Identifying Low-Coverage Surface Species On Supported Noble Metal Nanoparticle Catalysts By Dnp-Nmr, 2017 Iowa State University
Identifying Low-Coverage Surface Species On Supported Noble Metal Nanoparticle Catalysts By Dnp-Nmr, Robert L. Johnson, Frederic A. Perras, Takeshi Kobayashi, Thomas J. Schwartz, James A. Dumesic, Brent H. Shanks, Marek Pruski
Brent H Shanks
DNP-NMR spectroscopy has been applied to enhance the signal for organic molecules adsorbed on γ-Al2O3-supported Pd nanoparticle catalysts. By offering >2500-fold time savings, the technique enabled the observation of 13C–13C cross-peaks for low coverage species, which were assigned to products from oxidative degradation of methionine adsorbed on the nanoparticle surface.
Developing Functionalized Peroxide Precursors For The Synthesis Of Cyclic And Spirocyclic Ethers, 2017 University of Nebraska-Lincoln
Developing Functionalized Peroxide Precursors For The Synthesis Of Cyclic And Spirocyclic Ethers, Anna J. Diepenbrock
Student Research Projects, Dissertations, and Theses - Chemistry Department
There is increasing interest in the development of methods for the synthesis of oxetanes and spirocyclic oxetanes, a class of molecules of interest to chemists as they synthesize libraries of possible drug target scaffolds with tunable physiochemical and biological properties.1,2 Although most ethers are prepared through reaction of nucleophilic oxygen with electrophilic carbon, this work explores new reagents and routes for the synthesis of spirocyclic oxetanes based upon an application of "umpolung" or polarity reversal involving attack of nucleophilic carbon on the electrophilic oxygen of a peroxide (Scheme 1). In this work, a 2-carbon peroxide synthon for reverse ...
Development Of An Improved Synthesis Of S-D-Ribosyl-L-Homocysteine (Srh) And Progress Toward Srh Analogs Modified At The C3 Position, 2017 The University of San Francisco
Development Of An Improved Synthesis Of S-D-Ribosyl-L-Homocysteine (Srh) And Progress Toward Srh Analogs Modified At The C3 Position, Emily Rouse
Quorum sensing is a system that facilitates bacteria turning on and off gene expression depending on population density. System 2 quorum sensing is utilized by both Gram positive and Gram negative bacteria, and the quorum sensing molecule used in this system is AI-2. AI-2 is biosynthesized by the enzyme LuxS from the precursor SRH. This thesis describes an improved synthesis of SRH through the exploration of different protecting group strategies. The knowledge gained from the improved synthesis of SRH is then applied toward the synthesis of SRH analogues with increased steric bulk installed through use of a stereoselective anti-Mannich reaction ...
Tunable Copper Complexes For Sustainable Photocatalysis, 2017 Murray State University
Tunable Copper Complexes For Sustainable Photocatalysis, David Kline
Photoredox catalysis has direct applications in sustainable chemistry and thus an immense impact on our environment. With the ability to harness energy directly from the sun to catalyze useful chemical reactions, photocatalysts can help to eliminate the need for harsh reaction conditions and reduce generation of hazardous chemical waste. Photocatalysts based on Earth-abundant metals such as copper have recently emerged as sustainable alternatives to rare-earth metals including iridium and ruthenium, which are no longer required for many photocatalyzed chemical transformations.
Progress Toward Phidianidine Analogues Containing A 1,2,3-Triazole Ring, 2017 Coastal Carolina University
Progress Toward Phidianidine Analogues Containing A 1,2,3-Triazole Ring, David Laws Iii, Dillon King, Bryan H. Wakefield
Journal of the South Carolina Academy of Science
Phidianidines are a class of compound that has been extracted from the sea mollusk Phidianis militaris. These compounds have been shown to exhibit a variety of useful properties such as antihistamine effects, anti-cancer activity, agonism of the µ-opioid receptor and neuroprotection. The biological activities are thought to be caused by the 1,2,4- oxadiazole ring found within the molecule. The goal of this project is to synthesize analogues of phidianidine that contain a 1,2,3-triazole instead of the 1,2,4 oxadiazole ring using a method that will allow for other regions of the molecule to be changed ...
