Chemistry Commons^™

Spontaneous Transfer Of Chirality In An Atropisomerically Enriched Two-Axis System, K. T. Barrett, A. J. Metrano, Paul R. Rablen, S. J. Miller

Chemistry & Biochemistry Faculty Works

One of the most well-recognized stereogenic elements in a chiral molecule is an sp(3)-hybridized carbon atom that is connected to four different substituents. Axes of chirality can also exist about bonds with hindered barriers of rotation; molecules containing such axes are known as atropisomers(1). Understanding the dynamics of these systems can be useful, for example, in the design of single-atropisomer drugs(2) or molecular switches and motors(3). For molecules that exhibit a single axis of chirality, rotation about that axis leads to racemization as the system reaches equilibrium. Here we report a two-axis system for which an enantioselective reaction produces four …

Porphyrin Cross-Linkers For Generating Soluble Molecularly Imprinted Polymers From Polyethyleneimine, Mohammed R. Elshaer

Seton Hall University Dissertations and Theses (ETDs)

Molecular recognition is vital to many biochemical processes and is at the heart of promising bio-medically related technologies. Molecular imprinting has a long-standing history as a successful method for mimicking the molecular recognition phenomena exhibited by nature, whereby artificial receptors are prepared for a given target molecule based on synthetic polymers. The molecularly imprinted polymer (MIP) contains a three dimensional network with a memorized cavity specific to the shape and functionality of the templated target molecule. The utility of traditional MIPs has been limited due to an inherent lack of solubility. We have worked toward developing a system that allows …

Amino Acid Methyl Ester Chiral Ionic Liquids: A Concentration Study, Christopher J. Brown

Undergraduate Honors Thesis Collection

This project will investigate novel amino acid methyl ester chiral ionic liquids and determine how increased concentration of lanthanide solute and changes in size of counter ions tetramethylammonium and tetrabutylammonium affects interaction between the ionic liquid and the fluorescent lanthanide solute. Both concentration dependence and temperature dependence were discovered. The chiral ionic liquid [L-prolineCl][TfiN] reacted uniquely to the change in concentration.

Redox Active Motifs In Selenoproteins, Fei Li, Yuliya Pepelyayeva, Elias S. J. Arner, Craig A. Bayse, Sharon Rozovsky

Chemistry & Biochemistry Faculty Publications

Selenoproteins use the rare amino acid selenocysteine (Sec) to act as the first line of defense against oxidants, which are linked to aging, cancer, and neurodegenerative diseases. Many selenoproteins are oxidoreductases in which the reactive Sec is connected to a neighboring Cys and able to form a ring. These Sec-containing redox motifs govern much of the reactivity of selenoproteins. To study their fundamental properties, we have used Se-77 NMR spectroscopy in concert with theoretical calculations to determine the conformational preferences and mobility of representative motifs. This use of Se-77 as a probe enables the direct recording of the properties of …

Functionalization Of Silica Surface Using Chan-Lam Coupling, George Appiah Kubi

Electronic Theses and Dissertations

The reaction of base-free Chan-Lam coupling was successfully used for functionalization of surface of mesoporous silica gel. Various aromatic, aliphatic, and heterocyclic compounds were immobilized by a copper-catalyzed reaction of corresponding boronic acids with surface amino groups at mild conditions. Obtained functionalized materials were mesoporous although their surface area decreased after immobilization. The reactivity of some surface functional groups was tested in their characteristic reactions.

Synthesis Of A 4-(Trifluoromethyl)-2-Diazonium Perfluoroalkyl Benzenesuflonylimide (Pfsi) Zwitterionic Monomer For Proton Exchange Membrane Fuel Cell, Chimaroke Nworie

Electronic Theses and Dissertations

In order to achieve a more stable and highly proton conducting membrane that is also cost effective, the perfluoroalkyl benzenesulfonylimides (PFSI) polymers are proposed as electrolyte for Proton Exchange Membrane Fuel Cells. 4-(trifluoromethyl)-2-diazonium perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide (I) is synthesized from Nafion monomer via a 5-step schematic reaction at optimal reaction conditions. This diazonium PFSI zwitterionic monomer can be further subjected to polymerization. The loss of the diazonium N₂⁺ functional group in the monomer is believed to form the covalent bond between the PFSI polymer electrolyte and carbon electrodes support. All the intermediates and final products …

