Organic Chemistry Commons^™

A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li

Open Access Theses

Proton affinity (PA) is a fundamental property that is related to the structure and reactivity of a molecule. Currently, very few experimental PA values are available for organic radicals and none for biradicals. Equilibrium methods cannot be used for these measurements. The traditional bracketing method is based on monitoring reactions of different reference bases with known proton affinities with the protonated analyte for the occurrence of exothermic proton transfer to determine the upper and lower limits of proton affinity. However, the energy deposited into the precursor ions upon CAD when forming protonated radicals may cause endothermic proton transfer reactions occur …

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard

Open Access Dissertations

The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been shown to act as the primary driver for these chemical depletions, although both chlorine and iodine atoms also contribute. Molecular bromine, along with its oxidation products, have been well studied in the Arctic, yet chlorine has not. Chlorine is known to impact the local oxidation capacity via its high reactivity with volatile organic compounds. Despite …

Comprehensive Organic Synthesis Ii (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Jeffrey Glans' review focuses on the online version available through ScienceDirect.

Knochel, Paul and Gary A. Molander, eds. Comprehensive Organic Synthesis II. 2nd ed. Amsterdam; Waltham, MA: Elsevier, 2014. Web.

http://www.sciencedirect.com/science/referenceworks/9780080977430

ISBN: 9780080977430 (e-book)

New Methods For Synthesis Of Organic Peroxides And Application Of Peroxide Electrophiles To Synthesis Of Functionalized Ethers, Shiva Kumar Kyasa

Department of Chemistry: Dissertations, Theses, and Student Research

New Method for Synthesis of Alkyl Hydroperoxides: There are a number of methods reported for synthesis of alkyl hydroperoxides, but most of them suffer either from poor yields or the formation of unwanted side products. I will be discussing new methodology for efficient synthesis of pure samples of 1° and 2° alkyl hydroperoxides via alkylation of readily available cyclododecanone 1,1-dihydroperoxide followed by hydrolysis of the resulting bis peroxyacetals.

Peroxide Electrophiles for Synthesis of Functionalized Ethers: Peroxides are underexplored functional groups as precursors for C-O bond formation and ether synthesis. The reactivity of dialkyl peroxides towards organometallics such as alkyl lithium …

Toward Electronic Materials Based On Metal Pincer-Type Complexes, Jeewantha Sampath Hewage

Master's Theses (2009 -)

There is currently a lot of interest in developing electrically conducting or semiconducting metal-organic frameworks (MOF's), highly porous materials constructed by organic ligands bridging metal centers. Typically MOF's are non-conducting and, moreover, they are susceptible to hydrolytic degradation. If hydrolytically stable and electrically conducting MOFs could be realized, then revolutionary new technologies could be envisioned. Currently, organic dicarboxylates are used as bridging organic ligands and one simple strategy to obtain the desired materials is to explore other ligand systems. Pincer ligands are organic compounds that are uninegative and bind metals in a tridentate, meridional fashion with two five-member chelate rings. …

Violacein Induces P44/42 Mitogen-Activated Protein Kinase‑Mediated Solid Tumor Cell Death And Inhibits Tumor Cell Migration, Toral Mehta, Koen P. Vercruysse, Terrance Johnson, Anthony Okechukwu Ejiofor, Elbert Myles, Quincy A. Quick

Chemistry Faculty Research

Microbial secondary metabolites have emerged as alternative novel drugs for the treatment of human cancers. Violacein, a purple pigment produced by Chromobacterium violaceum, was investigated in the present study for its anti‑tumor properties in tumor cell lines. Clinically applicable concentrations of violacein were demonstrated to inhibit the proliferative capacity of tumor cell lines according to a crystal violet proliferation assay. The underlying mechanism was the promotion of apoptotic cell death, as indicated by poly(ADP ribose) polymerase cleavage and p44/42 mitogen‑activated protein kinase signaling determined by western blot analysis. Collectively, this provided mechanistic evidence that violacein elicits extracellular-signal regulated kinase‑induced apoptosis …

The Detection And Quantitative Analysis Of Endocannabinoids And Endogenous Fatty Acid Amides In Apis Mellifera And Tribolium Castaneum, Perry Robert Mitchell Jr.

USF Tampa Graduate Theses and Dissertations

Endocannabinoids, and the fatty acid amides from which they are a member, have garnered greater scientific interest in the last two decades due to the cannabimimetic properties of these endogenous molecules. The most well-known of these is Anandamide, which has thus far been discovered in several species of animal ranging from C. elegans, fruit flies, to bovine and humans. Because of the importance and increasing impact of these compounds a brief overview is first presented herein, with a major focus on the N-acyldopamines due to the direct impact they potentially pose to human physiology.

