Adapting Chiral Gas Chromatography Into Existing Undergraduate Laboratories To Emphasize The Importance Of Stereochemistry,
2024
Bridgewater College
Adapting Chiral Gas Chromatography Into Existing Undergraduate Laboratories To Emphasize The Importance Of Stereochemistry, Ken Overway, Barnabas Otoo, Nicholas Griffin, Marshall Ritchie, Tyler Lynn, Kate Dear, Tyler Deutsch, Leigha Dillard
Chemistry Faculty Scholarship
Owing to the critical role of stereochemistry in biotechnology, medicine, and industry, it must be well represented in undergraduate lab curricula. To achieve these stereochemical laboratory requirements without sacrificing existing lab techniques, we modified two standard laboratory experiments to include chiral GC analysis as follows. (1) The extraction of carvone from spearmint leaves and caraway seeds via steam-distillation or other extraction methods is widely used in laboratories for analyzing the stereochemistry of the extracted products. The experiment was modified to include a GC method using a β-DEX 225 column. This allowed the students to compare the retention times of the …
Fluorescent Ph Indicators For Classroom Demonstration Of Buffer Action,
2024
Calvin University
Fluorescent Ph Indicators For Classroom Demonstration Of Buffer Action, Mark Muyskens, Mariana Dykstra, Yejin Chung
University Faculty Publications and Creative Works
We report an attractive update to the demonstration of acid−base buffer action that is appropriate for ease of use and getting attention in the classroom. The twist is based on new fluorophore information and the recent availability of UV flashlights serving as an ideal, portable excitation light source. The pH-dependent fluorescence comes from a choice among three natural sources, namely narra tree wood extract, kidneywood extract, and scopoletin, which is a purchasable coumarin, that all perform equally well. We provide practical details for performing the buffer demonstration at scales of 100 and 1000 mL and give background information for context
Research Trends And Impact Report On Aggregation-Induced Emission (Aie), 2001-2021,
2024
Analytical and Data Services, Elsevier
Research Trends And Impact Report On Aggregation-Induced Emission (Aie), 2001-2021, Elsevier Analytical Services
Public Reports
Since the concept of AIE was first proposed in China in 2001, it has gradually grown to a field of science that attracts dedicated researchers from around the world. Elsevier's data analytics team used AIE experts' interpretation of current theoretical, technological, and industrial development trends in the field for reference to collect AIE-related global scientific publications (from the Scopus database) to serve as a publication set in the field of AIE. This was undertaken to present, accurately and objectively, the development of AIE research over the past two decades and the latest scientific advancements in the field; to facilitate the …
Chemoselective Reduction Of Dicarboxylic Acids Via Iridium Catalyzed Hydrosilylation,
2024
University of Texas at Arlington
Chemoselective Reduction Of Dicarboxylic Acids Via Iridium Catalyzed Hydrosilylation, Linda Lallawmsangi
Chemistry & Biochemistry Theses - Archive
Reduction of esters to aldehydes poses a challenge since the resulting aldehydes are often more reactive than the initial esters toward nucleophilic hydride-reducing agents. Although bulky, more controllable reducing agents such as lithium tri-tert-butoxyaluminum hydride or diisobutylaluminum hydride (DIBAL-H) have been developed, they are hazardous, sensitive to moisture and air, needing strict reaction conditions, and unsuitable with a wide range of functional groups. We present the design of an iridium-catalyzed chemoselective hydrosilylation method for dicarboxylic imides, followed by hydrolysis to eliminate the amide and yield aldehydes. This approach offers versatility in general reduction chemistry, holds promise for application …
Synthesis Of Novel 5-Aryl 2’-Deoxyuridine And 2’-Deoxycytidine Analogues,
2024
CUNY City College
Synthesis Of Novel 5-Aryl 2’-Deoxyuridine And 2’-Deoxycytidine Analogues, Kevin E. Persaud
Dissertations and Theses
Briefly, the following report details a synthetic route to prepare 5-phenyl-2’-deoxycytidine analogues. This multistep synthesis began with silyl protection of the 3’- and 5’-hydroxyl groups of 5-iodo-2’-deoxyuridine. Next, the installation of a phenyl ring at the C5 position of the nucleobase via a Suzuki-Miyaura cross-coupling reaction, yielding 5-phenyl-2’-deoxyuridine (5-PdU). After that, modification of the obtained 5-PdU at the C4 position was performed with benzotriazole-1-yl-oxy-tris-(dimethylamino)-phosphonium hexafluorophosphate (BOP, a peptide-coupling agent) and a base (cesium carbonate) to activate the amide group of the uridine nucleobase for subsequent displacement with a variety of amines. Modification of the C4 position resulted in protected 5-phenyl-2’-deoxycytidine …