Ensemble-Based Modeling And Rigidity Decomposition Of Allosteric Interaction Networks And Communication Pathways In Cyclin-Dependent Kinases: Differentiating Kinase Clients Of The Hsp90-Cdc37 Chaperone, 2017 Chapman University
Ensemble-Based Modeling And Rigidity Decomposition Of Allosteric Interaction Networks And Communication Pathways In Cyclin-Dependent Kinases: Differentiating Kinase Clients Of The Hsp90-Cdc37 Chaperone, Gabrielle Stetz, Amanda Tse, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
The overarching goal of delineating molecular principles underlying differentiation of protein kinase clients and chaperone-based modulation of kinase activity is fundamental to understanding activity of many oncogenic kinases that require chaperoning of Hsp70 and Hsp90 systems to attain a functionally competent active form. Despite structural similarities and common activation mechanisms shared by cyclin-dependent kinase (CDK) proteins, members of this family can exhibit vastly different chaperone preferences. The molecular determinants underlying chaperone dependencies of protein kinases are not fully understood as structurally similar kinases may often elicit distinct regulatory responses to the chaperone. The regulatory divergences observed for members of CDK ...
Spatial Mapping And Profiling Of Metabolite Distributions During Germination, 2017 Iowa State University
Spatial Mapping And Profiling Of Metabolite Distributions During Germination, Robbyn Anand, Adam D. Feenstra, Liza E. Alexander, Zhihong Song, Andrew R. Korte, Marna Yandeaue-Nelson, Basil J. Nikolau, Young-Jin Lee
Germination is a highly complex process by which seeds begin to develop and establish themselves as viable organisms. In this paper, we utilize a combination of GC-MS, LC-fluorescence, and mass spectrometry imaging (MSI) approaches to profile and visualize the metabolic distributions of germinating seeds from two different inbreds of maize seeds, B73 and Mo17. GC and LC analyses demonstrate that the two inbreds are highly differentiated in their metabolite profiles throughout the course of germination, especially with regard to amino acids, sugar alcohols, and small organic acids. Crude dissection of the seed followed by GC-MS analysis of polar metabolites also ...
Reintroducing Explicit Solvent To A Solvent-Free Coarse-Grained Model, 2017 Iowa State University
Reintroducing Explicit Solvent To A Solvent-Free Coarse-Grained Model, Seung Ha Kim, Monica H. Lamm
Monica H. Lamm
A unique coarse-grained modeling scheme that combines a systematic, solvent-free multiscale coarse-graining algorithm for a complex macromolecule with an existing coarse-grained solvent model is proposed. We show that this procedure efficiently and reliably describes the interactions for complex macromolecules, using the specific example of dendrimers binding phenanthrenes in water. The experimentally measured binding capacity is predicted by the unique coarse-grained modeling approach; the conditions for this simulation are beyond what could be reasonably simulated with an all-atom molecular dynamics simulation.
Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, 2017 Murray State University
Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, Sunny Kwan, Sunny Kwan
Honors College Theses
Polymers made from thiol-ene reactions are versatile – they can be made from a variety of easily obtainable starting materials and show promise as biomedical materials, hydrogels, resins, and nanoparticles. Ionic liquids (ILs) have uniquely exploitable physical and chemical properties, and polymerization of ILs into polymeric ionic liquids (PILs) enhances or changes these properties, allowing an even wider range of potential applications of ILs in technologies such as fuel cells, solar cells, and even artificial muscles. Bisimidazolium thiol-ene PIL (BITPIL) networks are polymers with each monomer consisting of two moles of bis-imidazolium bridged together with either an alkyl or poly(ethylene ...