Secondly, the detection and …

Gamma-Aapeptides As A New Class Of Peptidomimetics: Synthesis, Structures, And Functions, Haifan Wu

USF Tampa Graduate Theses and Dissertations

Peptidomimetics are synthetic oligomers that resemble the activities of peptides. Their advantages over peptides include high stability towards proteolysis and enormous chemical diversity. Over the past two decades, there have been extensive efforts to develop peptide mimics, such as beta-peptides, peptoids, D-peptides, etc. The research on peptidomimetics have led to many important applications in both medicinal and material science. In order to explore new functions, the discovery of peptidomimetics with novel frameworks is essential. We reported the synthesis and evaluation of a new class of peptidomimetics, termed as gamma-AApeptides. Previous studies of gamma-AApeptides have revealed that gamma-AApeptides are highly resistant …

Design And Synthesis Of Bioactive Peptidomimetics, Yaogang Hu

USF Tampa Graduate Theses and Dissertations

Protein-Protein Interactions (PPIs) play a very important role in biological functions and therefore the inhibition of specific Protein-Protein Interactions has a huge therapeutic value. The most successful small molecular PPIs inhibitors do not fit with the prevalent `Rule of Five' drug profile. To overcome the disadvantages of small molecular PPIs inhibitors, peptide based PPIs inhibitors were developed. Herein we describe the development of a new class of peptidomimetics AA-peptides. The AApeptides were designed based on chiral PNA backbone. Substitution of nucleobases yields AApeptides that are resistant to proteolysis and capable of mimicking peptides. Two types of AApeptides were discussed in …

Towards The Total Synthesis Of (+/-)-Gephyrotoxin 287c, Maciej E. Domaradzki

Dissertations, Theses, and Capstone Projects

Studies directed toward the total synthesis of (+/-)-Gephyrotoxin 287C are described herein. Even though the target alkaloid has been synthesized four times to date, it still presents an interesting synthetic challenge. Our ultimate goal is to develop an efficient enantioselective synthetic route utilizing oxazolone chemistry in order to demonstrate its utility as a dienophilic component in intramolecular Diels-Alder reactions. This is part of a greater ongoing study aimed at a range of suitable alkaloid targets.

Chapter 1 provides introduction to frog toxins as secondary metabolites and subsequently shifts to the target alkaloid. (+/-)-Gephyrotoxin 287C was originally described by Daly and …

Synthesis Of Dinucleoside Acylphosphonites By Phosphonodiamidite Chemistry And Investigation Of Phosphorus Epimerization, William H. Hersh

Publications and Research

The reaction of the diamidite, (iPr2N)2PH, with acyl chlorides proceeds with the loss of HCl to give the corresponding acyl diamidites, RC(O)P(N(iPr)2)2 (R = Me (7), Ph (9)), without the intervention of sodium to give a phosphorus anion. The structure of 9 was confirmed by single-crystal X-ray diffraction. The coupling of the diamidites 7 and 9 with 5′-O-DMTr-thymidine was carried out with N-methylimidazolium triflate as the activator to give the monoamidites 3′-O-(P(N(iPr)2)C(O)R)-5′-O-DMTr-thymidine, and further coupling with 3′-O-(tert-butyldimethylsilyl)thymidine was carried out with activation by pyridinium trifluoroacetate/Nmethylimidazole. The new dinucleoside acylphosphonites could be further oxidized, hydrolyzed to the H-phosphonates, and sulfurized to …

Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati Nigudkar, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

Recent developments in stereoselective 1,2-cis glycosylation that have emerged during the past decade are surveyed herein. For detailed coverage of the previous achievements in the field the reader is referred to our earlier reviews: A. V. Demchenko, Curr. Org. Chem., 2003, 7, 35–79 and Synlett, 2003, 1225–1240.

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …

Scale Up Isolation Of Aaptamine For In Vivo Evaluation Indicates Its Neurobiological Activity Is Linked To The Delta Opioid Receptor, Nicole L. Mcintosh, Eptisam Lambu, Laura Millan-Lobo, Fei Li, Li He, Phillip Crews, Jennifer L. Whistler, Tyler Johnson

Student Research Posters

Opioid receptors belong to the large superfamily of seven transmembrane-spanning (7TM) G protein-coupled receptors (GPCRs). As a class, GPCRs are of fundamental physiological importance mediating the actions of the majority of known neurotransmitters and hormones. The Mu, Delta, and Kappa (MOP, DOP, KOP) opioid receptors are particularly intriguing members of this receptor family as they are the targets involved in many neurobiological diseases such as addiction, pain, stress, anxiety, and depression. Recently we discovered that the aaptamine class of marine sponge derived natural products exhibit selective agonist activity in vitro for the DOP versus MOP receptor. Our findings may explain …

