Organic Chemistry Commons^™

Chiral Phosphoric Acid-Catalyzed Acetalization And Iso-Pictet-Spengler Reactions, Matthew Jon Kaplan

USF Tampa Graduate Theses and Dissertations

The development of novel asymmetric reaction methodologies has been invaluable in both the academic and industrial world. In just 15 years, organocatalysis has provided a new means of developing asymmetric reaction methodologies using catalysts that are environmentally benign, relatively inexpensive, bench stable, and non-toxic. One development in organocatalysis that is important to our group in particular is chiral phosphoric acid-catalysis. BINOL-derived and VAPOL-derived phosphoric acids have proven to be excellent catalysts for a number of reactions.

The two projects I will discuss my efforts on are acetalization and iso-Pictet-Spengler reactions. These were projects that I performed during my first two …

Synthesis Of Amphiphilic Α- And Γ-Aapeptides For Antimicrobial, Self-Assembly, And Mineralization Studies, Mohamad N. Amin

USF Tampa Graduate Theses and Dissertations

Seven novel, amphiphilic AApeptides were prepared. Two cationic, lipo-α-AApeptides, NA-75 and NA-77 were found to possess potent antimicrobial activity against Gram-positive bacteria, with almost no hemolytic activity. In addition to NA-75 and 77, four amphiphilic, γ-AApeptides, NA-133, 135, 137, and 139, and one anionic lipo-α-AApeptide, NA-81, were prepared for molecular self-assembly studies, with several interesting nanostructures observed by TEM. Mineralization of calcium carbonate from gaseous CO2 and Ca2+ in the presence of the 7 AApeptide amphiphiles was also observed by optical microscopy. Several AApeptides were found to be able to influence CaCO3 crystal morphology. Another α-AApeptide, NA-63, was synthesized by …

Water-Soluble Deep-Cavity Cavitands: Synthesis, Molecular Recognition, And Interactions With Phospholipid Membranes, Sarah E. Ioup

LSU New Orleans Theses and Dissertations

Water-soluble deep-cavity cavitands provide a rare opportunity to study self-assembly driven by the hydrophobic effect. These molecular hosts dimerize in the presence of certain guest molecules to form water-soluble molecular capsules. These systems have given rise to numerous novel chemical phenomena and have potential use in drug delivery. The host octaacid (OA) has been particularly well-characterized, but studies are limited to basic pH because of limited host solubility.

Herein we report an improved synthesis of OA and the syntheses of three new water-soluble deep-cavity cavitands. The new hosts are soluble at neutral pH, increasing relevance for biological studies. The new …

Bf2obn∙Oet2: A Novel Lewis Acid And Its Use In A Regio- And Stereo-Selective Opening Of Trisubstituted Epoxides And Its Application Towards Amphidinolide C, Nicholas A. Morra, Brian Pagenkopf

Chemistry Publications

The generation of a new Lewis acid (BF2OBn·OEt2) has been reported, and its usefulness has been demonstrated in the regio- and stereoselective ring-opening of trisubstituted epoxides. This Lewis acid is one in a series of new Lewis acids generated from BF3·OEt2 that display varying levels of Lewis acidity. When paired with a modified Shi epoxidation protocol, highly functionalized propionate units, such as those found in a wide variety of natural products, can be accessed. In conjunction with a Mukaiyama oxidative cyclization employing our second generation catalyst Co(nmp)2, this procedure ultimately culminated in the shortest and highest yielding route towards the …

Phosphorus Transport And Distribution In Kentucky Soils Prepared Using Various Biochar Types, Anvesh Reddy

Masters Theses & Specialist Projects

Conserving the environment is an issue that is gaining popularity day by day. Phosphorus transfer from agricultural soils is an important environmental issue that is being closely observed as the transport of phosphorous to water bodies is adversely affecting water quality due to accelerated eutrophication. It is important to establish phosphorous models that accurately account for soil test phosphorous. Standard models like SWAT (Soil and Water Assessment Tool) and EPIC (Environmental Policy Integrated Climate) were designed for serving this purpose. They are now used as the basis for developing new models that can more accurately account for the phosphorus transport, …

On Metal Synthesis Of Some Substituted Rhenium And Manganese Complexes, Jaron Michael Thomas