Synthesis Of N-Heterocycles From Donor Acceptor Cyclopropanes And Progress Towards Flinderole A, B, And C, 2017 The University of Western Ontario
Synthesis Of N-Heterocycles From Donor Acceptor Cyclopropanes And Progress Towards Flinderole A, B, And C, Joanne E. Curiel Tejeda
Electronic Thesis and Dissertation Repository
The first chapter of this thesis describes two projects, one explores the novel reactivity of quaternary donor acceptor cyclopropanes and the second one involves progress toward the total synthesis of the flinderoles A, B, and C. The first project involves the Lewis acid catalyzed nucleophilic ring opening of quaternary donor acceptor cyclopropanes with indoline. It was found that the ring opening reaction worked well with either Sc(OTf)3 or Yb(OTf)3 as the Lewis acids. The ring opened products were also able to be converted into pyrroloindoles via a manganese (III) oxidative radical cyclization reaction. Cyclopropanes bearing alkynyl ...
Optimizing Synthesis Of Substituted Oxadiazole Based Liquid Crystal Compounds.Pptx, 2017 University of Puget Sound
Optimizing Synthesis Of Substituted Oxadiazole Based Liquid Crystal Compounds.Pptx, Blake Bordokas
Stereospecific Electrophilic Fluorination Of Alkylcarbastannatrane Reagents, 2017 The Graduate Center, City University of New York
Stereospecific Electrophilic Fluorination Of Alkylcarbastannatrane Reagents, Xinghua Ma
All Dissertations, Theses, and Capstone Projects
The introduction of fluorine atoms into organic molecules significantly changes their physical, chemical, and biological properties. Fluorinated organic compounds are used as pharmaceuticals, agrochemicals, materials, and tracers for positron emission tomography (PET). For example, the site-specific fluorination of drugs can block sites of phase I metabolism by cytochrome P450 enzymes as well as improve target-binding affinities. In view of the unique features of fluorine-containing compounds, there has been increasing interest in the development of novel methods for the synthesis of fluorinated molecules, especially the site-specific monofluorination of complex molecules. Herein, we present the enantiospecific conversion of chiral secondary alkylcarbastannatranes into ...
How To Be A Successful Organic Chemist, 2017 Portland State University
How To Be A Successful Organic Chemist, Alexander H. Sandtorv
PDXOpen: Open Access Textbooks
How to be a successful organic chemist is meant as an introductory text for undergraduates taking organic chemistry teaching labs. The text is a clear and practical introduction to safety, chemical handling, organic chemistry techniques, and lab reports.
Synthesis Of Healable Organic Semiconductor Through Dioxaborolane Bond, 2017 Purdue University
Synthesis Of Healable Organic Semiconductor Through Dioxaborolane Bond, Junchen Liu, William W. Mcnutt, Jianguo Mei
The Summer Undergraduate Research Fellowship (SURF) Symposium
The field of organic semiconductors have gained enormous attention the past few decades. Organic materials offer numerous advantages over their inorganic counterparts. Recently a number of works have demonstrated organic semiconductors with healable properties. We aim to investigate the healable ability of an organic semiconductor by mimicking a vitrimer system through the reversible dioxaborolane bond. Vitrimers are polymers with reversible crosslink system. It has been reported that the use of the borane-oxygen bond as the crosslink showed good mechanical performance. The electrical properties will be inspected for the vitrimer-like polymer. In this report we describe a Diketopyrrolopyrrole base polymer incorporating ...
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 ...
Enantioselective Γ- And Δ -Borylation Of Unsaturated Carbonyl Derivatives: Synthesis, Mechanistic Insights, And Applications., 2017 University of Nebraska-Lincoln
Enantioselective Γ- And Δ -Borylation Of Unsaturated Carbonyl Derivatives: Synthesis, Mechanistic Insights, And Applications., Gia L. Hoang
Student Research Projects, Dissertations, and Theses - Chemistry Department
Chiral boronic esters are valuable synthetic intermediates widely used in a variety of stereospecific transformations. Transition metal-catalyzed asymmetric hydroboration (CAHB) of alkenes is among the most popular methods for their preparation. Enantioselective hydroboration of activated alkenes (i.e., vinyl arene derivatives or conjugated carbonyl compounds) have been extensively studied by many research groups. We, on the other hand, are interested in enantioselective hydroboration of unactivated alkenes utilizing coordinating functional groups (e.g., carbonyl derivatives) to give functionalized, chiral boronic esters. While conjugate addition and C–H activation methodologies provide efficient alternatives to CAHB for enantioselective beta-borylation of carbonyl compounds, direct ...
