of fullerenes in biology are also outlined.
Lignin Depolymerization: Mechanistic Analysis, Optimization And Application,
2018
South Dakota State University
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, …
Silicon And Tin Substituted Halocyclopropanes: Approaches To New Carbenes And Strained Cyclic Allenes,
2018
Colby College
Silicon And Tin Substituted Halocyclopropanes: Approaches To New Carbenes And Strained Cyclic Allenes, Noura Srour
Honors Theses
Chloro(trimethylsilyl)carbene and chloro(trimethylstannyl)carbene were generated through photolysis of cyclopropanated phenanthrene precursors which were synthesized in two steps. The photolysis reactions were done in the presence of cis and/or trans-beta-methylstyrene. Though product peaks corresponding to the carbene-alkene adducts were observed in the GCMS, the yields were too low for their isolation and complete characterization. Density functional theory (DFT) calculations were performed on the stereoisomers of the precursor to Chloro(trimethylsilyl)carbene and the carbene itself. Surprisingly, Chloro(trimethylsilyl)carbene’s triplet state was found to be more stable than the singlet at this level of theory.
In a related project, (1-bromo-1a,9b-dihydro-1H-cyclopropa[l]phenanthren-1-yl)trimethylstannane, was …