Masters Theses & Specialist Projects

Heterocyclic organic and organometallic compounds (i.e. polypyrrole), and their derivatives, have been of great interest for conductive polymers due to their novel properties and environmental stability as compared to their non-aromatic analogs (i.e. polyacetylene). Our current interest focus upon the potential role of metal ligand bound pyridazines as the next generation of electronic devices that utilize the metal ligands bound to organics as the semiconducting material. Pyridazine is a 6-membered aromatic ring with two adjacent nitrogen atoms. These are promising candidates for a variety of materials and commercial applications; but they are difficult to get a metal ligand to fuse …

Designing Tools For Studying The Dynamic Glycome, John F. Rakus

Chemistry Faculty Research

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …

Judging A Book By Its Cover: Using Lectin Microarrays To Identify How Glycosylation Is Regulated, John F. Rakus

Chemistry Faculty Research

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …

Investigations Of Inter- And Intramolecular C-O Bond Forming Reactions Of Peroxide Electrophiles, Benjamin W. Puffer

Department of Chemistry: Dissertations, Theses, and Student Research

A common reaction to yield ethers relies on an alkoxide nucleophile and a carbon electrophile (Williamson ether formation). Ethers can also be formed by reactions with carbon nucleophiles and oxygen electrophiles by way of the peroxide functional group. We screened a number of carbon nucleophiles suitable for attack on dialkyl peroxides to form new C-O bonds. Also a novel approach using a peroxyketal electrophile is shown to increase the efficiency of this intermolecular reaction. This method of C-O bond formation can also be implemented intramolecularly, not seen before in the literature, to yield cyclic ethers. This approach requires the generation …

New Applications Of Mass Spectrometry For Drug And Lipid Analysis, Elizabeth Lauren Emerson

Graduate Theses and Dissertations

Mass spectrometry is an important tool used in many different disciplines and settings that include forensics, drug discovery, environmental analysis, and proteomics. Gas chromatography - mass spectrometry (GC-MS) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI - TOF MS) are two of the most important instruments used for analysis of compounds. Chapters 1 and 2 of this discussion use GC-MS for the investigation of synthetic cannabinoids in `K2' incense products and the detection of metabolites in urine samples from individuals suspected of consuming these mixtures. Analytical standards were synthesized and used for identification and confirmation of structures. Detection of …

Anti-Germinants As A New Strategy To Prevent Clostridium Difficile Infections, Amber Janece Howerton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridium difficileinfections (CDI) have emerged as a leading cause of hospital-associated complications. CDI is the major cause of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. The infective form of C. difficileis the spore, a dormant and hardy structure that forms under stress. Germination of C. difficile spores into toxin producing bacteria in the GI tract of susceptible patients is the first step in CDI establishment. Patient susceptibility occurs with a disruption of the natural gut microbiota by broad-spectrum antibiotics. Antibiotic treatments usually resolve CDI but refractory cases are on the rise. Of great concern is the …

The Use Of Rhenium(Vii) Oxide As A Catalyst For The Substitution Of Hemiacetals, Michael W. Richardson

Department of Chemistry: Dissertations, Theses, and Student Research

Rhenium (VII) oxides have proven to be mild and versatile catalysts in organic chemistry. They have previously been utilized to catalyze the transposition of allylic aclohols, Prins reaction, and reductive amination to name a few examples. This thesis reports the application of Re(VII) oxide in the substitution of hemi-acetals with a wide array of nucleophiles including oxo-, thio-, and peroxy-nucleophiles. These reactions proceed efficiently with rapid reaction times and high yields.

Adviser: Patrick H. Dussault

Preparation Of Nitrogen-Containing Heterocycles Via Cyclization Of Pyridine-Tethered Organolithiums, Elizabeth Archer

Master's Theses

No abstract provided.

Spectral Data For "Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations: Synthetic Studies Directed Toward The Frondosins", Do W. Lee, Rajesh K. Pandey, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins".