Ring-Opening Polymerization Of Lactones And Lactides: An Organic Chemistry Lab Synthesis, Erin Wissler

Celebrating Scholarship & Creativity Day (2011-2017)

This project analyzed the ring opening chemistry of D, L- lactide, γ – butyrolactone, valerolactone, dodecalactone and caprolactone. Starting with each of the above monomers, Sn(Oct)2,SnCl2, Zn(acac)2, ZnCL2, and AlCl3 were used as catalysts in the polymerization process. Initiators included benzyl alcohol, 2-phenylethanol and 1-butanol. The results of each reaction were analyzed by 1H-NMR and IR spectroscopy and dynamic light scattering (DLS). The results were collated to determine the most promising candidates for a student project in the teaching laboratory.

Synthesis Of A Soluble Thiopheneanthrone Organic Semiconductor: Thiopheneanthrone-1-Thioglycoliccarboxylic Acid, Denise M. Page

Senior Honors Theses

Organic semiconductors are currently being researched for various uses, both electronic and biologic. They are less expensive than current inorganic semiconductors and do not require doping. They are useful in many areas including thin film transistors, photovoltaic cells, and Light Emitting Diodes (LED). However, synthesizing soluble organic semiconductors has been difficult. As a result, this study undertakes the synthesis of a specific organic semiconductor aiming at increased solubility following an adapted literature protocol. Tests for solubility, fluorescence, and conductivity potential will be used to assess the potential of this molecule as a semiconductor. Synthesis of anthraquinone-1,8-bisthioglycoliccarboxylic acid as an intermediate …

Photochemical Elimination Reactions That Proceed Via Triplet Excited State Electrocyclic Ring Closures, Himali Devika Jayasekara

Master's Theses (2009 -)

Cage compounds have become an important tool for the study of biological processes. The research focuses on new cage compounds that can unmask functional groups present in biologically important molecules such as proteins, peptides, and oligonucleosides. The project focuses on certain functional groups that are often difficult to release photochemically. These are the thiolate groups present in cysteine residues of proteins and peptides. Thiolate groups are fairly basic leaving groups, unlike the more labile groups such as the carboxylates that are present in proteins and peptides, or the phosphate groups present in nucleosides. The research takes advantage of the ability …

Fundamental Studies Of Protein Ionization For Improved Analysis By Electrospray Ionization Mass Spectrometry And Related Methods, Kevin A. Douglass

Dissertations

Mass spectrometry (MS) is an analytical technique in which a sample is converted to gas-phase ions that are subsequently separated and detected. It offers great speed, selectivity, and sensitivity during analysis, characteristics which have enabled it to become a leading method for the study of proteins. The applications of MS for these biologically significant macromolecules range from accurately determining identity and sequence to shedding light on post-translational modifications and protein-molecule interactions. As a first step towards analysis by MS, gas-phase protein ions must be formed. A common method for ionization is electrospray ionization (ESI), where a liquid sample including the …

Synthesis And Evaluation Of 3-Aryl-4(1h)-Quinolones As Orally Active Antimalarials: Overcoming Challenges In Solubility, Metabolism, And Bioavailability, Andrii Monastyrskyi

USF Tampa Graduate Theses and Dissertations

Infectious diseases are the second leading cause of deaths in the world with malaria being responsible for approximately the same amount of deaths as cancer in 2012. Despite the success in malaria prevention and control measures decreasing the disease mortality rate by 45% since 2000, the development of single-dose therapeutics with radical cure potential is required to completely eradicate this deadly disease. Targeting multiple stages of the malaria parasite is becoming a primary requirement for new candidates in antimalarial drug discovery and development. Recently, 4(1H)-pyridone, 4(1H)-quinolone, 1,2,3,4-tetrahydroacridone, and phenoxyethoxy-4(1H)-quinolone chemotypes have been shown to be antimalarials with blood stage activity, …

Mapping Posttranscriptional Regulation Of The Human Glycome Uncovers Microrna Defining The Glycocode, Praveen Agrawal, Tomasz Kurcon, Kanoelani T. Pilobello, John F. Rakus, Sujeethraj Koppolu, Zhongyin Liu, Bianca S. Batista, William S. Eng, Ku-Lung Hsu, Yaxuan Liang, Lara K. Maha

