Physical Sciences and Mathematics Commons^™

Regioselective Catalytic Synthesis Of Potentially Bioactive 1,3,4-Selenadiazole, Mohamed Ali Mahmoud

Theses

Isoselenocyanates have a crucial role as reactants in chemical processes, facilitating the efficient synthesis of significant chemical intermediates and physiologically active chemicals. The utilization of (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides in a one-step procedure for the synthesis of the core structure of various heterocyclic compounds has been widely explored. This study focuses on the synthesis of 5-arylimino-1,3,4-selenadiazole derivatives through the reaction of isoselenocyanates with various substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides. The objective is to achieve selective and accurate formation of these derivatives. The derivatives exhibit a diverse range of functional groups on both aryl rings. The synthetic procedure is conducted under ambient conditions, promoting environmental …

Global Minimum Search For The Largest Ge Cage Stabilized By A Single Interstitial Metal Atom, Alexis Kiefer

Williams Honors College, Honors Research Projects

Recent joint experimental and theoretical studies showed that the largest Ge cage-like cluster features 14 Ge atoms that encapsulate a single transition metal atom in the [Nb@Ge₁₄]^3- cluster. The next larger experimentally confirmed Ge cluster exhibiting a cage-like geometry was found to be viable only when stabilized by two transition metal atoms in the [Co₂@Ge₁₆]^4- cluster. So, as of now, it is not clear whether a cage-like cluster made out of 15 Ge atom stabilized by a single transition metal is viable. Hence, the aim of this project is to find the …

The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck

Williams Honors College, Honors Research Projects

My proposed project will be creating large unilaminar vesicles with varying concentrations of DHA in the vesicles. The diffusion in and out of these vesicles will be tracked by using singular lipid molecules. These singular lipid molecules will be tagged with fluorescence and viewed using an internal reflection fluorescence microscope. The data collected over the course of this project will then be analyzed using Matlab. The result of the project will be to find the specific lipid diffusion constant of these unilaminar vesicles. The relationship between the concentration of DHA and lipid diffusion and membrane fluidity will be found as …

Enabling Technologies For Chemical Synthesis: I. Selective Microwave Heating; Ii. Synthesis And Regioselective Cyclotrimerizations Of Tethered 1,6-Diynes, Amir Tavakoli

Graduate Theses, Dissertations, and Problem Reports

Reaction discoveries, method developments, and technology advancements lie at the heart of synthetic organic chemistry. These innovations are essential for creating and manipulating complex molecules, which are the building blocks of many important chemical compounds, including pharmaceuticals, materials, and agrochemicals. Here, we first describe new methods to prepare neopentylene-tethered (NPT) 1,6-diynes which are valuable substrates for reaction discovery and target-oriented synthesis, especially in benzannulation strategies toward illudalane natural products. NPT 1,6-diynes have been employed as coupling partners in cyclotrimerization reactions for the synthesis of highly substituted benzene rings which present a persistent challenge in chemical synthesis and are underrepresented scaffolds …

Synthesis And Cyclotrimerization Of Sulfonyl Enynes, Alexa C. Martin

Graduate Theses, Dissertations, and Problem Reports

The synthesis of complex, polysubstituted aromatic rings from simple, non-aromatic building blocks is a consistent challenge to the synthetic community. Neopentylene ring fusions are found in several natural products but are largely absent from synthetic compound libraries. This discrepancy reflects the limitations in modern chemical synthesis. Utilizing, in part, a thoroughly developed fragmentation/olefination methodology from the Dudley Lab, a library of novel 1-sulfonyl-1,6-enynes have been developed. In this methodology, they are prepared in three steps from dimedone (5,5-dimethyl-1,3-cyclohexanedione), an inexpensive starting material. A total of 14 novel 1-sulfonyl-1,6-enynes were synthesized. These substrates were subjected to a novel benzannulation reaction based …

Sequential Block Copolymers Of Polyisobutylene And Polyolefins, Manwel Labib

Williams Honors College, Honors Research Projects

A two-step approach will be utilized to synthesize random polyolefin multiblock-copolymers. This strategy takes advantage of a,w-terminated telechelic polyolefins. Polypropylene (iPP)/polyethylene (PE) are picked because of their strength, and polyisobutylene (PIB) because of its hemocompatibility. This copolymer is theorized to make for robust bio-inert plastic, which can be used for surgical mesh implants.