Advanced Detection Of Sars-Cov-2 And Omicron Variants Via Mxene-Graphene Hybrid Biosensors Utilizing Nucleic Acid Probes,
2024
Missouri University of Science and Technology
Advanced Detection Of Sars-Cov-2 And Omicron Variants Via Mxene-Graphene Hybrid Biosensors Utilizing Nucleic Acid Probes, Jiaoli Li, Yuwei Zhang, Congjie Wei, Yanxiao Li, Zhekun Peng, Hsin Yin Chuang, Logan Pearce, Adrianus Boon, Yue-Wern Huang, Dong Hyun Kim, Risheng Wang, Chenglin Wu
Biological Sciences Faculty Research & Creative Works
Low-cost biosensors that can rapidly and widely detect viruses are critical for faster diagnosis and treatment decision-making, especially for infections. The commonly used field-effect transistor is sensitive to the biomarker's detection but struggles with precise detection, particularly of nontargets such as ions and proteins. To overcome this limitation, we developed a field-effect transistor biosensor design based on MXene-graphene materials to increase the accuracy and sensitivity of virus detection. Based on the hybridization process between two complementary DNA strands, single-stranded nucleic acids were immobilized on the sensing surface via 3-aminopropyltriethoxysilane and glutaraldehyde to capture the nucleic acids of the target virus. …
Phenanthrene Jamboree,
2024
Colby College
Phenanthrene Jamboree, Alexander D. Roth
Honors Theses
Using cyclopropanated and cyclobutanated phenanthrene precursors, our hero embarks on a mission to find as many reactive intermediates as possible. Fraught with danger, romance, and mangosteens, Anderson calls this work 'monstrous' and 'alarming.'
Studies Towards High Surface Area Porous Polymers Via Cross-Coupling Methodology,
2024
Wayne State University
Studies Towards High Surface Area Porous Polymers Via Cross-Coupling Methodology, Anthony Lybrand
Wayne State University Theses
Porous polymers, known for their high internal surface area and robust chemical stability, are promising candidates for applications in gas storage, water purification, energy storage, and catalysis. The Yamamoto-type Ullmann reaction, known for yielding high porosity polymers, serves as a benchmark in this study. However, its limitations as a homocoupling reaction restricts the synthesis of ordered A-B type copolymers. This research addresses this challenge by investigating the use of cross-coupling reactions, particularly the Negishi reaction, to synthesize A-B type copolymers with reduced defectivity and enhanced surface area. The synthesis of fully-metalated intermediates and their subsequent polymerization are discussed in detail. …
Design, Synthesis, And Evaluation Of Class Iia Histone Deacetylase (Hdac) Inhibitors,
2024
Wayne State University
Design, Synthesis, And Evaluation Of Class Iia Histone Deacetylase (Hdac) Inhibitors, Lauren Nicole Kotsull
Wayne State University Dissertations
Histone deacetylase (HDAC) proteins are linked to disease states, including cancer, and have become important targets for therapeutic development. Many inhibitors have been developed to target HDAC proteins, including FDA-approved inhibitors Vorinostat (SAHA), Belinostat, Romidepsin, and Panobinostat. These inhibitors non-specifically influence most of the 11 metal-dependent HDAC isoforms, which might contribute to the side effects that patients experience during treatment. The lack of selectivity also diminishes the use of HDAC inhibitors as biomedical research tools. To address these drawbacks, the development of selective inhibitors has been heavily studied. Yet, reported inhibitors are predominantly selective for class I HDAC isoforms (HDACs …
Hybridization And Duplex Stability Of Peptide Nucleic Acid Containing An Azobenzene Switch,
2024
Georgia Southern University
Hybridization And Duplex Stability Of Peptide Nucleic Acid Containing An Azobenzene Switch, Carmen J. Velasquez
College of Graduate Studies: Theses & Dissertations
Light-driven molecular switches that can be turned on and off on demand have found many biological applications. For DNA, RNA, and synthetic derivatives, the switch can be used to interfere with a hybridization event with a complementary strand. To explore this potential, we have synthesized three light-sensitive PNA which have an azobenzene group (PNA-5azo5 and PNA-4azo4), and two azobenzene groups (PNA-2azo5azo2) as part of the PNA backbone. UV experiments were used to verify the conversion to the cis-isomer from the initial trans state for all of the single-stranded Azo-PNA ( PNA-5azo5, PNA-4azo4, and PNA-2azo5azo2) by irradiating at 365 nm …
Synthesis Of Chiral Amino Acids Via Direct Amination Of Diazo Ester With A Rhodium-Based Catalyst,
2024
Georgia Southern University