A short, 4-step route to the scaffold of frondosin A and B is reported. The [1-methoxycarbonyl-5-(2′,5′-dimethoxyphenyl)pentadienyl]Fe(CO)₃⁺ cation was prepared in two steps from (methyl 6-oxo-2,4-hexadienoate)Fe(CO)₃. Reaction of this cation with isopropenyl Grignard or cyclohexenyllithium reagents affords (2-alkenyl-5-aryl-1-methoxycarbonyl-3-pentene-1,5-diyl)Fe(CO)₃ along with other addition products. Oxidative decomplexation of these (pentenediyl)iron complexes, utilizing CuCl₂, affords 6-aryl-3-methoxycarbonyl-1,4-cycloheptadienes via the presumed intermediacy of a cis-divinylcyclopropane.

One-Pot Synthesis Of (Z)-B-Sulfonyl Enoates From Ethyl Propiolate, C. Wade Downey, Smaranda Craciun, Ana M. Neferu, Christina A. Vivelo, Carly J. Mueller, Brian C. Southall, Stephanie Corsi, Eric W. Etchill, Ryan J. Sault

Chemistry Faculty Publications

B-Sulfonyl enoates may be synthesized through a one-pot two-step sequence from ethyl propiolate with good to excellent selectivity for the Z isomer. Trialkylamines catalyze thioconjugate additions of aryl thiols, and alkoxides catalyze the addition of aliphatic thiols. Addition of meta-chloroperbenzoic acid (mCPBA) and LiClO₄ to the reaction mixture provides rapid access to the sulfonyl enoates. Yields of the pure Z isomer range from 51 – 90%.

One-Pot Three-Step Thioconjugate Addition-Oxidation-Diels–Alder Reactions Of Ethyl Propiolate, C. Wade Downey, Smaranda Craciun, Christina A. Vivelo, Ana M. Neferu, Carly J. Mueller, Stephanie Corsi

Chemistry Faculty Publications

Ethyl propiolate undergoes one-pot three-step thioconjugate addition-oxidation-Diels–Alder cycloaddition when treated with a variety of thiols in the presence of catalytic base, meta-chloroperbenzoic acid, lithium perchlorate, and cyclopentadiene. The reaction of S‑aryl thiols is catalyzed by trialkylamines, and the reaction of aliphatic thiols requires catalytic alkoxide base. Yields of the major diastereomer of the conveniently functionalized bicyclic products range from 47 to 81% depending upon the thiol reactant, which compares favorably to yields observed when the entire synthesis is performed step by step.

Synthesis And Characterization Of Chain-End Functionalization Of Glycosaminoglycans, Nikola Paulic, Jacob J. Weingart

Undergraduate Research Posters 2012

This presentation reports the CSU Summer Undergraduate Research project, which is the synthesis and characterization of chain-end functionalized CS derivatives, which will be used to investigate various bio-orthogonal conjugation reactions in attempt to create a novel CS-rTM conjugate.

Derivatization Of Free Glycans For Glycan Sensor And Glyco-Functionalization Applications, Rhonda D. Jones

Undergraduate Research Posters 2012

Glycans, especially, cell surface glycans acting as receptors, are involved in a wide range of biological processes. Analysis of the cell surface glycans provides a basis for understanding the molecular mechanism of glycan-mediated biological process. The present method can be applied in derivatizing sugars from natural sources for glycan sensor and glyco-functionalization applications.

Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells, also known as tumour-initiating cells (TICs), are identified as highly tumorigenic population within tumours and hypothesized to be main regulators in tumour growth, metastasis and relapse. Evidence also suggests that a tumour microenvironment plays a critical role in the development and progression of cancer, by constantly modulating cell–matrix interactions. Scientists have tried to characterize and identify the TIC population but the actual combination of extracellular components in deciphering the fate of TICs has not been explored. The basic unanswered question is the phenotypic stability of this TIC population in a tissue extracellular matrix setting. The in vivo …

Synthesis And Characterization Of Sugar Derivatives As Functional Gelators, Michael J. St Martin

LSU New Orleans Theses and Dissertations

Systems formed by the supramolecular assemblages of organic molecules known as organogelators and hydrogelators are currently, and only recently, a subject of great attention and promise. In this context, low molecular weight gelators (LMWGs) are of particular interest because they provide a bottom-up approach to the formation of supramolecular architectures through self-assembly. Gelator molecules do so via the initial formation of a one-dimensional array of individual molecules bound non-covalently through forces such as: hydrogen bonds, electrostatic forces, Van der Waals interactions, and other weak forces such as π-π interactions. These interactions then lead to secondary structure formation through a similar …