1,2-Diamination Of Alkenes Via Reduction Of 1,2,3-Triazolinium Ions, Setareh Saryazdi

Theses and Dissertations--Chemistry

1,2-Diamine substructures are prevalent functional motifs in natural products, pharmaceutical compounds, and ligands. The interesting functionalities of 1,2-diamines have inspired many synthetic chemists to design various methodologies for preparing these structures from simple precursors such as alkenes. In this work, we described two different but related methods using simple and easily accessible reagents for 1,2-diamination of alkenes. In the first method, an alkene undergoes 1,3-dipolar cycloaddition with an organic azide to form a 1,2,3-triazoline. Subsequent N-alkylation of the generated 1,2,3-triazoline gives the 1,2,3-triazolinium ion, which is then hydrogenated over Raney Ni with a balloon of H₂ to produce …

1,2-Diazetidine As A New Amidomethylative Reagent To Control The Selectivity For The Synthesis Of N-Heterocycles And Ru(Ii)-Catalyzed Enantioselective Hydroarylation To Form Chromane Derivatives, Chaminda Lakmal Hetti Handi

Theses and Dissertations

1,2-Diazetidine is a four-membered ring heterocyclic compound which has two adjacent nitrogen atoms. However, the syntheses of C-unsubstituted 1,2-diazetidines are rarely reported in the literature. C-unsubstituted 1,2-diazetidines were synthesized through an operationally simple intermolecular vicinal disubstitution reaction between 1,2-dibromoethane and hydrazine with N-arylsulfonyl as the protecting group. Several different types of C-unsubstituted 1,2-diazetidines derivatives were synthesized with either two of the same or two different N-arylsulfonyl groups. The electronic and steric properties were analyzed using Raman spectroscopy and computational calculations. Then, several synthetic applications were demonstrated with 1,2-ditosyl-1,2-diazetidine (DTD). As a synthetic application, a nucleophilic ring-opening reaction of the diazetidine …

Synthesis And Characterization Of Re(I) Tricarbonyl Complexes Of 1,8-Naphthalimide, Priyanka Jagadeesa Prabhu

Electronic Thesis and Dissertation Repository

1,8-Naphthalimide fluorophores with amino-substituents absorb and emit in the visible region. The photophysical properties of this class of fluorophores can be modulated by altering the degree of Intramolecular Charge Transfer (ICT) in the excited state. Thus, several metal complexes with the 1,8-naphthalimide motif have been developed as cell imaging agents. In this project, four 1,8-naphthalimide ligands were synthesized by incorporating rigid linkers. Among these, three ligands also allowed the extension of π-conjugation to the naphthalimide moiety. In addition, a ligand was also synthesized without the use of a linker. Re(I) tricarbonyl complexes of these ligands were also synthesized and their …

A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali

Electronic Theses and Dissertations

Photodynamic therapy (PDT) has become a widely popular therapeutic approach for treating various types of cancer over the past several decades. PDT utilizes a photosensitizer, visible light, and oxygen, to produce reactive oxygen species (ROS) which can be used to treat cancer and inhibit growth of bacteria. In this study, a multifunctional solution that is comprised of Fe(III) ions, cationic meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (TMPyP), and 1,5-dihydroxynapthalene (1,5-DHN), was shown to produce reactive oxygen species (ROS) such as singlet oxygen (¹O₂) or hydroxyl radicals (ȮH) in aerobic or anaerobic environments, respectively, and in both environments, 1,5-DHN was oxidized …

