Since the discovery of molecular chirality in 1848, this notion has had a substantial impact on medicine, biology, and chemistry. Extensive effort has been directed towards the construction of chiral molecules that contain sp³ hybridized stereogenic centers. In contrast, less effort has been dedicated to molecules that are chiral by...
The first part of this manuscript is about the total synthesis of the Arundo donax bis(indole) natural products. The A. donax alkaloids were prepared using the first example of an ynindole Diels–Alder reaction. Each were then separated, isolated, and determined to have stable enantiomeric conformations at room temperature (Chen, J.;...
This dissertation describes the racemic and enantioselective synthesis cavicularin. Cavicularin is a macrocyclic bisbibenzyls family member natural product. It has been an attractive synthetic target due to its intriguing structure: the macrocyclic core imparts sufficient strain on the system to force one benzene rings to adopt a boat-shaped conformation, out...
The first part of this manuscript is about the total synthesis of the aspidosperma alkaloids leuconoxine, melodinine E and mersicarpine. Our synthetic strategy used a radical translocation-conjugate addition cascade to construct the core of the natural product. Specifically, a vinyl radical was generated from the homolysis of the C–I bond...
Organic compounds which contain one or more nitrogen atoms are especially important as they are disproportionately represented among biologically active molecules. As a result, significant effort has been focused on the development of methods for the synthesis of nitrogenous molecules. We identified the aminal as an under-explored functional group. Despite...
Aminal radical intermediates were generated by the method of radical translocation and reacted in C-C bond forming reactions with electronically deficient alkenes (Schiedler et al. Org. Lett. 2012, 14, 6092). Aminal radical intermediates can participate in inter- and intra-molecular reactions using both Bu3SnH and (TMS)₃SiH as hydride donors. Carbon–carbon bonds...
Aromatic heterocycles are core structural motifs in natural products, pharmaceuticals and biological polymers. Indoles, in particular, represent a significant subclass of aromatic heterocycles, both in terms of sheer numbers, but also in biological and pharmaceutical relevance. As such, new methodologies for the synthesis of indoles represent an important and continually...
Dearomatization reactions exist broadly in biosynthesis and chemical synthesis. The highly functionalized atoms of arenes can be masked by it aromaticity, and upon dearomatization, those reactive atoms can be readily applied to bond formation and further manipulation. The total synthesis of (–)-cephalotaxine and (–)- homoharringtonine is described via an oxidative...
Pharmaceuticals, molecular catalysts, and secondary metabolites often contain nitrogen. The problems faced synthesizing compounds which contain nitrogen was because of the Lewis base reactivity of nitrogen lone pairs, and the acidic protons of some nitrogenous functional groups. We developed two methods for the synthesis of nitrogeous compounds. Additionally, we successfully...
Substituted phenols are important substructures for pharmaceuticals, agrochemicals, natural products and biological probe molecules. The properties of phenolic molecules are substantially influenced by the substitution patterns of the phenolic ring. The chemical synthesis of phenols with various substitution patterns is an enduring challenge and multiple strategies have emerged. However, some...
Enantioenriched sp³-hybridized carbenoid reagents CR1R2MX (X = nucleofuge, M = electrofuge) of different types were investigated for the synthesis of polysubstituted alkyl chains by iterative stereospecific reagent-controlled homologation (StReCH) and for the stereospecific connective synthesis of alkenes by eliminative cross-coupling.
In the first part, putative enantioenriched α-chloroalkyllithiums (CHRLiCl) were employed...
The bimolecular reaction of two carbenoid species resulting in the formation of a carbon-carbon double bond (pi-system), referred to herein as carbenoid eliminative cross-coupling (CEXC), involves a series of three fundamental steps: (i) ate-complex formation (transmetalation), (ii) 1,2-metalate rearrangement, and (iii) beta-elimination. All three steps are stereospecific and so the...
Natural products have long been an important source of resources for humans. Many of these compounds possess unique chemical structures and potent biological properties. By targeting natural products with specific chemical properties, we can gain a better understanding of the roles these compounds play in the environment and their interactions...
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Supplemental figure 2.42. Mass spectra of the [M-H]- ions of collimonin C (2.24) or collimonin
The development of microfluidic devices for heavy metal extraction is presented in this dissertation. Various research areas, covering subjects from photochromic compound syntheses to microchip fabrication techniques are explored to develop microfluidic devices capable of extracting heavy metal ions from drinking water. Through integration of the beneficial characteristics of both...
Recently researchers have discovered that groups of small non-coding RNAs (ncRNAs) play regulatory roles in gene expression and participate in various biological processes. For example, pathogenesis of many diseases, cell cycle regulation, and signaling pathways. Intracellular and live cell imaging of small ncRNA groups will reveal their relative expression levels...
