Chemistry Commons^™

Scandium Triflate-Catalyzed Aromatic Aldehydic C-H Activation, Nicholas Griffin

Honors Projects

Herein described is a scandium triflate-catalyzed C-H activation of commercially available aromatic aldehydes achieved in low yields. The reaction occured in a one-pot synthesis over a two-hour duration and required minimal purification. Inclusion of a fluorine-tagged phenol allowed for reaction monitoring via ¹⁹FNMR.

A Work Towards A Single-Bridge Hydrazine Sensor, Brenden Jay Schmeltz

Theses and Dissertations

Hydrazine can currently be detected by irreversible methods, Carbazolopyridinophane (2,18-Dithia[3][1,8]carbazolo[3][2,6]pyridinophane) CP was synthesized by Brown et al. to detect hydrazine in real-time while also being reversible. The threshold for detection was 100 ppb, regulatory use requires 10 ppb as this is when permanent damage to humans can be caused. A more sensitive sensor will allow for safer workplaces for many people. A single, 3-atom bridge sensor will further examine the photophysical capabilities of carbazole-pyridine as an emitter/quencher pair. 1-Carbazole-1-methylpyridyl-2methyl sulfide SBCP will allow freedom of rotation as well as the bending of the bridge. These benefits will introduce conformers which …

Investigations On Copper Assisted Oxidative Transformations For The Construction Of Diverse C-C/C-N(O) Bonds, Prasanna Kumari S

Theses and Dissertations

Copper catalyzed C-C, C-N/C-O bond formation reactions are a prominent tool to access diverse biologically relevant molecules. Herein, we present the copper- catalyzed diverse C-C/C-N(O) bond forming reactions. In Chapter-I (introduction), we briefly discussed the various copper mediated organic transformations with appropriate examples.

In Chapter II, we report a one-pot methodology for the vicinal aminoalkylation of naphthoquinone through a direct C(sp2)-H functionalization reaction. Through this method, readily available planar naphthoquinone substrates were transformed into three-dimensional molecular scaffolds through the formation of one C(sp2)-C(sp2) and two C(sp2)-N bonds. The indole fused nitrogen heterocyclic products were obtained in good yields. Apart from …

Alkaline Pretreatment And Air Mixing For Improvement Of Methane Production From Anaerobic Co-Digestion Of Poultry Litter With Wheat Straw, Yuanhang Zhan, Jun Zhu, Yiting Xiao, Leland C. Schrader

Biological and Agricultural Engineering Faculty Publications and Presentations

Alkaline pretreatment (AL) and air mixing (air) both have the potential to improve anaerobic co-digestion (Co-AD) of poultry litter with wheat straw for methane production. In this study, the effects of the combination of AL (pH 12 for 12 h) and air mixing (12 mL·d⁻¹) on the Co-AD process were investigated. The substrate hydrolysis was enhanced by AL, with soluble chemical oxygen demand increased by 4.59 times and volatile fatty acids increased by 5.04 times. The cumulative methane yield in the group of Co-AD by AL integrated with air (Co-(AL + air)), being 287 mL·(g VS_added) …

Singlet Oxygen-Mediated Conformational Flexibility, Antioxidant, And Isomerization Studies In Chemistry And Biochemistry, Oliver Turque

Dissertations, Theses, and Capstone Projects

Three chapters are included in this dissertation, each of which describes non-oxidative reactions, with peroxy intermediates formed between singlet oxygen (¹O₂) and substrate. (1) Novel discoveries related to the intermediate formed by ¹O₂ and dimethyl disulfane are explored. (2) A new mechanism is proposed, wherein the dihedral angle CS–SC (θ) determines the pro- or antioxidant activity of an organic disulfide. (3) A review of ¹O₂'s ability to facilitate the geometric isomerization of alkenes and polyenes is presented in Chapter 3.