The Rotational Spectrum Of 1,1-Diiodoethane, Michael Joseph Carrillo

Theses and Dissertations

The first chapter of this thesis introduces the basic theory of rotational spectroscopy. This includes the theory of a rigid rotor, centrifugal distortion, and hyperfine effects. The theory behind diatomic systems is explained first, and then expanded to the asymmetric top system. The second chapter encompasses a brief overview on the development of microwave spectroscopy and discusses the instruments that were utilized during this study, namely the cavity-based and chirped-pulse Fourier transform microwave spectrometers. Chapter three describes the quantum chemical calculation methods and basis sets that were applied throughout this study. Chapter four discusses the progress of data analysis of …

Synthesis And Characterization Of Novel Derivatives Of 1, 3, 4- 0xadiazole And Isoniazid, Ranem Mohammad Kaddoura

Chemistry Theses

This thesis describes the synthesis of novel derivatives of isoniazid and 1, 3, 4- oxadiazole piperazines and biological activities evaluation. The synthesis of the isoniazid derivatives (36a-Ɩ) was achieved by nucleophilic substitution of chloroacetylated isoniazid 34 with substituted piperazines (35a-Ɩ) produced isoniazidpiperazines (36a-Ɩ). On the other hand, cyclodehydration of chloroacetylated isoniazid 34 with POCl3 give the corresponding 1, 3, 4-oxadiazole 37 which upon treatment with substituted piperazines (35a-m) gave 1, 3, 4-oxadiazole-piperazines (38a-m). All newly synthesized compounds were purified and characterized using spectroscopic techniques including 1H-NMR, 13C-NMR, IR spectrometry and mass spectrometry.

The biological activity of the synthesized compounds has …

Exploration Of Cis-1,2-Diaminocyclohexane-Based Conformationally Locked Chiral Ligands In Asymmetric Synthesis, Carim Van Beek

University of the Pacific Theses and Dissertations

Natural products have been demonstrated to be of great significance to the pharmaceutical industry in the development of new drugs and medicine. Unfortunately, synthetic approaches to obtain these natural products often prove increasingly challenging due to the complexity of synthesizing the target drug in the proper stereochemistry. The availability of enantioselective reactions can play a pivotal role in overcoming this challenge, yielding access to optically pure intermediates and products. Chiral ligands based on a trans-1,2-diaminocyclohexane motif are often employed for this purpose and their complexes with transition metals have been demonstrated to act as efficient chiral catalysts in asymmetric reactions. …

Investigation Of The Intramolecular 1,3-Diaza-Claisen Rearrangement In The Ring Expansion Reactions Of Vinyl Pyrrolidines And Vinyl Piperidines, Teruki Watanabe

Graduate College Dissertations and Theses

The 1,3-diaza-Claisen rearrangement was discovered and developed in the Madalengoitia group since 2004. The rearrangement is initiated by the desulfurization of the electron deficient thiourea and isothiourea to obtain the highly electrophilic carbodiimide which can be reacted with an allylic tertiary amine to form the zwitterionic intermediate which then undergoes [3,3]-sigmatropic rearrangement. Previous investigation includes multiple examples of successful formation of complex guanidines through intermolecular and intramolecular variants. Providing an easy access to guanidine which is one of the most prevalent functional groups in the biologically relevant system, the rearrangement can be a valuable tool in the organic synthesis.

The …

Dna Recovery From Handwritten Documents Using A Novel Vacuum Technique, Patrick M. Mclaughlin

Student Theses

Investigations of many crimes such as robberies, kidnappings, and terrorism are often associated with the recovery of a paper document which has been written by the perpetrator. Paper can provide a variety of forensic evidence such as DNA, latent fingermarks, and indented writing. The focus of this study was the collection of probative DNA profiles from the text region of a handwritten note through a vacuum suction device without altering or destroying the document. Collection of DNA evidence was carried out in two separate groups. The first group involved 11 volunteers providing a handwritten note sample with unwashed hands. The …

Mechanistic Studies And Derivative Effects In 1, 3, 4- Oxadiazole Synthesis Via Cyclodehydration Reactions, Evan Huggins