Traditional approaches for the direct preparation of alkenes are unable to fully control either the stereochemical configuration of the carbon-carbon double bond or else the regiochemistry of the substituents surrounding it. The recently introduced concept of carbenoid eliminative cross-coupling (CEXC) offers a remedy to these deficiencies by providing for a...
The synthesis of axially chiral polyfunctional derivatives of 8,8'-biquinolyl was explored and the catalytic action of appropriate derivative types investigated in three separate processes: (1) the silylcyanation of carbonyl groups and imines, (2) alkylation of a glycine Schiff-base via phase transfer-catalysis, and (3) direct amide bond formation from simple amines...
The study of natural products (NPs) and their application has shaped humanity. Starting with the idea of using plants as medicine, it has now grown into the science of purifying and identifying organic molecules from nature to study their inherent biological activities. Understanding the molecular structures of NPs is the...
β-chitin/chitosan extracted from newly utilized jumbo squid (Dosidicus gigas) pens were investigated in respect to their physicochemical properties, polymeric structures, deacetylation and depolymerization characteristics, and antioxidant and antibacterial activities. These functional properties were further compared with α-chitin/chitosan prepared from shrimp shells. Due to the low mineral content (< 1%) and...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
Complex organic transformations, such as the addition of pyrrole to ketene using planar chiral organocatalyst (*PPY), the four-component anhydride- Manniach reactions, and the site-selective desymmetrization of meso-1,2-diol, are remarkable synthetic reactions that provide high yield and high selectivity. However, the exact mechanism and origins of stereocontrol for theses synthetic organic...
Two distinct strategies were explored for the enantioselective synthesis of α-heteroatom substituted alkyl boronic esters by stereoselective reagent-controlled homologation using transient chiral carbenoid reagents CHYMX (Y = heteroatom, X = nucleofuge, M = electrofuge). In the first case, a stereospecific reagent-controlled homologation (sStReCH) approach to α-alkoxyalkylboronates using α-metalated S,O- and...
There has been a tremendous growth in interest in carbon nanodots (C-dots) in the past several years. As a nascent nanomaterial, C-dots have shown great promise in applications that benefit from their superior water dispersibility, low toxicity, non-blinking fluorescent output, chemical and biological compatibility, ease of functionalization and resistance to...
Analytical chemistry is an area of chemistry primarily focused on the study and use of instruments for separation, identification, and quantification of an analyte of interest. Specifically, separation science within analytical chemistry often refers to the process of dividing mixtures into their small component parts based on differences in their...
Altogether, this dissertation highlights the value of mass spectrometry-based analysis of intact proteins for solving problems related to understanding disease mechanisms and developing new therapeutics.
Mutations to the antioxidant enzyme Cu, Zn Superoxide Dismutase (SOD1) perturb protein structure in vivo to cause 2-5% of amyotrophic lateral sclerosis (ALS) cases. Metal-deficient...
The numerous different types of nanomaterials and paucity of reliable in vivo information on toxicity has resulted in enduring uncertainties associated with health and safety risks, thereby slowing progress in nanotherapeutic assessment and development. This dissertation explores how the embryonic zebrafish model can be applied to prioritize commonly used nanomaterial...
Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for...
Drosophila suzukii (Diptera: Drosophilidae) is an insect of global concern that causes serious damage to soft-skinned fruits. D. suzukii is widespread in North America, South America, Europe, and Asia and is listed as an invasive pest with strict quarantine protocols governing import and export. Given the damage caused by D....
Since the late 1990s accelerated growth in health care spending coupled with a cost shift of health insurance from employers to employees has created an increased financial burden for many families. Past research suggests that financial burden due to out-of-pocket (OOP) health care costs limits access to health care and...
Millions of U.S. households experienced hunger in 2005 and millions more experienced food insecurity. Previous research indicates that low-wage work and little social support contribute to food insecurity. Research also suggests that individuals cope by finding alternate food sources and drawing on social support. Further, researchers have found that rural...
In Part I, (4S,5R)-4,5-dimethyl-4-phenylcyclohex-2-enone (19a) was prepared in 73% yield with high enantio- and diastereo-selectivity (er > 98:2, dr > 20:1) on a multigram scale by a Yamada-Otani condensation between (E)-pent-3-en-2-one and 2-phenylpropanal catalyzed by a sulfonimide derivative of (S)-proline (18, HuaCat®). Synthetically useful transformations of the cyclohexenone product 19a...