Synthesis Of Chiral Amino Acids Via Direct Amination Of Diazo Ester With A Rhodium-Based Catalyst, Steven J. Boyles
Honors College Theses
Amino acids are critical molecules within living organisms as they are the building blocks of proteins. In organisms, proteins serve as regulators of necessary processes, structural components in tissue, hormones, and neurotransmitters. Amino acid therapy is an emerging treatment in the medical field used to treat symptoms of diseases such as Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. Amino acid therapies have also shown promising effects when it comes to treating mood disorders and weight management. In order to increase the number of amino acids available and increase the potential treatments for other ailments, there is a drive to increase …
Dna Origami-Assisted Regioselective Organization Of Anisotropic Gold Nanotriangle Clusters,
2024
Missouri University of Science and Technology
Dna Origami-Assisted Regioselective Organization Of Anisotropic Gold Nanotriangle Clusters, Wenyan Liu, Prashant Gupta, Yuwei Zhang, Krishna Thapa, Srikanth Singamaneni, Risheng Wang
Chemistry Faculty Research & Creative Works
The manipulation of anisotropic nanoparticles, such as gold nanorods and nano prisms, has attracted great attention in nanotechnology due to their sensitive geometry-dependent properties. However. traditional synthesis and assembly methods for these particles face challenges in size uniformity and higher-order structuring. To address these limitations, this study presents a strategy using DNA origami triangles, not just as templates, but as encapsulating agents for gold nanotriangles (AuNTs). This method enables the construction of diverse nanoparticle clusters with precisely controlled distance and orientation. The formed clusters exhibit unique optical characteristics, demonstrated by UV-visible spectroscopy and supported by finite-difference time domain (FDTD) simulations. …
Unexpected Ring Opening Reactions, Solid-State Structures, And A Chemiluminescent Reaction,
2024
Wilfrid Laurier University
Unexpected Ring Opening Reactions, Solid-State Structures, And A Chemiluminescent Reaction, L Hiscock
Theses and Dissertations (Comprehensive)
Functional π-materials involve the use of an aromatic π-system to carry out a function such as electron transport (organic electronics), absorbing and emitting photons (dyes, fluorescent materials), self-assembly (discotic liquid crystals), or sensors for various analytes. Our lab has recently published the syntheses of heteroaromatic derivatives of tetrafluoroterephthalonitrile (TFTP, 2.24) synthesised via nucleophilic aromatic substitution chemistry. The prepared derivatives have displayed fluorescent (e.g. 2.2)1 and liquid crystalline (1.0)2 properties, as well as displaying close π-π interactions in the solid state (2.8).3 As the materials we are synthesising all belong to the class of aromatic compounds, an introduction to aromaticity and …
Additive-Dependent Regioselective Boracarboxylation Of Alkenes Using Low Valent Copper And Co2,
2024
West Virginia University
Additive-Dependent Regioselective Boracarboxylation Of Alkenes Using Low Valent Copper And Co2, Carly H. Gordon Ph.D.
Graduate Theses, Dissertations, and Problem Reports (ETD)
As a major greenhouse gas, carbon dioxide (CO2) is an abundant and renewable C1 feedstock, and developing methods for fixing CO2 into high-value products is a major interest for the movement of greener chemistry. The boracarboxylation of alkenes provides access to difunctionalized products containing pharmaceutically relevant motifs, including carboxylic acids and boron-containing moieties. Significant work has been done to improve the versatility and efficiency of this methodology, with the recent expansion into a wide variety of terminal alkenes. The use of different phosphine and alkene additives have demonstrated positive effects on reaction rates and productivity, indicating …
Room Temperature Decarboxylative Amination Reactions Of Carboxylic Acids,
2024
West Virginia University
Room Temperature Decarboxylative Amination Reactions Of Carboxylic Acids, Rabina Basnet
Graduate Theses, Dissertations, and Problem Reports (ETD)
Anilines are important structural motifs present in numerous natural products and pharmaceutically relevant compounds. Among the various synthetic strategies that have been developed, transition-metal-catalyzed cross-coupling reactions represent one of the most commonly employed methods for the formation of anilines. However, these approaches generally require pre-functionalized aryl coupling partners, and the utilization of more readily available, and structurally diverse coupling partners, such as carboxylic acids, would be desirable. Decarboxylative coupling reactions have garnered significant attention as an alternative approach to form new C-N bonds, and substantial progress has been made in this area. Nevertheless, these methods remain limited, with a predominant …
