Synthesis And Catalytic Evaluation Of Novel C-Alpha-Methyl-Beta-Proline Analogues, And Concise Synthetic Approach To Nh-Fmoc-S-Trityl-C-Alpha-Methyl Cysteine, 2017 University of Southern Mississippi
Synthesis And Catalytic Evaluation Of Novel C-Alpha-Methyl-Beta-Proline Analogues, And Concise Synthetic Approach To Nh-Fmoc-S-Trityl-C-Alpha-Methyl Cysteine, Hari Kiran Kotapati
In the field of chemistry there is a growing demand for small molecule organocatalysts such as amino acids, more specifically proline and its analogues, which could catalyze various key chemical reactions in the synthesis of several biologically important molecules. Even though natural proline is reported to catalyze various chemical reactions, its use as organocatalyst is limited mainly due to the solubility issues in the reaction media and high catalyst loadings, which is not very ideal for bulk scale manufacturing. To address these limitations we planned to develop unnatural analogues of proline that could catalyze the reactions with lower catalyst loadings ...
The Modified Stereospecific Stille Reaction: Palladium-Catalyzed Cross-Coupling Reactions Involving Secondary And Tertiary Alkyl Carbastannatranes, 2017 The Graduate Center, City University of New York
The Modified Stereospecific Stille Reaction: Palladium-Catalyzed Cross-Coupling Reactions Involving Secondary And Tertiary Alkyl Carbastannatranes, Chao-Yuan Wang
All Graduate Works by Year: Dissertations, Theses, and Capstone Projects
Organic chemistry is present in all domains of everyday life, from polymer production to medicine. In order to synthesize complex compounds, it is often necessary to make new carbon-carbon bonds. Transition metal catalysts, particularly those derived from second and third row metals such as Pt, Pd, Rh, and Ir metals, display remarkable efficiency for the formation of carbon-carbon and carbon-heteroatom bonds. In the first chapter, introduction of transition metal-catalyzed cross-coupling reactions is given. While the formation of C(sp2)–C(sp2) bonds has been studied extensively, C(sp3)-C(sp2) bond formation still presents a challenge ...
Electronic And Magnetic Properties Of Carbon-Based And Boron-Based Nano Materials, 2017 Clark Atlanta University
Electronic And Magnetic Properties Of Carbon-Based And Boron-Based Nano Materials, Rosi Gunasinghe
Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University
The structural and electronic properties of covalently and non-covalently functionalized graphene are investigated by means of first-principles density-functional-theory. The electronic characteristics of non-covalently functionalized graphene by a planar covalent organic framework (COF) are investigated. The aromatic central molecule of the COF acts as an electron donor while the linker of the COF acts as an electron acceptor. The concerted interaction of donor acceptor promotes the formation of planar COF networks on graphene. The distinctive electronic properties of covalently functionalized fluorinated epitaxial graphene are attributed to the polar covalent C–F bond. The partial ionic character of the C–F bond ...
Studies Directed Towards The Iridium Catalyzed Synthesis Of New Carbon-Nitrogen Bonds., 2017 University of New Orleans
Studies Directed Towards The Iridium Catalyzed Synthesis Of New Carbon-Nitrogen Bonds., Maria Lindsay
University of New Orleans Theses and Dissertations
Amines are ubiquitous in nature and serve a variety of functions in living organisms. Because of this fact amines are of great biological and pharmaceutical interest. The iridium catalyst (pentamethylcyclopentadienyl) iridium dichloride dimer ([Cp*IrCl2]2) has been used in a number of ways to synthesize new carbon-nitrogen bonds. These studies were directed toward the development of a method for the iridium catalyzed N-alkylation of alpha-amino acid esters as well as the development of a strategy for synthesis of the natural product 275A.
We have optimized a method for the N-alkylation for alpha-amino acid esters. Using this method, we ...