Chapter 1 investigates the role of singlet oxygen potentially …

Synthesis Of Biologically Active Tropolones And Stereochemically Rich Compounds Via Cross-Coupling Reactions, Nana B. Agyemang

Dissertations, Theses, and Capstone Projects

Over the past years the Murelli lab has established research based on the synthesis and biological evaluations of alpha-hydroxytropolones (alpha-HTs). These seven-membered aromatic rings have three contiguous oxygen atoms that chelates to metals, thus, biologically having the ability to bind dinuclear metalloenzymes and promoting inhibition. Synthetic routes to alpha-HT’s are scarce and therefore has been the main driving force in developing efficient and general synthetic methods to obtain variations in alpha-HTs, enabling SAR studies. The Murelli lab have therefore developed an oxidopyrylium cycloaddition/ring-opening strategy that is able to generate polysubstituted alpha-HTs starting from kojic acid, a cheap and readily available …

Stereospecific Cross-Coupling Reactions With Enantioenriched Electrophiles, Iv Kraja

Dissertations, Theses, and Capstone Projects

We have developed a novel palladium-catalyzed stereospecific C(sp³)–C(sp³) Stille cross-coupling reaction between carbastannatrane nucleophiles and α-(trifluoromethyl) benzylic tosylates. This constitutes the first example of a stereospecific C(sp³)–C(sp³) cross-coupling reaction using an enantioenriched electrophile and an alkyltin nucleophile. This system has the potential to be extended to cross-coupling reactions using configurationally stable enantioenriched nucleophiles, thus enabling stereochemical control of two newly formed contiguous stereocenters. Generating enantioenriched α-(trifluoromethyl) benzylic compounds also has importance in pharmaceutical and agrochemical industries.

Through the development of this reaction, our findings show that the addition …

Syne1 Mutation Is Associated With Increased Tumor Mutation Burden And Immune Cell Infiltration In Ovarian Cancer, Laura M. Harbin, Nan Lin, Frederick R. Ueland, Jill M. Kolesar

Markey Cancer Center Faculty Publications

SYNE1, a nuclear envelope protein critical for cellular structure and signaling, is downregulated in numerous malignancies. SYNE1 alterations are found in 10% of gynecologic malignancies and 5% of epithelial ovarian cancers. Previous studies demonstrated an association between SYNE1 mutation, increased tumor mutation burden (TMB), and immunotherapy response. This study evaluates the SYNE1 mutation frequency, association with TMB, and downstream effects of SYNE1 mutation in ovarian cancer. Genetic information, including whole-exome sequencing, RNA analysis, and somatic tumor testing, was obtained for consenting ovarian cancer patients at an academic medical center. Mutation frequencies were compared between the institutional cohort and The Cancer …

Unleashing The Potential Of 1,3-Diketone Analogues As Selective Lh2 Inhibitors, Juhoon Lee, Hou-Fu Guo, Shike Wang, Yazdan Maghsoud, Erik Antonio Vázquez-Montelongo, Zhifeng Jing, Rae M. Sammons, Eun Jeong Cho, Pengyu Ren, G. Andrés Cisneros, Jonathan M. Kurie, Kevin N. Dalby

Markey Cancer Center Faculty Publications

Lysyl hydroxylase 2 (LH2) catalyzes the formation of highly stable hydroxylysine aldehyde-derived collagen cross-links (HLCCs), thus promoting lung cancer metastasis through its capacity to modulate specific types of collagen cross-links within the tumor stroma. Using 1 and 2 from our previous high-throughput screening (HTS) as lead probes, we prepared a series of 1,3-diketone analogues, 1−18, and identified 12 and 13 that inhibit LH2 with IC50’s of approximately 300 and 500 nM, respectively. Compounds 12 and 13 demonstrate selectivity for LH2 over LH1 and LH3. Quantum mechanics/molecular mechanics (QM/MM) modeling indicates that the selectivity of 12 and 13 may stem from …

Synthesis Of 2-Arylpyridines By The Suzuki–Miyaura Cross-Coupling Of Pyfluor With Hetero (Aryl) Boronic Acids And Esters, Juan Rueda-Espinosa, Dewni Ramanayake, Nicholas Ball, Jennifer A. Love

Pomona Faculty Publications and Research

The Suzuki–Miyaura cross-coupling of pyridine-2-sulfonyl fluoride (PyFluor) with hetero(aryl) boronic acids and pinacol boronic esters is reported. The reactions can be performed using Pd(dppf)Cl2 as the catalyst, at temperatures between 65 and 100 °C and in the presence of water and oxygen. This transformation generates 2-arylpyridines in modest to good yields (5%–89%).