Undergraduate Honors Thesis Projects

In the world of pharmaceutical synthesis, research to combat foreign pathogens is always necessary. Scientists have been exploring different methods in order to synthesize the most effective compounds in antibacterial, anticancer, anti-inflammatory, and many other treatments. A key component within these versatile compounds are 1,3,4-oxadiazoles. Current methods to synthesize these compounds are inefficient. This research seeks to improve oxadiazole synthesis; however, the mechanism of this reaction is unknown. The goal of this project was to study the mechanistic pathway in the discovered, one-pot cyclodehydration synthesis of 1,3,4-oxadiazoles. In the first part of this study, a diacylhydrazine intermediate was proposed. This …

Computational Study Of Lawesson’S Reagent Mediated Fluorenone Dimerization Forming 9,9’-Bifluorenylidene, Andrew Jourdan Eckelmann

MSU Graduate Theses

The ambition of this work is to start a path to the a priori rational design of high yield production for electron acceptors with finely tuned band gaps, from the comfort of an armchair. To this end, organic photovoltaics offer a cheap and sustainable means of manufacture using readily available materials and avoids the toxicity of some of the heavy metals used in first and second-generation solar cells such as cadmium. The microwave assisted Lawesson’s reagent mediated one-pot one-step solventless synthesis takes less than 3 minutes and results in an 84% yield of 9,9’-bifluorenylidene from two equivalents of fluorenone. While …

Synthesis Of Oxadiazoles And Examination Of Steric Effects In A Cyclodehydration Reaction, Norah Young

Undergraduate Honors Thesis Projects

The objective of this project is to develop a general substrate scope by testing various steric and electronic effects. This is pursued by developing triphenylphosphine dibromide (PPh3Br2) as an effective cyclodehydration reagent for use with a variety of hydrazides and sterically and electronically different benzoic acids. The two phases of the experiment include assessing yield through a cyclodehydration reaction and comparing that yield to the steric hindrance and molecular structure recorded in different databases. The cyclodehydration reaction uses ortho-substituted benzoic acid with store bought PPh3Br2, and compares those yields to the use of a two step-one pot reaction in place …

Formation Of Highly Functionalized Indole Through Carbon-Carbon Bond Cleavage, Ryan A. S. Pike

Chemistry and Chemical Biology ETDs

Indoles are one of the most abundant heterocycles found in nature and have a wide range of functions. There are a wide variety of indole synthesis methods known both in synthetic chemistry and through biosynthesis. Many of the known indole synthesis routes use a benzene derivative or cyclized ring structure derivative as a starting material. Here, we describe a novel synthetic method utilizing 1, 3-diketones and fumaronitrile with a catalytic amount of base to form a highly functionalized indole as our product. We have isolated and characterized 12 functionalized indoles.

Microtransplantation Of Rat Brain Neurolemma Into Xenopus Laevis Oocytes To Study The Effect Of Environmental Toxicants On Endogenous Voltage-Sensitive Ion Channels, Edwin Murenzi

Masters Theses

Microtransplantation of mammalian neurolemma into Xenopus laevis oocytes has been used to study ion channels in terms of their structure and function in the central nervous system. Use of microtransplanted neurolemma is advantageous in that tissue can be obtained from various sources, ion channels and receptors are present in their native configuration and they can be used to evaluate numerous channelpathies caused by environmental toxicants. Here we show that Xenopus oocytes injected with fragments of rat brain neurolemma successfully express functional native ion channels that are assembled in their own plasma membrane. Using a high throughput two electrode voltage clamp …

Approaches Toward Novel 1,2,3-Triazole Sensors For The Detection Of Anions And Heavy Metal Cations, Richard D. Govan

Electronic Theses and Dissertations

Cations and anions play pivotal roles in biological and physiological processes, however an imbalance in concentration of any ion can be detrimental. Therefore, research into the selective recognition of anions and heavy metal cations has acquired much attention. One approach involves the use of chemosensors. Upon interaction with targeted analytes, chemosensors produce a distinct response, in some cases a fluorescent or colorimetric signal. The 1,2,3-triazole unit has much potential as a chemical sensor due to its unique photophysical properties. The specificity, selectivity, and signaling mechanism of triazole sensors can be tuned with conjugation in the motif and choice and placement …