C(Sp2)–H Functionalizations Employing 2-Aminophenyl-1h-Pyrazole As A New Removable Directing Group, 2017 The University of San Francisco
C(Sp2)–H Functionalizations Employing 2-Aminophenyl-1h-Pyrazole As A New Removable Directing Group, Wan-Chen Lee
2-Aminophenyl-1H-pyrazole (2-APP) was discovered as a novel removable bidentate directing group for copper-mediated aerobic oxidative C(sp2)–H bond amidation and sulfonamidation bearing a wide range of sulfonamides, When Cu(OAc)2 was employed as the copper source, 1,1,3,3-tetramethylguanidine (TMG) as an organic base, the reaction, optimally carried out overnight in DMSO at 80 °C in open air, produced a variety of products in moderate to excellent yields. In addition, C(sp2)–H bond chlorination has been developed by using this auxiliary, employing trichloroacetamide as a new chlorine source. Furthermore, this unprecedented directing group also can assist ...
Synthesis Of Pyranobenzopyrans, 2017 Seton Hall University
Synthesis Of Pyranobenzopyrans, Sumiea B. Eltayeb
Seton Hall University Dissertations and Theses (ETDs)
Carbohydrates and their derivatives are involved in a wide array of biological processes and are crucial for the survival of living entities. As a result, sugar-based compounds have become attractive scaffolds for drug design. In addition, pyranobenzopyran derivatives have shown promise in the treatment of numerous health conditions such as anticoagulants, antifungal, and anti-inflammatory agents. They have also shown important properties as antibiotics anti-AIDS agents) and antitumor drugs. The main point of our research was to determine and develop a synthetic method for the preparation of pyranobenzopyrans and carbohydrate fused heterocyclic compounds. This was accomplished via a [4+2] cycloaddition ...
Oxidative C-C Bond Formation Reactivity Of High Valent Nickel And Palladium Complexes, 2017 Washington University in St. Louis
Oxidative C-C Bond Formation Reactivity Of High Valent Nickel And Palladium Complexes, Michael Benjamin Watson
Arts & Sciences Electronic Theses and Dissertations
The development of both palladium and nickel catalysis over the past several decades has led to the ability to perform a multitude of C-C coupling, C-Heteroatom coupling, and C-H functionalization reactions. These reactions typically utilize a catalytic cycle involving Pd0/II/IV and Ni0/II. While using these types of catalytic cycles one can create a multitude of different hard to make bonds, it is always important to keep expanding what we view as potential catalytic intermediates to keep developing new cycles capable of new transformations.
One such way to expand our knowledge of these catalytic cycles is to look ...
Reactions Of Nitric Oxide With Beta-Hydroxylimino Esters, 2017 University of Wyoming
Reactions Of Nitric Oxide With Beta-Hydroxylimino Esters, Elayna M. Mahone
Honors Theses AY 16/17
Nitric oxide (NO) and its one electron reduction product nitroxyl (HNO) are known to act as vasodilators in mammals, including humans, and are considered a possible cure to cardiovascular diseases. However, their instability and high reactivity with atmospheric oxygen preclude the direct use of them as drugs. Recent work has shown that NO donor molecules can be used as pro-drugs to deliver NO to the appropriate bio-sites. Therefore, there is considerable research interest in the synthesis and studies of donors capable of releasing either of the molecules under physiological conditions.As part of our research effort towards the synthesis of ...
Substrate Analogs For Characterizing The Substrate Tolerance Of S. Pneumoniae Srta, 2017 Western Washington University
Substrate Analogs For Characterizing The Substrate Tolerance Of S. Pneumoniae Srta, Orion Banks
Graduate Student Conference
Bacterial sortases have been widely studied for their usefulness in protein modification, however, the variable substrate specificity and activity between homologs of these enzymes is not yet fully characterized. To attempt to further understand sorting signal recognition, we are working towards a substrate bound structure of sortase A from Streptococcus pneumoniae (SrtApneu). This enzyme displays a wide tolerance for alternate amino acids within the canonical LPXTG sorting motif. Our strategy involves a non-cleavable substrate analog that can be docked into the active site, allowing for elucidation of a structure displaying the key contacts that allow the enzyme to recognize ...