Transition Metal-Catalyzed Functionalization Of Carbon-Hydrogen Bonds In Alkenes, Xiaolin Qian

Theses and Dissertations

Alkenes can undergo a variety of chemical reactions to form more complex molecules with a range of functional groups. This makes them useful starting materials for synthesizing a wide range of organic compounds. Chapter I provided an overview of the development history of alkenyl C−H bond activation. The early reactions of C−H compounds with metal complexes, as well as stoichiometric activation of the transition metal-activated C–H bond, were discussed. Then the first successful and efficient organometallic-catalyzed transformations of a C−H bond, the first transition metal-catalyzed vinylic C–H functionalization, and the first transition metal-catalyzed olefinic C–H functionalization under mild conditions were …

Improved Stoichiometric Synthesis Of Ccc-Nhc Pincer Rh Complexes And Catalytic Activity Towards Dehydrogenative Silylation And Hydrosilylation Of Alkenes, Enock Amoateng

Theses and Dissertations

N-Heterocyclic carbenes (NHCs) have attracted growing interest not only as successful ancillary ligands in a wide variety of transition-metal-catalyzed reactions but have also shown to offer photophysical and electrochemical properties. The metalation/transmetalation strategy using [Zr(NMe₂)₄] as initial metalating reagent offers an efficient approach to the preparation of CCC-NHC pincer complexes of the late transition metals such as Rh and Ir. In the process of investigating an intermediate and the mechanism of the metalation/transmetalation to Rh sequence, a mixed valent bimetallic CCC-NHC pincer Rh complex with two chloro ligands bridged between a [(CCC-NHC)Rh(III)] and a [Rh(I)(COD)] fragment …

[3+2]-Cycloadditions Of Tertiary Amine N-Oxides And Dipolarophiles Providing An Efficient Route To Heterocyclics And 1,2-Diamines, And Nickel Catalayzed Transformations, Sarah Hejnosz

Electronic Theses and Dissertations

Nitrogen containing compounds are ubiquitous in nature as well as pharmaceuticals. These structures exhibit rich bioactive and chemical properties boasting an array of practical applications. As a result, the synthetic methods of forming nitrogen containing compounds are highly sought after. More efficient syntheses of these structures could result in less expensive industrial processes, particularly in the pharmaceutical industry. Roussi and coworkers established a highly efficient synthetic route forming nitrogen containing heterocycles in a single step from commercially available reagents, however this chemistry has not be used since its discovery in the 1980. Herein, this work greatly expanded Roussi’s method and …

Activation Of The Renin–Angiotensin–Aldosterone System Is Attenuated In Hypertensive Compared With Normotensive Pregnancy, Robin C. Shoemaker, Marko Poglitsch, Hong Huang, Katherine Vignes, Aarthi Srinivasan, Cynthia Cockerham-Morris, Aric Schadler, John Anthony Bauer, John O'Brien

UK CARES Faculty Publications

Hypertension during pregnancy increases the risk of adverse maternal and fetal outcomes, but the mechanisms of pregnancy hypertension are not precisely understood. Elevated plasma renin activity and aldosterone concentrations play an important role in the normal physiologic adaptation to pregnancy. These effectors are reduced in patients with pregnancy hypertension, creating an opportunity to define the features of the renin–angiotensin–aldosterone system (RAAS) that are characteristic of this disorder. In the current study, we used a novel LC-MS/MS-based methodology to develop comprehensive profiles of RAAS peptides and effectors over gestation in a cohort of 74 pregnant women followed prospectively for the development …

Probing The Mechanism Of Dna Protein Crosslink Formation By Aziridinomitosenes Through The Selective Precipitation Of Protein Salts, Michael Blair

Boise State University Theses and Dissertations

Aziridinomitosenes are synthetic chemotherapeutic agents that are analogs of Mitomycin C, as well as other mitomycins. They are known for their ability to form DNA interstrand cross-links (ICLs), and more recently have been observed to form DNA-protein cross-links (DPCs). In this work, three synthetic aziridinomitsenes were prepared and studied to better understand the role of the C6 and C7 positions in the formation of DNA-protein cross-links. In addition, two separate methods, the advanced recovery of K-SDS precipitates and the K-SDS assays were utilized and compared to assess the advancements in the analysis of DPC formation. H AZM, C6 AZM, Dimethyl …