New Approaches To Heterocycle Synthesis: A Greener Route To Structurally Complex Protonated Azomethine Imines, And Their Use In 1,3-Dipolar Cycloadditions, Ram Chandra Dhakal

Graduate College Dissertations and Theses

1-Aza-2-azoniaallene salts are reactive intermediates that undergo [3+2] cycloaddition with many different types of multiple bonds. For the past several years, the Brewer group has studied the reactivity of these intermediates in intramolecular reactions, and have discovered that these cationic heteroallenes can react through a variety of other, mechanistically distinct, pathways to give different classes of nitrogen heterocycles. For example, prior work in the Brewer group revealed that 1-aza-2-azoniaallene salts could react in an intramolecular [4+2] cycloaddition reaction to give protonated azomethine imine salts containing a 1,2,3,4-tetrahydrocinnoline scaffold. Further study of the scope and limitations of this Diels-Alder-like reaction are …

Electrogenerated Chemiluminescence Of Luminophores And Enhancement With Melatonin, Sarah Michelle Roughton

MSU Graduate Theses

The photoluminescent (PL), electrochemical, and electrogenerated chemiluminescent (ECL) properties of 1,5-I-Aedans (N-(iodoacetylaminotheyl)-1-naphthylamine-5-sulfonic acid) in aqueous buffered (KH2PO4) and 50:50 (v/v) acetonitrile:KH2PO4 solutions were obtained. Tri-n-propylamine (TPrA) was used as the oxidative-reductive coreactant. The PL efficiencies (em) were 1.83 in KH2PO4 and 4.81 in mixed solvent compared to Ru(bpy)32+ standard solutions (em = 1.0). 1,5-I-Aedans displayed quasi-reversible oxidative electrochemistry in aqueous solutions and irreversible to quasi-reversible oxidation in mixed solvent. ECL efficiencies (ecl) were obtained by comparison to a Ru(bpy)32+/TPrA (bpy = 2,2'-bipyridine) standard (ecl = 1) and were higher in KH2PO4 (ecl = 6.8 x 10-4) than in the mixed …

Synthesis, Structure-Activity Relationship Study, And Mode Of Action Study Of 1,4-Naphthoquinone Based Anticancer And Antimicrobial Agents, Jaya P. Shrestha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The first three projects involve the synthesis and the mode of action study of 1,4-naphthoquinone based anticancer agents. These anticancer agents are highly potent against a wide range of cancer cell lines. These compounds showed ~8-fold selectivity towards the lung cancer cell line than the normal cell line. We also studied the mode of action and observed that generation of reactive oxygen species is the primary mode of action.

The final project involves the synthesis of multi-cationic antimicrobial agents. These compounds are active against both bacteria and fungi. These compounds are very easy to synthesize and can be scaled up …

Synthetic Methods For The Preparation Of 1,3-S,O-Esters, Α-Phosphonovinyl Triflates, And Α-Alkynylphosphonates, David P. Kercher

Master of Science in Chemical Sciences Theses

A broad and systematic study was conducted on synthetic methods to efficiently synthesize 1,3-S,O-esters, α-phosphonovinyl triflates, and α-alkynylphosphonates under mild reaction conditions. The master’s thesis is composed of two projects; the first project is titled “Synthesis of 1,3-S,O-Esters” and the second project is titled “Synthesis of α-Phosphonovinyl Triflates and α-Alkynylphosphonates.” The first project outlines a synthetic route to conveniently prepare novel α-functionalized 1,3-S,O-esters via an acid-promoted hydrolysis of α-functionalized α-oxoketene dimethylthioacetals. The second project, unrelated to the first project, primarily focuses on extensive synthetic methodology developed to prepare …