The goal of this research was to determine if controlled atmosphere (CA) storage could be used to extend the market period of fresh Pacific Northwest blueberries and to evaluate the effects different storage atmospheres have on fruit quality. Furthermore, this research also investigated heat and mass transfer characteristics during cooling...
Ultrafast spectroscopy can exploit the structure-function relationship of chemical- and biological-based systems. More specifically, femtosecond stimulated Raman spectroscopy (FSRS) provides ground- and excited-state vibrational information with simultaneously high spectral (spatial) and temporal resolutions. The electronic counterpart, femtosecond transient absorption (fs-TA), complements FSRS data analysis as part of a comprehensive approach...
Studies toward the total synthesis of (+)-providencin (1), a highly oxygenated cembranoid dipterpene with a unique bicyclo[12.2.0]hexadecane skeleton and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 320 and 332 which contain all of the carbon atoms of 1. In a first generation approach...
The purpose of this phenomenological study was to explore the lived experiences and understandings of professionals engaged in the interpretation of archaeological resources and heritage sites. The focus was on the examination of the experiences of professionals engaged in the interpretation of archaeological resources and their understandings of the following:...
This dissertation is composed of three essays regarding the finite sample properties of estimators
for nonparametric models.
In the first essay we investigate the finite sample performances of four estimators for additive
nonparametric regression models - the backfitting B-estimator, the marginal integration M-estimator
and two versions of a two stage...
Organic semiconductors are of interest for (opto)electronic applications due to their low cost, solution processability, and tunable properties. Natural product-derived organic pigments have attracted attention due to their extraordinary environmental stability and unexpectedly good optoelectronic performance, in spite of only partially conjugated molecular structures. Fungi-derived pigments are a naturally sourced,...
Ultrafast spectroscopy has recently gained momentum as a powerful, noninvasive characterization toolset capable of studying a diverse array of samples with applications in chemistry, physics, biology, engineering, and more. Two popular ultrafast spectroscopic techniques include femtosecond transient absorption (fs-TA) and femtosecond stimulated Raman spectroscopy (FSRS). The latter of these techniques...
Part I: Racemic and asymmetric syntheses of a new substance with prospective antidepressant properties were achieved. In vitro assays with synthetic racemates (±)-25 and (±)-26 suggested that the former is a relatively selective inhibitor of serotonin transporter whereas the latter is a more balanced inhibitor of both serotonin and norepinephrine...
Porous carbon is indispensable in modern technology applications. It is used for energy storage, gas separation, water purification, catalyst support, and chromatography. The diversity of its applications stems from its unique properties, including high specific surface area, tunable pore volume, and chemical stability. Specifically, the large surface area provides high...
This study was conducted to determine if there were
possible areas of student individuality and uniqueness
that might contribute to successful completion of distance
education courses as compared to successful completion of
traditional classroom courses. Five areas of possible
differences were identified and studied: 1) differences
between the number of...
Aroma is one of the major components that determines the quality of wine and consumer acceptability. Fruitiness is a highly desirable aroma quality in white wines and has been well accepted by consumers across the globe. Tropical fruit aroma has been substantially studied in Sauvignon Blanc wines due to its...
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5. Figure 2.1. Example of the Polarized Projective Mapping sheet. Fixed poles: M =
melon, C
This dissertation incorporates coalition formation and probabilistic planning towards a domain-independent automated planning solution scalable to multiple heterogeneous robots in complex domains. The first research direction investigates the effectiveness of Task Fusion and introduces heuristics that improve task allocation and result in better quality plans, while requiring lower computational cost...
Technology is a key determinant of comparative advantage among nations. As information technology improves and the nations of the world become economically integrated, concern arises over the dissipation of high-income economies’ technological advantage. The three essays in this dissertation explore the trade and technology relationship, which is essential to economic...
The 158-year-old Commanding Officer's House at Fort Hoskins is one of only two such structures in Oregon representing the pre-Civil War era on the Western Frontier. From 1856-1861, it embodies a link in history between the prevailing ideology of western expansion and replication of Eastern cultural values into the frontier...
When it comes to carbohydrate, it has been assumed that only mono- and disaccharides, but not oligo- and polysaccharides, can be tasted. However, because of its importance in the human diet, oral detection of starch or its hydrolysis products would be beneficial. The main goal of this study was to...
Farmers and migrant and seasonal farmworkers (F/MSFW) dedicate their livelihoods to the production of food for consumers, yet they may struggle to access food to feed themselves. Rural residents, immigrants, and Hispanic/Latinx individuals all have higher risk for food insecurity, yet little is known about the unique contexts through which...
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C. Andersen Behavioral Model for Health Services Utilization