Efficient Utilization Of Solar Energy In Dye-Sensitized Solar Cells And In The Photocatalytic Reduction Of Carbon Dioxide, Aron Joel Huckaba

Electronic Theses and Dissertations

One of the most important questions humanity will face in the next 100 years is going to be "What will happen when oil runs out?" This dissertation describes efforts to utilize solar energy to improve renewable energy technology in two ways: First, through the improvement of dye sensitized solar cells by theimprovement of D-π-A dye subunits, the development of practical sensitizers, and progress towards stable, tunable redox shuttles. A novel indolizine donor subunit was synthesized that was shown to be the strongest reported donor. Dyes made from this novel donor and devices using the Γ-/I 3- reached up to 5.4% …

Methods Of Analysis For Fermentation Science Products Using Various Analytical Techniques, Casey Jay Howdieshell

Online Theses and Dissertations

Fermentation science, the study of microorganisms as they digest food sources to produce usable products for consumption, has been around since the dawn of modern civilization. Historically, the fermentation process has been utilized for the production of alcoholic beverages. More recently, however, the production of bioethanol and biodiesel as a fuel source alternative to classical fossil fuels has gained increased popularity. As with any synthetic process, derivations and optimizations for ideal production are needed. As such, analytical techniques must be implemented to ensure quality control and pinnacle efficiency. This body of work describes analytical techniques providing key qualitative and quantitative …

Low-Level Mercury Causes Inappropriate Activation In T And B Lymphocytes In The Absence Of Antigen Stimulation, K. L. Weigand, J. L. Reno, B. M. Rowley

Journal of the Arkansas Academy of Science

The immune system primarily utilizes two cell types for adaptive immunity: T lymphocytes and B lymphocytes. T lymphocytes are activated when antigen presenting cells (APCs) present antigen to membrane-bound T cell receptors. B lymphocytes are activated when an antigen binds to receptors embedded in the plasma membrane. In both T and B cells this antigen binding crosslinks the receptor complexes and initiates the signal transduction cascade. These cascades frequently consist of a series of intracellular molecules becoming phosphorylated in a step-wise fashion. Once activated, these cells differentiate into effector cells that clear out the stimulating antigen. Mercury, which is a …

Palladium-Catalyzed Annulation Of 9-Halophenanthrenes With Alkynes: Synthesis, Structural Analysis, And Properties Of Acephenanthrylene-Based Derivatives, En Chih Liu, Min-Kuan Chen, Jen-Yi Li, Yao-Ting Wu

Chemistry Faculty Research & Creative Works

The palladium-catalyzed annulation of 9-bromoand 9-chlorophenanthrenes with alkynes gave 4,5-disubstituted acephenanthrylenes in yields of 58–95% (9 examples). Asymmetric alkynes, such as 1-phenyl-1-propyne, 1-phenyl- 1-hexyne, and 1-cyclopropyl-2-phenylethyne, regioselectively form (cyclo)alkyl-substituted products, following the regular rule that governs the carbopalladation of alkynes. This synthetic protocol can also be utilized in annulations with several p-extended bromoarenes, such as 7-5] helicene, 5- 4] helicene, 9-bromoanthracene, 3-bromoperylene, and 3-bromofluoranthene, to give the corresponding annulated products in moderate to good yields (51–86 %; 6 examples). Similarly, bromocorannulene produced highly curved 1,2-disubstituted cyclopentacorannulenes. Reactions of 6,12-dibromochrysene and 4,7-4] helicene with di(4-tolyl) ethyne provided the twofold annulated products …

Palladium-Catalyzed Reaction Of Haloarenes With Diarylethynes: Synthesis, Structural Analysis, And Properties Of Methylene-Bridged Arenes, Che-Wei Lee, En Chih Liu, Yao-Ting Wu

Chemistry Faculty Research & Creative Works

Fluorenes and methylene-bridged polyarenes were easily and efficiently synthesized from haloarenes (or aryl triflates) and diarylethynes by a one-pot, two-step procedure. This protocol involves the palladium-catalyzed cycloisomerization and a subsequent base-mediated retro-aldol condensation. A major advantage is that the starting materials need not have ortho functional groups to complete the annulation. The backbone of the designed products was enlarged using dihaloarenes, highly π-conjugated haloarenes, or diarylalkynes. The mechanism of the formation of benzo[a]fluorene was investigated. The bowl-shaped structure of methylene-bridged indenocorannulene was verified by X-ray crystallography. The photophysical and electrochemical properties of the products thus prepared were investigated.