Chiral Boro-Phosphates In Asymmetric Catalysis: 1,4-Reduction Of Enones And Reductive Aldol, Susana Sorina Lopez

USF Tampa Graduate Theses and Dissertations

The biological activity of the pharmaceutical drugs often depends on how it fits with a receptor making stereochemistry a key component. Selective reactions can limit or avoid the mixture of enantiomers obtained. One such reaction is the selective reduction of a carbon-carbon double bond in the presence of a carbonyl. Although efficient, current asymmetric synthesis methods have limitations such as harsh reaction conditions, the high costs of chiral catalysts and the toxicity of the metal-based catalysts. Catalysts derived from small organic molecules have become an attractive alternative which have been explored more rigorously in recent years. Using a BINOL-derived boro-phosphate …

Synthesis, Characterization And Evaluation Of Lectin-Binding Properties Of 1,2-Cis-Glycosides, Bo Meng

Doctoral Dissertations

This dissertation presents a state-of-the-art research of 1,2-cis-glycosides, including synthetic methodology development, combinatorial total synthesis of galactoside ligands, construction of glycomicroarray surfaces, and quantitative evaluation of carbohydrate–lectin binding properties.

In Chapter 1, as a general introduction, various strategies that have been developed for the stereoselective construction of 1,2-cis-O-glycosidic bond are reviewed. 1,2-cis-O-Glycoside structural units are ubiquitous in nature, and they are extensively involved in numerous biological activities. The systematic identification and evaluation of the roles of carbohydrates usually relies on practical synthetic approaches to afford pure carbohydrates in considerable quantities. …

Strategies For Photochemical And Thermal Modification Of Materials, Sara Ghiassian

Electronic Thesis and Dissertation Repository

The modification of materials/surfaces is central to numerous applications ranging from opto-electronic devices to biomedical implants and drug delivery. Thus, there exists a high motivation for improving the methodologies which can be employed in order to modify surfaces in a selective and efficient fashion. One of the major goals of surface engineering is to control the chemical composition at the material interface. The fine control of the surface properties is a field of intense research as the performance of functional materials is strongly related to the processes and interactions that are occurring at the materials’ interface.

In general, the modification …

Synthesis And Characterization Of Five New Tetrakis(N-Phenylacetamidato) Dirhodium(Ii) Amine Complexes And One Molybdenum Cofactor Described Crystallographically, Cragin K. Harris

Electronic Theses and Dissertations

Six new crystal structures were determined using a Rigaku Mercurcy 375/MCCD(XtaLab mini) diffractometer. The structure of a molybdenum cofactor was solved resulting in an R1 (R1 = Σ ||Fo| - |Fc|| / Σ |Fo|) of 3.61% despite the presence of a disordered DMSO molecule. New Tetrakis(N-phenylacetamidato) Dirhodium(II) complexes were synthesized and characterized. Two 2,2-cis-[Rh2(NPhCOCH3)4]•(C3H4N2)x where x= 1 or 2 were successfully crystallized and solved with R1 values below 5%. Additional studies were conducted via NMR to observe formation of both products. Three potential catalysts were synthesized starting with 3,1-[Rh₂(NPhCOCH₃)₄]. The resulting compounds were a …

Investigation Of The Crystallization Of Dnl-6 And Ft-Raman Spectroscopic Investigation Of Guest Molecules In Mofs, Maxwell Goldman

Electronic Thesis and Dissertation Repository

Microporous solids are a widely used material in adsorption, storage and catalysis. In this thesis, the crystallization of the silcoaluminaphosphate DNL-6 was characterized using powder X-ray diffraction and solid state nuclear magnetic resonance. Two crystallization routes of the SAPO DNL-6 were studied, which are the hydrothermal method and the dry-gel conversion method. Both methods followed the same crystallization pathway and showed a layered intermediate that is then transformed into DNL-6. The reaction requires two templating agents to create the RHO topology and silicon substitutes into the framework by replacing single phosphorous atoms.

This thesis contains the conformational analysis of halocarbons …