The Functionalization Of N-Cyclobutylanilines Under Photoredox Catalysis, 2017 University of Arkansas, Fayetteville
The Functionalization Of N-Cyclobutylanilines Under Photoredox Catalysis, Jiang Wang
Theses and Dissertations
While transition metal catalyzed cross coupling reactions have become one of the most useful strategies in constructing carbon-carbon and carbon-heteroatom bond formations, major disadvantages such as high reaction temperature, expansive metal catalysts input and limited reaction substrates scope have significantly downshifted the applications of those two electron involved transformations. Comparably, the studies on the redox coupling reactions are less investigated. Derived from single electron transfer process, the redox coupling reactions can be used to construct otherwise challenging chemical bonds efficiently, such as Csp3-Csp3 bond. Recently, visible light mediated photoredox catalysis has merged as a highly prominent tool in the development ...
Electronic Structure Evaluation Of Competing Pathways In The Gold(Iii)-Catalyzed Ohloff-Rautenstrauch Cyclosimerization Converting Propargylic Acetates To Carene-Like Natural Products, 2017 Missori State University
Electronic Structure Evaluation Of Competing Pathways In The Gold(Iii)-Catalyzed Ohloff-Rautenstrauch Cyclosimerization Converting Propargylic Acetates To Carene-Like Natural Products, Jeremy M. Hines
MSU Graduate Theses
Propargylic acetates can lead to complex transformations upon exposure to a gold catalyst. Gold catalyzed transformations also allow for simple synthesis of a number of natural products. Gold (III)-cycloisomerization of a 5-acetoxy-1,6-enyne is reported to proceed through two pathways that differ in the order of major events: cyclization followed by ester migration (“cyclization first”) or the reverse (“migration first”). Both pathways could theoretically proceed in either order. This rearrangement is called the Ohloff-Rautenstrauch rearrangement and has high regio- and stereocontrol affording a bicylo[4.1.0]heptane carbon substructure. This rearrangement allows for the synthesis of the carene ...
Synthesis And Characterization Of Benzalkonium Salts As Potential Antimicrobial Agents, 2017 Clark Atlanta University
Synthesis And Characterization Of Benzalkonium Salts As Potential Antimicrobial Agents, Saad S. Alotaibi
Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University
One of the most significant classes of industrial chemicals is benzalkonium salts. Benzalkonium salts have application in large number of commercial products. Benzalkonium salts enhance cationic surface activity and this particular property results in the salts being useful biocides, detergents, and disinfectants. Their antimicrobial activities depend on the structure of the side alkyl chain. For instance, long alkyl chains of C12 were most effective against fungi, yeast, and ophthalmic solution, C14 were effective against gram-positive bacteria, and C16 were effective against gram-negative bacteria. To add them to the databank of structure activity relationships (SAR) of benzalkonium salts ...
Review: New Frontiers In Metabolomics: From Measurement To Insight, 2017 University of Nebraska-Lincoln
Review: New Frontiers In Metabolomics: From Measurement To Insight, Eli Riekeberg, Robert Powers
Robert Powers Publications
Metabolomics is the newest addition to the “omics” disciplines and has shown rapid growth in its application to human health research because of fundamental advancements in measurement and analysis techniques. Metabolomics has unique and proven advantages in systems biology and biomarker discovery. The next generation of analysis techniques promises even richer and more complete analysis capabilities that will enable earlier clinical diagnosis, drug refinement, and personalized medicine. A review of current advancements in methodologies and statistical analysis that are enhancing and improving the performance of metabolomics is presented along with highlights of some recent successful applications.