Chemistry Faculty Research

Cell surface glycans form a critical interface with the biological milieu, informing diverse processes from the inflammatory cascade to cellular migration. Assembly of discrete carbohydrate structures requires the coordinated activity of a repertoire of proteins, including glycosyltransferases and glycosidases. Little is known about the regulatory networks controlling this complex biosynthetic process. Recent work points to a role for microRNA (miRNA) in the regulation of specific glycan biosynthetic enzymes. Herein we take a unique systems-based approach to identify connections between miRNA and the glycome. By using our glycomic analysis platform, lectin microarrays, we identify glycosylation signatures in the NCI-60 cell panel …

Synergism Between Airborne Singlet Oxygen And A Trisubstituted Olefin Sulfonate For The Inactivation Of Bacteria, Rajib Choudhury, Alexander Greer

Publications and Research

The reactivity of a trisubstituted alkene surfactant (8-methylnon-7-ene-1 sulfonate, 1) to airborne singlet oxygen in a solution containing E. coli was examined. Surfactant 1 was prepared by a Strecker-type reaction of 9-bromo-2-methylnon-2-ene with sodium sulfite. Submicellar concentrations of 1 were used that reacted with singlet oxygen by an “ene” reaction to yield two hydroperoxides (7-hydroperoxy-8-methylnon-8-ene-1 sulfonate and (E)-8-hydroperoxy-8-methylnon-6-ene-1 sulfonate) in a 4:1 ratio. Exchanging the H₂O solution for D₂O where the lifetime of solution-phase singlet oxygen increases by 20-fold led to an ∼2-fold increase in the yield of hydroperoxides pointing to surface activity …

Thermal Denaturation Of Mycobacterium Tuberculosis Protein Rv0045c Monitored By Intrinsic Tryptophan Fluorescence, Lindsey Renee Drake

Undergraduate Honors Thesis Collection

The aim of my project was to use intrinsic tryptophan fluorescence to monitor the denaturation pathway of a protein, specifically the Mycobacterium tuberculosis enzyme Rv0045c. The larger scientific goal and inspiration for this honors thesis was to use the amino acid residues of a protein to map it's unfolding by thermal denaturation.

Hitting Pause On Organic Chemistry, Jenny B. Vu

Interdisciplinary STEM Teaching & Learning Conference (2012-2019) (Archived)

Written procedures for performing organic chemistry experiments are replaced by visual demonstrations that allow students to watch these videos at home and/ or in the laboratory. These previously recorded demonstrations allow students to watch, pause, and rewind the video to better understand laboratory techniques.

Big Horned, Juniper Harrower

The Transdisciplinary STEAM+ Journal

Tinta y tinto (Spanish for black ink and red wine)
Through a process of oxidation, reduction, and light manipulation, Juniper stains and colors paper with red wine and a rich black pigment made of the wild harvested mushroom Coprinopsis atramentaria.

Intramolecular Nitrogen Delivery For The Synthesis Of C-Glycosphingolipids. Application To The C-Glycoside Of The Immunostimulant Krn7000, Ahmad Sabri Altiti, David R. Mootoo

Publications and Research

The key reaction in this approach to C-glycosphingolipids is the stereoselective iodocyclization of a sugar-linked homoallylic carbonimidothioate. E and Z reaction substrates were assembled in a convergent fashion via an alkene metathesis strategy and exhibited the same alkene facial selectivity in the iodocyclization irrespective of alkene geometry, although the E alkene was found to be less reactive.

The [4+2] Cycloaddition Of Donor-Acceptor Cyclobutanes And Nitrosoarenes., Naresh Vemula, Andrew C Stevens, Tyler B Schon, Brian L Pagenkopf

Chemistry Publications

The Yb(OTf)3 catalyzed [4+2] cycloaddition between donor-acceptor cyclobutanes and nitrosoarenes is disclosed. This method facilitates the synthesis of tetrahydro-1,2-oxazines in good to excellent yields as single diastereomers. Except for a few electron-deficient nitrosoarenes, excellent regioselectivity was observed throughout these studies.