Synthesis And Reactivity Of Heteroatom Embedded Cycloalkynes In Spaac, Nickel Catalyzed Alkylarylation Of Alkenes, And Carbofluorination Of Alkynes, Namrata Khanal

Chemistry and Chemical Biology ETDs

Part I covers Chapters 1, 2, and 3

cycloaddition reactions, that is utilized in biorthogonal chemistry. This metal free version The strain promoted azide-alkyne cycloaddition (SPAAC) reaction is one of the popular 1,3-dipolar of click reaction offers advantage over copper catalyzed click reaction. Since it eliminates the use of copper that is toxic to cells, it is considered favorable for biocompatible reaction. Due to the increased reactivity with dipoles without the use of metal catalyst, cycloalkynes, in particular cyclooctynes, have been employed as the biorthogonal reagent in biorthogonal chemical reaction for the study of a biological processes in vivo. The …

Structures Of The Insecticidal Toxin Complex Subunit Xpta2 Highlight Roles For Flexible Domains, Cole L. Martin, David W. Chester, Christopher D. Radka, Lurong Pan, Zhengrong Yang, Rachel C. Hart, Elad M. Binshtein, Zhao Wang, Lisa Nagy, Lawrence J. Delucas, Stephen G. Aller

Markey Cancer Center Faculty Publications

The Toxin Complex (Tc) superfamily consists of toxin translocases that contribute to the targeting, delivery, and cytotoxicity of certain pathogenic Gram-negative bacteria. Membrane receptor targeting is driven by the A-subunit (TcA), which comprises IgG-like receptor binding domains (RBDs) at the surface. To better understand XptA2, an insect specific TcA secreted by the symbiont X. nematophilus from the intestine of entomopathogenic nematodes, we determined structures by X-ray crystallography and cryo-EM. Contrary to a previous report, XptA2 is pentameric. RBD-B exhibits an indentation from crystal packing that indicates loose association with the shell and a hotspot for possible receptor binding or a …

Extraction, Purification, And Characterization Of Potential Bioactive Compounds Produced By Janthinobacterium Lividum Tajx1901, Andy Elorm Agbakpo

Electronic Theses and Dissertations

Underexplored environments such as soil samples continue to be an untapped source of bacterial strains with great potential to produce secondary metabolites for medicinal applications. As a result, these microorganisms represent a broad and yet unknown reservoir of new strains capable of producing these novel compounds. The current research primarily seeks to perform the isolation, purification, and characterization of secondary metabolites from a soil bacterium (Janthinobacterium lividum TAJX1901). The isolated soil bacterium was successfully cultured on rich media agar plates, followed by extraction using methanol and chloroform. The purification methods utilized include flash column chromatography, preparative thin-layer chromatography, and …

Development And Applications Of Novel And Practical Fluorination Reagents., Yuhao Yang

Electronic Theses and Dissertations

The fluorine (F) atom has distinctive properties such as the highest electronegativity, small size, low polarizability, and strong C–F bond strength. Not surprisingly, fluorinated organic compounds have garnered significant attention in the pharmaceutical, agrochemical, and material fields. Since organofluorides are very rare in nature, we need fluorination reagents to help us transfer fluorine into the organic molecules. In past decades, a vast number of fluorination reagents have been developed and many of them are commercially available now. However, there is still much room for the improvement of these reagents. Our target is to develop novel and practical fluorination reagents to …

New Methodologies For Sustainable Organic Synthesis In Water., Sudripet Sharma

Electronic Theses and Dissertations

Water is stable, benign, and green solvent. Its usage as a solvent in organic synthesis is significantly enhanced by micellar catalysis. However, replacing water as a reaction medium in organic synthesis is not sufficient to meet the sustainability challenges—excessive organic solvents are still required for product isolation and purification. Notably, solvents used in syntheses contribute to more than 80% of waste generation. In addition to solvents, the use of palladium in large amounts is also a problem for the future as it is a precious, low-abundance metal, and its supply is dwindling. Therefore, this dissertation highlights the various sustainable protocols …