Generation Of 2-Adamantylidenecarbene From A Phenanthrene-Based Precursor, Christine E. Wamsley

Honors Theses

This thesis examines the generation of 2-adamantylidenecarbene from a phenanthrene-based precursor. A three-step synthetic procedure was used to generate the 2-adamantylidenecarbene precursor, which subsequently underwent photolysis to produce 2-adamantylidenecarbene. This product was trapped with cyclohexene. No evidence of a ring expansion to 4-homoadamantyne was observed. It was also noted that the target precursor underwent rearrangement during photolysis, leading to the formation of an isomer containing a seven-membered ring. This isomer did not photolyze. Additionally, computational studies were performed using Gaussian 09. Geometries were initially optimized and then, the single point energies of the singlet and triplet carbene states were calculated. …

A Simpler Route To Building Photochromic Cinnamaldehyde Semicarbazones, Byron R. Ebbert

Masters Theses

Photochromic semicarbazones are an interesting group of compounds that show potential in a broad range of applications, including as a more environmentally friendly replacement for photochromic metal complex compounds. Previous work has shown the feasibility to synthesize photochromic cinnamaldehyde semicarbazones (CSCs) from a benzaldehyde and a protected acetaldehyde Wittig reagent. A new, quicker, and cheaper approach to constructing these CSCs from crotonaldehyde was explored in this research. A three reaction sequence would convert crotonaldehyde to a CSC; first, an allylic bromination of the semicarbazone with N-bromosuccinimide (NBS); second, an Arbuzov reaction to prepare the semicarbazone phosphonate; and finally a condensation …

A Convergent Approach To The Continuous Synthesis Of Telmisartan Via A Suzuki Reaction Between Two Functionalized Benzimidazoles, Alex D. Martin

Theses and Dissertations

A direct and highly efficient synthesis has been developed for telmisartan, the active ingredient in the widely prescribed antihypertensive drug Micardis®. This approach brings together two functionalized benzimidazoles using a high-yielding Suzuki reaction that can be catalyzed by a homogeneous palladium source or palladium on a solid support.

The ability to perform the cross-coupling reaction was facilitated by the regio-controlled preparation of a 2-bromo-1-methylbenzimidazole precursor. The method developed is the first reported selective bromination at the 2-position of a benzimidazole and produces the first major precursor in high yield (93%). The second precursor, potassium (4-methyl-2-propylbenzimidazol-6-yl) trifluoroborate, was prepared from commercially …

Mitochondria- Targeted Antioxidant Skq1 Reverses Glaucomatous Lesions In Rabbits, Elena N. Iomdina, Inna P. Khoroshilova-Maslova, Olga V. Robustova, Olga A. Averina, Nadezhda A. Kovaleva, Gjumrakch Aliev, V. Prakash Reddy, Andrey A. Zamyatnin, Maxim V. Skulachev, Ivan I. Senin, Vladimir P. Skulachev

Chemistry Faculty Research & Creative Works

Glaucoma is the main cause of irreversible blindness worldwide. This disease is characterized by apoptosis of retinal ganglion cells (RGC) and visual field loss that seems to be related to elevated intraocular pressure (IOP). Several lines of evidences have implicated the crucial role of mitochondrial dysfunction in the pathogenesis of glaucoma. Increased mitochondrial oxidative stress in RGC may underlie or contribute to susceptibility of RGC to apoptosis. In our work we (i) designed a rabbit model of chronic, moderately elevated IOP for studying glaucoma and (ii) demonstrated efficacy of mitochondria- Targeted antioxidant SkQ1 as a tool to reverse several traits …

Structure-Activity Relationships For The Water-Gas Shift Reaction Over Supported Metal Catalysts, Kaiwalya D. Sabnis

Open Access Dissertations

The Water-Gas Shift (WGS) reaction (CO + H₂O → CO₂ + H₂) is an important chemical process for industrial hydrogen production. The overall goal of this project is to use kinetic experiments and in situ characterization techniques in tandem, in order to derive structure-activity relationships for various catalytic systems. These relationships facilitate the rational catalyst design by identification of catalyst descriptors. In order to establish such relationships, various studies were undertaken, such as (i) effect of transition admetals on the WGS catalysis by molybdenum carbide (ii) effect of residual oxygen content on the performance of …

Design And Synthesis Of Isatin-Based Caspase Inhibitors For Ruthenium Caging Applications, Kasun Chinthaka Ratnayake

Wayne State University Theses

ABSTRACT

DESIGN AND SYNTHESIS OF ISATIN BASED CASPASE INHIBITORS FOR RUTHENIUM CAGING APPLICATIONS

by

KASUN CHINTHAKA RATNAYAKE

August 2015

Advisor: Jeremy J. Kodanko, Ph.D.