Genetically Encoded Fluorescent Protein Biosensor For Nitric Oxide, 2017 University of Nebraska-Lincoln
Genetically Encoded Fluorescent Protein Biosensor For Nitric Oxide, Wenjia Zhai
Student Research Projects, Dissertations, and Theses - Chemistry Department
Nitric oxide (NO) is an important molecule in living cells for signaling, thus a specific sensor to detect its level in live cells is needed. Currently there are a few small molecule probes for the detection of NO. A common shortcoming of these probes is their unavoidable leakage from the target cells. In this project, I seek to develop a novel green fluorescent protein (GFP)-based biosensor to detect cellular NO. This GFP-based sensor is genetically encodable and can potentially avoid the possible false positive result due to the leakage. I synthesized an unnatural amino acid (unAA) and examined its ...
Synthesis And In-Vitro Cell Viability/Cytotoxicity Studies Of Novel Pyrrolobenzodiazepine Derivatives, 2017 East Tennessee State University
Synthesis And In-Vitro Cell Viability/Cytotoxicity Studies Of Novel Pyrrolobenzodiazepine Derivatives, John M. Jarrett
Undergraduate Honors Theses
Pyrrolobenzodiazepines (PBDs) are a group of naturally occurring compounds that were discovered in the cultures of Streptomyces in the 1960s. Some natural PBDs discovered in these cultures, such as anthramycin and sibiromycin, were shown to possess a broad spectrum of anti-tumor activity. Since cancer is still a leading cause of death globally, the development of novel anti-proliferative derivatives of PBDs is essential for human welfare worldwide. Further synthesis and structure-activity relationship (SAR) studies of the parent natural products and their tetracyclic analogs will lead to the discovery of drug candidates. In this work, thirteen PBD analogues were synthesized using no ...
Rate Acceleration Of Organocatalytic Ring-Opening Polymerization Rough The Application Of Bis- And Tris- ( Io)Urea H- Bond Donors, 2017 University of Rhode Island
Rate Acceleration Of Organocatalytic Ring-Opening Polymerization Rough The Application Of Bis- And Tris- ( Io)Urea H- Bond Donors, Samuel S. Spink
Senior Honors Projects
Well-defined and functionalized polymers have a wide variety of applications in biomedical studies. Advancements in the fields of drug delivery, microelectronics, and medical imaging, among other applications, are predicated upon the development of methods for the synthesis of precision polymers. Organocatalytic ring-opening polymerization (ROP) of cyclic monomers is an effective route to the production of polymeric materials, namely polyesters and polycarbonates, whose biodegradable properties make them a viable option in biomedical research. Arguably, H-bond mediated catalysts are among the most selective catalysts for ROP, giving rise to highly functionalized polycarbonates, well-controlled polymerizations, and other custom tailored applications. With respect to ...
Total Synthesis Of Barettin: Model Study Of Specialized Aldol Condensation To Directly Access Diketopiperazine Targets, 2017 College of William and Mary
Total Synthesis Of Barettin: Model Study Of Specialized Aldol Condensation To Directly Access Diketopiperazine Targets, Elizabeth W. Kelley
Undergraduate Honors Theses
We synthesized (±)-(Z)-barettin, a potent anti-biofouler, with 31 % yield as a mono-TFA salt over seven steps with only one chromatographic separation. The route is efficient, proceeds under mild conditions, and is optimized to reduce formation of undesired byproducts otherwise seen in the aldol condensations and the Boc protection. Our route enables us to 1) utilize a DKP condensation with an unstable aliphatic aldehyde, 2) showcase how the DKP condensation provides direct access to a bioactive scaffold, and 3) suggest a simple, high yielding route to barettin and analogues consisting of only one chromatographic separation.
Inheritance Of Carbohydrates And Fat In Crosses Of Dent And Sweet Corn, 2017 Iowa State College
Inheritance Of Carbohydrates And Fat In Crosses Of Dent And Sweet Corn, E. W. Lindstrom, Fisk Gerhardt
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)
Dent and sweet varieties of corn (maize) are sharply differentiated in the chemical constitution of their seed, especially in relative amounts of sugars, dextrins, starches and fat. This fact, together with our knowledge of the mechanism of heredity in this species, provides an excellent background for an exact. determination of the mode of inheritance of these chemical characters. Another advantage in the genetic analysis, lies in the precise, cellular mechanism of double fertilization in the embryo sac whereby the endosperm tissue is developed as the result of a triple fushion of nuclei, two from the female and one from the ...