Composite And Polymer Formulation Employing Sulfur And Bio-Olefin Feedstocks, Claudia V. Lopez

All Dissertations

Environmental sustainability represents a challenge for society since industrial growth has a direct impact on natural resources and waste production. New technologies that effectively incorporate waste into renewable resources are critical to the development of a sustainable and circular economy. The manufacturing of structural materials like Portland cement (OPC) is responsible for >8% of the global anthropogenic emissions of carbon dioxide, with ~ 1 kg of CO₂ released to the atmosphere for every kilogram of OPC produced. For instance, the development of sustainable structural materials is a key factor to reduce the greenhouse emissions and to attenuate the climate …

Expansion Of The Diazacyclobutene Motif For Antiparasitic Evaluation, Brock Alexander Miller

All Dissertations

Molecules containing N-heterocycles are prevalent in pharmaceutical settings. The ability to generate highly functionalized molecules containing N-heterocycles in very few synthetic operations is valuable for drug discovery. Our group has developed a two-step synthesis to access a rarely studied diazacyclobutene scaffold via a formal [2+2] cycloaddition between 4-phenyl-1,2,4-triazolinedione and electron-rich thioalkynes. Our interest in this scaffold increased exponentially from promising preliminary biological evaluations against a protozoan parasite, Trypanosoma brucei. While we were able to double the number of historical examples of this scaffold, there were significant limitations in our methodology. The most notable limitations were the lack …

The Emergence Of Zerovalent Carbon Compounds From Structural Curiosities To Organocatalysts, Allegra L. Liberman-Martin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Low-valent main group compounds have reactivity patterns and properties reminiscent of transition metals. While divalent carbon compounds such as carbenes are widely studied ligands and organocatalysts, zerovalent carbon species have received considerably less attention. This perspective highlights the properties and reactivity of zerovalent carbon compounds, focusing on their first applications as organocatalysts for small molecule reduction and polymerization reactions.

Rhodium-Catalyzed Asymmetric Synthesis Of P-P And P-C Bonds, Sarah T. Chachula

Dartmouth College Ph.D Dissertations

Chapter 1: Synthesis, Structure, Dynamics, and Enantioface-Selective η3-Benzyl Coordination in the Chiral Rhodium Complexes Rh(diphos*)(η3-CH2Ph) Abstract: The rhodium benzyl complexes Rh(diphos*)(η3-CH2Ph) (1-14, diphos* = chiral bis(phosphine)) were prepared either by treatment of Rh(COD)(η3-CH2Ph) (15, COD = 1,5-cyclooctadiene) with diphos*, or from the reaction of [Rh(diphos*)(Cl)]2 (16- 20) with PhCH2MgCl. For C2-symmetric diphos*, observation of one set of NMR signals for complexes 1-12 suggested that the two diastereomers in which different 3-benzyl enantiofaces were coordinated to rhodium interconverted rapidly on the NMR time scale via suprafacial shifts; observation of five inequivalent aryl 1H NMR signals showed that antarafacial shifts were slow …

Scalable Preparation Of The Masked Acyl Cyanide Tbs-Mac, Haley Hinton, Jack Patterson, Jared Hume, Krunal Patel, Julie Pigza

Faculty Publications

This paper describes the three-step synthesis of TBS-MAC, a masked acyl cyanide (MAC) and a versatile one-carbon oxidation state three synthon. We have developed a scalable and detailed synthesis that involves: (1) acetylation of malononitrile to form the sodium enolate, (2) protonation of the enolate to form acetylmalononitrile, and (3) epoxidation of the enol, rearrangement to an unstable alcohol, and TBS-protection to form the title compound. Both the sodium enolate and acetylmalononitrile are bench-stable precursors to the intermediate hydroxymalononitrile, which can be converted to other MAC reagents beyond TBS by varying the protecting group (Ac, MOM, EE, etc.).