Nickel-Catalyzed Cross-Coupling Reactions Involving Secondary And Tertiary Alkyl Nucleophiles, Amruta Ajit Joshi

Dissertations, Theses, and Capstone Projects

In the first chapter, introduction of transition metal-catalyzed cross-coupling reactions has been given. These transition metal-catalyzed C-C bond forming reactions have been used extensively in organic synthesis. Among them, C(sp2)-C(sp2) bond forming reactions have been widely studied over decades. More recently, some reports have demonstrated the use of C(sp3) nucleophiles and electrophiles in cross-coupling reactions. However, use of secondary and tertiary alkyl nucleophiles has remained a challenge due to competitive β-hydride elimination and slow transmetallation of bulky secondary and tertiary alkyl organometallic nucleophiles.

In the second chapter, the first general nickel-catalyzed Negishi reaction for the cross-coupling of unactivated, acyclic secondary …

Studies In Asymmetric Synthesis: Supramolecular Catalysis, C–H Activation, And D-Cycloserine Synthesis, Nathan C. Thacker

Department of Chemistry: Dissertations, Theses, and Student Research

Rh-catalyzed asymmetric hydrogenation has emerged as a powerful tool for the manufacturing of chiral pharmaceuticals. While the mechanism is well understood, catalyst design a priori is not yet possible. Supramolecular catalysis, the use of non-covalent forces to affect a catalytic process, can afford the catalyst diversity required to uncover efficient catalysts and further our understanding. Using a modular design and self-assembly, a large scale supramolecular catalyst screening in a catalyst scaffold optimization study of rhodium-catalyzed asymmetric hydrogenation was carried out. Analyzing the data yields some new insights into the roles of each module making up the supramolecular catalyst. Perhaps most …

Cyclic Phosphonium Ionic Liquids, Sharon I. Lall-Ramnarine, Joshua A. Mukhlall, James F. Wishart, Robert R. Engel, Alicia R. Romeo, Masao Gohdo, Sharon Ramati, Marc B. Berman, Sophia N. Suarez

Publications and Research

Ionic liquids (ILs) incorporating cyclic phosphonium cations are a novel category of materials. We report here on the synthesis and characterization of four new cyclic phosphonium bis(trifluoromethylsulfonyl)amide ILs with aliphatic and aromatic pendant groups. In addition to the syntheses of these novel materials, we report on a comparison of their properties with their ammonium congeners. These exemplars are slightly less conductive and have slightly smaller self-diffusion coefficients than their cyclic ammonium congeners.

Br[O/]Nsted Acid Catalyzed Asymmetric Allylation And Propargylation Of Aldehydes, Pankaj Jain

USF Tampa Graduate Theses and Dissertations

Carbonyl allylation and propargylation reactions have been an important tool for the stereocontrolled formation of carbon-carbon bonds for synthetic chemists. The chiral homoallylic and homopropargylic alcohols obtained from these reactions serve as versatile intermediates for the synthesis of natural and pharmaceutical products. Over the past three decades and continuing on, various synthetic groups around the globe have directed their research towards the efficient synthesis of these chiral moieties. In spite extensive research, asymmetric allylation and propargylation reactions remain an enduring challenge in organic chemistry.

Chapter 1 of this thesis describes the first phosphoric acid catalyzed asymmetric allylboration of aldehydes. We …

Spectral Data For "Probing The Human Estrogen Receptor-Alpha Binding Requirements For Phenolic Mono- And Do-Hydroxyl Compounds: A Combined Synthesis, Binding And Docking Study", Christopher Mccullough, Terrence S. Neumann, Jayapal Reddy Gone, Zhengjie He, Julie Lukesh, Rajesh K. Pandey, William A. Donaldson, Daniel S. Sem

Natural Products Synthesis via Organoiron Methodology

Spectral data used in the course of researching "Probing the human estrogen receptor-alpha binding requirements for phenolic mono- and do-hydroxyl compounds: A combined synthesis, binding and docking study".

Various estrogen analogs were synthesized and tested for binding to human ERα using a fluorescence polarization displacement assay. Binding affinity and orientation were also predicted using docking calculations. Docking was able to accurately predict relative binding affinity and orientation for estradiol, but only if a tightly bound water molecule bridging Arg394/Glu353 is present. Di-hydroxyl compounds sometimes bind in two orientations, which are flipped in terms of relative positioning of their hydroxyl groups. …

A New Methodology For The Synthesis Of 2-Alkyl-5,6-Bis(Alkylthio)Benzo[D]Thiazole-4,7-Dione, Jeena Foronda

Capstone Research Projects

Cancer is a rapidly growing fatal disease and with the various thiazole compounds being scientifically generated, possible treatment options can be implemented. Proper synthesis of 2,3-dimethoxy-1,4-benzoquinone allows for a variety of compounds to be made with further treatment of alkylthio reagents. Both thioacetamide and thiobenzamide are used to react with 2,3-dimethoxy-1,4-benzoquinone in order to build a library of thiazoles. Final compounds can be tested for the ability to inhibit recombinant enzyme activity and the capability to kill tumor cells. A basic oxidation procedure along with nucleophilic attack was used to create target products.