Synthesis Of Cyanine Dyes And Their Use As Duplex Dna Photocleavage Agents, 2017 Georgia State University
Synthesis Of Cyanine Dyes And Their Use As Duplex Dna Photocleavage Agents, Hector Argueta-Gonzalez
Georgia State Undergraduate Research Conference
No abstract provided.
Synthesis Of 1-Phenyl-3,5-Diaryl-4-Bromopyrazoles, 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromopyrazoles, And 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromoisoxazoles., Keren Antoine, Anne K. Jean, Roseleen Almenord, Sierra A. Fleming, Titilope Akinwe, Paula Garzon, Julio C. Falcon
Georgia State Undergraduate Research Conference
No abstract provided.
Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, 2017 Lynchburg College
Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, Jeff Brochetti
Student Scholar Showcase
Spectrofluorometric Analysis of Bisphenol-A in Drinking Water Bottles
Bisphenol-A (BPA) is of environmental concern due to its ability to act as an endocrine disruptor in humans and many other animals. In the food industry, BPA is widely used in the production of plastic bottles and plastic liners in aluminum cans. Over time, trace amounts of BPA can leach from the container and into the contents inside. A new method of testing for trace amount of BPA involved the formation of an inclusion complex with ß-Cyclodextrin. With the formation of the inclusion complex, it becomes much easier to analyze low concentrations ...
7Β-HydroxyArtemisinin, 2017 University of Mississippi
7Β-HydroxyArtemisinin, Paulo B. Carvalho, Bo Liu, Yunshan Wu, John S. Williamson, Mitchell A. Avery
John S. Williamson
Crystals of the title compound [systematic name: (3R,6R,7S,8aR,9R,12aR)-7-hydroxy-3,6,9-trimethyloctahydro-3,12-epoxy[1,2]dioxepino[4,3-i]isochromen-10(3H)-one], C15H22O6, were obtained from microbial transformation of artemisinin by a culture of Cunninghamella elegans. The stereochemistry of the compound is consistent with the spectroscopic findings in previously published works. A weak O—H⋯O hydrogen bond occurs in the crystal structure, together with intermolecular C—H⋯O hydrogen bonds.
Computational Modeling Of S-Thiolation Reaction: Toward Discovering The Enzymatic Mechanisms Of Endogenous Hno Formation, Elena Ivanova
Dissertations (2009 -)
S-nitrosothiols (RSNOs) have long been proposed as potential sources of the elusive endogenous nitroxyl (HNO) via S-thiolation reaction with thiols. It is however not clear how S-thiolation can compete with the trans-S-nitrosation pathway commonly observed in vitro. Based on the insights into the highly unusual, antagonistic chemical nature of RSNO molecules, we hypothesize that, while difficult in vitro, S-thiolation could easily lend itself to enzymatic catalysis. To explore this possibility, we adopted a bottom-up computational approach that aims to identify possible catalytic mechanisms able to steer the RSNO + thiol reaction toward HNO production. Inspired by recent discovery of small bioactive ...
Synthesis And Study Of The Electrochemical And Optoelectronic Properties Of Π-Conjugated Poly-P-Phenylene-Based Molecular Wires, Anitha Boddeda
Dissertations (2009 -)
Organic photovoltaics will play an important role in supplementing the energy needs of the twenty first century in a most cost-effective way to convert the solar energy into usable forms of energy. One of the bottlenecks in promoting widespread use of photovoltaic devices for solar energy storage is the inefficiency of the devices, which in part arises due to the inefficient charge separation and long-range charge transport. Design and synthesis of efficient charge-transfer materials would require one to first identify and establish the structural features necessary in a given molecular wire, which may promote effective charge transfer to long distances ...