Major: Chemistry (Organic)

Degree: Master of Science

Apoptosis is the energy dependent programmed cell death. Improper function of apoptosis could lead to diseases such as cancers, strokes, Alziemer’s disease. Caspases are the enzymes involved in the later stage of this process. Peptidyl and non-peptidyl caspase inhibitors have been synthesized recently. These non-peptidyl compound classes which consist of pyrrolidinyl-5-sulfo isatins have showed a greater potency against executioner caspases, caspase-3 and -7. According to literature and for further …

Preparation, Chemistry, And Characterization Of Hypervalent Organosulfur Fluorides, Paul R. Savoie

Legacy Theses & Dissertations (2009 - 2024)

Since the discovery of the pentafluorosulfanyl (SF5) group around the 1960s, progress in exploring the chemistry of aliphatic SF5-containing compounds stagnated because of a lack of efficient synthetic methods. More recent developments in the preparations of SF5-containing compounds afforded easier access to these compounds, and sparked great interest in exploring their chemistry. Chapter 1 discusses the development of efficient methods used to prepare SF5-containing aliphatic compounds.

Experimental And Computational Investigation Of Selected Β-Hydroxy Carbenes, Joseph D. Deangelo

Honors Theses

The photolytic precursor to the sterically hindered β-bis(tert)-butanol carbene, 3-(1a,9b-dihydro-1H-cyclopropa[l]phenanthren-1-yl)-2,2,4,4-tetramethylpentan-3-ol was prepared in three steps from phenanthrene. Photolysis of the precursor generates the desired β-hydroxy carbene, an intermediate, which subsequently rearranges into two different observed products from an intramolecular C-H insertion and alkyl shift. Four intramolecular mechanisms were ultimately considered to account for the possible rearrangement pathways. Computational studies using density functional theory are also presented.

In addition, the photolytic precursors to two cyclic β-hydroxy carbenes, 1-(1a,9b-dihydro-1H-cyclopropa[l]phenanthren-1-yl)cyclopropan-1-ol and 1-(1a,9b-dihydro-1H-cyclopropa[l]phenanthren-1-yl)cyclobutan-1-ol, were also prepared through different synthetic routes from phenanthrene. …

Triphenylamine-, Porphyrin- And Fullerene-Based Derivatives For Photovoltaic And Other Applications, Danisha Marie Rivera Nazario

Open Access Theses & Dissertations

Proper collection of charges at the electrodes is an important process in organic solar cells. Interfacial layers between the electrodes and the photoactive layer have been design to improve charge collection and ohmic contacts. The most studied interfacial layer between the anode and the photoactive layer is the negatively charged polymer poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), that possesses good hole transporting ability. However, inhomogeneities at the surface of the electrode after deposition of the polymer lower the stability and performance of the OPV devices. Triphenylamine (TPA) derivatives have received increased attention in the organic solar cells (OSCs) field because of their favorable light …

Inhalable Nanocomposites And Anticancer Agents For Cancer Therapy, Nathanael A. Stocke

Theses and Dissertations--Chemical and Materials Engineering

Cancer is designated as the leading cause of mortality worldwide and lung cancer is responsible for nearly 30% of all cancer related deaths. Over the last few decades mortality rates have only marginally increased and rates of recurrence remain high. These factors, among others, suggest the need for more innovative treatment modalities in lung cancer therapy. Targeted pulmonary delivery is well established for treating pulmonary diseases such as asthma and provides a promising platform for lung cancer therapy. Increasing local deposition of anticancer agents (ACAs) and reducing systemic exposure of these toxic moieties could lead to better therapeutic outcomes and …

Design, Synthesis, And Pharmacological Evaluation Of Three Series Of Lobelane Analogs As Inhibitors Of The Vesicular Monoamine Transporter (Vmat2), John P. Culver

Theses and Dissertations--Pharmacy

Methamphetamine (METH) abuse is a serious problem in the United States and worldwide. The reward experienced by METH users is due to the increase in extracellular dopamine (DA) concentrations caused by an interaction between METH and the DA transporter (DAT) as well as the Vesicular Monoamine Transporter-2 (VMAT2). The reward felt by users of METH leads to further use of the drug and subsequent abuse. The current project examined the ability of three novel series of lobelane analogs to interact with a binding site on the Vesicular Monoamine Transporter-2 (VMAT2) in an attempt to inhibit the effects of METH. Lobelane …