New Carbohydrate-Based Anti-Cancer And Anti-Bacterial Vaccines, Zhifang Zhou

Wayne State University Dissertations

The unique carbohydrates expressed on the surface of cancer, bacterial, viral and fungal cells are excellent target antigens for the design of therapeutic or preventive vaccines. However, as antigens carbohydrates have problems. First, carbohydrates usually have low immunogenicity. Second, even if immunogenic, carbohydrates typically elicit T cell-independent immune responses. To overcome these problems and design useful vaccines based on carbohydrate antigens, they are usually coupled with carrier proteins to form conjugates to enhance the immunogenicity of the antigens. However, there are still some issues existing in glycoprotein vaccines, such as poor reproducibility of the conjugates, difficulties in quality control and …

Deuterium Tracer Study Of The Mechanism Of Iron Catalyzed Fischer-Tropsch Synthesis, Yunxin Liao

Online Theses and Dissertations

The Fischer-Tropsch Synthesis (FTS) was invented in 1920s, shortly after its invention, it became an important way to produce synthetic fuels. The FTS is also an important way to understand the origin of life. Even though the FTS has been used to produce liquid fuels commercially for a relatively long time, the mechanism of FTS is still unclear, a mechanism can explain all the experimental observations has not been discovered yet.

By conducting H2/D2 switching experiments we found that there was an inverse isotope effect in the Fe catalyzed FTS. The rate of hydrocarbon production was increased when syngas H2/CO …

Water Purification Through Ion Exchange, Brittany Webb

Natural Sciences Student Research Presentations

Water purification through ion exchange is the process of removing undesired contaminates from water through the exchange of ions between two electrolytes. Clinoptilolite is used as an exchange site.

Basic Features Of A Cell Electroporation Model: Illustrative Behavior For Two Very Different Pulses, Reuben S. Son, Kyle C. Smith, Thiruvallur R. Gowrishankar, P. Thomas Vernier, James C. Weaver

Bioelectrics Publications

Science increasingly involves complex modeling. Here we describe a model for cell electroporation in which membrane properties are dynamically modified by poration. Spatial scales range from cell membrane thickness (5 nm) to a typical mammalian cell radius (10 μm), and can be used with idealized and experimental pulse waveforms. The model consists of traditional passive components and additional active components representing nonequilibrium processes. Model responses include measurable quantities: transmembrane voltage, membrane electrical conductance, and solute transport rates and amounts for the representative "long" and "short" pulses. The long pulse-1.5 kV/cm, 100 μs-evolves two pore subpopulations with a valley at ~5 …

Spectroscopic Characterization Of Dissolved Organic Matter: Insights Into The Linkage Between Sources And Chemical Composition, Xiaoyan Cao

Chemistry & Biochemistry Theses & Dissertations

This dissertation investigated the chemical structure of DOM by advanced solid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) techniques, as well as isotopic measurements and UV-visible spectroscopy, to shed light on the linkages between DOM sources and DOM composition. Unique and extensive sets of DOM samples studied here were isolated from various aquatic systems, covering end-member environments in which DOM is considered either microbially derived or terrestrially derived, and areas in which DOM has characteristics intermediate between the two end members. Important insights into specific site-related questions were also gained such as …

Synthesis And Characterization Of Sugar Based Low Molecular Weight Gelators And The Preparation Of Chiral Sulfinamides, Hari Prasad Reddy Mangunuru

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) have received considerable attention in the field of chemistry from last few decades. These compounds form self-assembled fibrous networks like micelles, cylindrical, sheets, fibers, layers and so on. The fibrous network entraps the solvent and forms gel, because of the self-assembly phenomenon and their demonstrated potential uses in a variety of areas, ranging from environmental to medicinal applications.

Sugars are good starting materials to synthesize the new class of LMWG's, because these are different from some expensive materials, these are natural products. We have synthesized and characterized the LMGS's based on D-glucose and D …