Α-Hydroxy C–H Functionalization Of Alcohols Via Boronic Acid, Hat, Photoredox Triad Catalytic System,
2024
West Virginia University
Α-Hydroxy C–H Functionalization Of Alcohols Via Boronic Acid, Hat, Photoredox Triad Catalytic System, Seth Christopher Cowan
Graduate Theses, Dissertations, and Problem Reports (ETD)
This dissertation explores the research that I have conducted in my time at West Virginia University. Most of my work has focused on the development of methods and studies to further understand the α-OH C–H functionalization of alcohols. This work involves a system of catalysts including photocatalysts, HAT catalysts, and boronic acid catalysts. Chapter 1 highlights a background for each of these areas. Photoredox catalysis has been an increasing area of chemistry over the past two decades as this technique can be used to design conditions to form new bonds in a selective manner through the utilization of light energy. …
Nickel-Catalyzed Regioselective Three-Component Coupling Of Phenyl Vinyl Sulfones With Alkynes,
2024
West Virginia University
Nickel-Catalyzed Regioselective Three-Component Coupling Of Phenyl Vinyl Sulfones With Alkynes, Stephen M. Long
Graduate Theses, Dissertations, and Problem Reports (ETD)
Benzene rings are some of the most prevalent motifs found in small molecule drugs with only a few dominant substitution patterns, 1-, 1,2-, 1,4-, and 1,2,4-. Nucleophilic aromatic substitution and electrophilic aromatic substitution are traditional methods for the synthesis of substituted benzenes and are robust and commonly used by chemical manufacturers, which explains in part the observed distribution of substitution patterns. Current methods to access substituted benzenes comprise of transition-metal-catalyzed C-H activation, transition-metal-catalyzed cross-coupling, and aryne chemistry. In general, the present methods require directing/leaving groups in specific positions to proceed, which inherently puts a limitation on substrate scope. Transition-metal-catalyzed [2+2+2] …
Chemical Synthesis And Biological Application Of Sensitive Rna,
2024
Michigan Technological University
Chemical Synthesis And Biological Application Of Sensitive Rna, Alexander T. Apostle
Dissertations, Master's Theses and Master's Reports
In the field of epigenetics - the dynamic collection of chemical modifications that overlay DNA/RNA - there is increasing interest in the potential for therapeutic and research-based utilization of the epitranscriptomics: those epigenetic modifications specific to RNA. Epitranscriptomics can give us a new approach to understanding and treating RNA viruses, like SARS-CoV-2. Given viruses are often found modified by human epitranscriptomic machinery, understanding how these modifications can modulate virulence is of high interest. We have shown that the N1-methyladensoine modification causes RNA synthesis termination in the SARS-CoV-2 replication complex, and thus may explain the differences in symptoms observed in individuals. …
Extraction Of Capsaicin Using The Polyol Induced Extraction (Pie) Method,
2024
Governors State University
Extraction Of Capsaicin Using The Polyol Induced Extraction (Pie) Method, Orlando Herrera
All Student Theses and Dissertations
Polyol-induced extraction (PIE) is an extraction technique for separating organic solvents from water, using glycerol and polyol as separating agents. Glycerol binds water releasing the organic solvent as a separate liquid phase. this thesis, investigates how the PIE process may be used to separate caffeine and capsaicin. When acetonitrile and water are used as a 1:1 solvent mixture, two immiscible phases are created upon addition of the polyol, glycerol. Initially, for purposes of training on the PIE method, the studies primarly began with the extraction of pure caffeine. Using a 1:1 mixture of acetonitrile and water, 20 m/v % glycerol, …
Green Oxidation Of Aromatic Hydrazide Derivatives Using An Oxoammonium Salt,
2024
Thomas Jefferson University
Green Oxidation Of Aromatic Hydrazide Derivatives Using An Oxoammonium Salt, Nidheesh Phadnis, Jessica A. Molen, Shannon M. Stephens, Shayne M. Weierbach, Kyle M. Lambert, John A. Milligan
Chemistry & Biochemistry Faculty Publications
Aromatic diazenes are often prepared by oxidation of the corresponding hydrazides using stoichiometric quantities of nonrecyclable oxidants. We developed a convenient alternative protocol for the oxidation of aromatic hydrazides using Bobbitt's salt (1), a metal-free, recyclable, and commercially available oxoammonium reagent. A variety of aryl hydrazides were oxidized within 75 min at room temperature using the developed protocol. Computational insight suggests that this oxidation occurs by a polar hydride transfer mechanism.