Synthesis Of Constrained N-Heterocyclic Peptidomimetics And Development Of Strain-Release Reagents, Kyle P. Pedretty

USF Tampa Graduate Theses and Dissertations

Part 1:The initial portion of this dissertation delves into the enhancement of β-sheet secondary structure stability through modification of the peptide backbone while examining the conformational characteristics of peptides featuring N-amino substituents. The investigation consists of two major studies, presented in separate sections. The first study outlines various approaches to achieve stable β-hairpin folds by introducing N-amino substituents to peptide strands. A novel method utilizing on-resin Mitsunobu cyclization between α-hydrazino acid residues and a serine or homoserine side chain was utilized to incorporate pyrazolidinone and tetrahydropyridazinone dipeptide constraints. To evaluate the impact of cyclic N-amino peptide building blocks on β-hairpin …

N–((2–Acetylphenyl)Carbamothioyl)Benzamide: Synthesis, Crystal Structure Analysis, And Theoretical Studies, Akin Oztaslar, Hakan Arslan

Karbala International Journal of Modern Science

N–((2–Acetylphenyl)carbamothioyl)benzamide has been synthesized and characterized. The molecular conformation of the investigated compound is stabilized by C16–H16B⋅⋅⋅O2ⁱ (i: 1+x, y, z) intermolecular and C14–H14⋅⋅⋅S1, N2–H2⋅⋅⋅O2, and N2–H2⋅⋅⋅O1 intramolecular H–bonds. All DFT calculations have been implemented at the B3LYP level with the 6–311G(d,p) basis set. The optimized molecular structure parameters have been compared with the experimental one in the solid phase. The energy gap, global chemical reactivity descriptor parameters, MEP, Fukui functions, DoS, NLO, and NBO analysis were also computed and investigated. The intermolecular interactions and their energies are evaluated using Hirshfeld surface and energy framework analyses. To determine …

Study Of Antioxidant Activity Of The Derivatives Of Quinoline-4-Carboxylic Acids By The Modification Of Isatin Via Pfitzinger Reaction, Sakti Hidayati Fikriya, Antonius Herry Cahyana

Makara Journal of Science

In this study, a quinoline-4-carboxylic acid derivative was synthesized through Pfitzinger reaction. In this reaction, isatin is modified via its reaction with ketone and refluxed for 24 h to obtain quinoline-4-carboxylic acid. The presence of a carboxylic group was identified by Fourier Transform Infrared (FTIR) spectroscopy and ultraviolet–visible (UV-Vis) spectrophotometry. The results showed that the absorption peaks of C=O and O–H stretching’s were detected in the range of 1724–1708 and 3436–3242 cm⁻¹, respectively. In the UV-vis spectrum, a shift in the absorption peak was observed toward a larger wavelength, which is referred as a bathochromic shift. The formation …

Study On Versatile S(Vi) Reagents Towards Synthesis Of S(Iv) And S(Vi) Functional Groups, Shun Teng

USF Tampa Graduate Theses and Dissertations

This dissertation mainly covers the latest methodology development in the field of sulfur-containing functional groups in synthetic chemistry. There are two parts. The first part is the asymmetric synthesis of sulfoximines, sulfonimidamides, sulfonimidoyl fluorides, and sulfinamides enabled by a versatile enantiopure S(VI) reagent. The second part is the Grignard reagent-triggered divergent S-editing synthesis via a bench-stable S(VI) reagent.

In the first part, the asymmetric synthesis of sulfoximines, sulfonimidamides, sulfonimidoyl fluorides, and sulfinamides is reported. This report focuses on the development of a bifunctional S(VI) reagent and its utility in synthesis. It employed the enhanced stability of sulfonimidoyl fluorides and the …

Investigation Of Challenging Transformations In Gold Catalysis, Qi Tang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) Divergent gold catalysis for alkyne trifunctionalization, encompassing three distinct modes to achieve the simultaneous formation of C-N, C-O, and C-C bonds in a single step 2) the study and development of a new method to synthesize azaborine derivatives; and 3) the construction of benzotriazole boranes (BTAB) as stable four-coordinate N-B heterocycles through gold-catalyzed alkyne hydroboration.

In the first part, alkyne trifunctionalization via divergent gold catalysis will be introduced. This novel approach involves a sequence of reactions that combine gold π-activation, vinyl gold nucleophilic addition, and gold (III) reductive elimination. By utilizing this methodology, …