Organic Chemistry Commons^™

Synthesis, Characterization, And Redox Properties Of Select 1,4-Diazocine-6,11-Diones Towards An Electrochromic Dye-Set, Jeffrey Scott Richards

Open Access Theses & Dissertations

The daily consumption of personalized digital visual information depends on the current purview of electronic-based displays. Present manufacturers utilize modern technologies, such as LCD, OLED, QLED, and electronic ink, or "E Ink," in their devices to display text, pictures, and other forms of media to individual users. However, as modern society continues to rely on the use of digital displays, the demand for low-power alternatives will continue to rise as their application in varying scenarios is realized. Currently, "E Ink" technology continues to grow as the dominant solution in the e-readers and digital signage marketplace, and can even be seen …

Neoglycoproteins As Potential Biomarkers And Vaccines For Chagas Disease, Elisa Garcia Carvajal

Open Access Theses & Dissertations

Trypanosoma cruzi, the causal agent of Chagas disease (CD), currently affects 6-8 million people worldwide, predominantly in Latin America, where the parasite is endemic. The treatment of CD is based on two drugs, benznidazole (BZN) and nifurtimox (NFX). These drugs cause adverse effects and are more effective in the acute phase of the disease. Conventional serology assays can be used for diagnosis, but they are not suitable for determining chemotherapy effectiveness because patients take approximately 10-20 years to exhibit negative seroconversion. Although CD has become a global health problem, specific biomarkers are still needed for the follow-up of chemotherapy and …

Organic Synthesis For Solving Clinical Conundrums Of Drug Activation And For Facilitating Natural Product Drug Discovery, Elkin Libardo Romero

Open Access Theses & Dissertations

Organic chemistry is an exploratory world in which chemists translate their knowledge by creating new molecules and explore their biological and physical properties. For the past three years, our research has been focused on organic synThesis and chemical biology to solve challenges in this area. Two major approaches have been faced: First, the chemical synThesis of the active metabolite of antithrombotic prodrug Plavix (clopidogrel). Clopidogrel (CPG) has been widely used as an antithrombotic prodrug, which undergoes extensive metabolism in patients; among it, only a trivial portion is converted through a series of cytochrome P450 (CYP)-catalyzed thiophene degradation to form active …

Novel N-Derivatized-7-Nitroindolines For The Synthesis Of Photocleavable Crosslinkers, And For Solid Phase Peptide Synthesis, Hector Patricio Del Castillo

Open Access Theses & Dissertations

7-Nitroindoline-based photochemistry has focused mostly on N-acyl-7-nitroindolines, which have been used as photocleavable protecting groups for carboxylic acids that can be efficiently removed by illumination with UV-light. They offer an alternative to the more commonly used o-nitrobenzyl-based photocleavable protecting groups. N-acyl-7-nitroindolines can also be used as photochemical acylating agents in inert solvents. For example, they have found application in peptide fragment condensation, the convergent synThesis of N-glycopeptides, and the synThesis of peptide thioesters, forming amide and thioester bonds with amine and thiol nucleophiles, respectively, under neutral conditions. The photochemical activation of N-acyl-7-nitroindolines can occur with UV light (λ = 350 …

Ibuprofen As A Probe Of Lipid Metabolism, Jose Antonio Rosales

Open Access Theses & Dissertations

The hypothesis that deracemization of racemic ibuprofen (IBU) occurs via the enolization of a Candida rugosa lipase (CRL)-ibuprofen ester (Scheme 1.6.2) was disproven by reacting racemic IBU under the conditions that were used to deracemize ibuprofen methyl ester (IME), namely pH 7.6. At pH 7.6, IME through IBU butyl esters were not formed in-situ and racemic IBU was not deracemized by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL.

At pH 7.6, hexyl through dodecyl IBU esters were formed in-situ by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL. The …

Synthesis Of New Fullerene Derivatives For Photovoltaic And Biological Applications, Edison Castro

Open Access Theses & Dissertations

Functionalized fullerenes exhibit improved solubility and different chemical and physical properties that allow applications in multiple fields such as photovoltaic and biological applications. Currently, perovskite solar cells (PSCs) are the most rapidly developing type of solar cells with certified efficiencies rising from 3.8% in 2009 to 22.1% in 2016. The good electron transporting and solution processable properties of most fullerene derivatives make them the most popular electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs).

The work is reported in 11 chapters. We start with a fullerene overview followed by cleaver and elegant methodologies that allow the synThesis of …

Gravimetrically Characterizable Common Alkali Reducing Agents And Ligand Design Of A New Electron Rich Guanidinate, Efrain Maximiliano Castillo

Open Access Theses & Dissertations

SynThesis, isolation and characterization of 12 new alkali arenides was performed by the addition of the chelating base 18-crown-6. Electrochemistry, UV-vis/NIR spectroscopy and XRD studies were performed.

The incoorporation of an imidazolin-2-iminato group to the background of a guanidinate showed that this kind of ligand is electronically flexible and metal dependent. It was found that is more electron donating than some previously reported guanidinates and ketimine guanidinates.

Synthesis Of Neoglycoproteins/Neoglycopeptides And Their Immunological Evaluation In The Context Of Chagas Disease, Nathaniel Scott Schocker

Open Access Theses & Dissertations

The protozoan parasite, Trypanosoma cruzi, the etiologic agent of Chagas disease (ChD), has a cell surface covered by immunogenic glycoconjugates. A synthetic glycoarray containing non-reducing α-galactopyranosyl moieties related to mucin O-glycans of the parasite T. cruzi was evaluated by a chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) with sera from patients with chronic ChD, revealing the disaccharide Galα(1,3)Galβ as the immunodominant glycotope (Chapter 2). This disaccharide comprises the two terminal sugars of the known immunodominant glycotope Galα(1,3)Galβ(1,4)GlcNAcα, which is expressed on glycosylphosphatidylinositol-anchored mucins of the infective trypomastigote stage of T. cruzi and triggers high levels of protective anti-α-Gal antibodies (Abs) in infected …

Triphenylamine-, Porphyrin- And Fullerene-Based Derivatives For Photovoltaic And Other Applications, Danisha Marie Rivera Nazario

Open Access Theses & Dissertations

Proper collection of charges at the electrodes is an important process in organic solar cells. Interfacial layers between the electrodes and the photoactive layer have been design to improve charge collection and ohmic contacts. The most studied interfacial layer between the anode and the photoactive layer is the negatively charged polymer poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), that possesses good hole transporting ability. However, inhomogeneities at the surface of the electrode after deposition of the polymer lower the stability and performance of the OPV devices. Triphenylamine (TPA) derivatives have received increased attention in the organic solar cells (OSCs) field because of their favorable light …

Synthesis Of Benzofused-P-Indolequinones From 1,4-Naphthoquinone And Selective N-Debenzylation By Dess-Martin Periodinane, Quang Huynh Luu

Open Access Theses & Dissertations

p-Indolequinones are important heterocycles since they display interesting bioactivities such as anticancer activities as well as the ability to trigger drug release in drug targeting research. Additionally, they are also useful in precursors for the synThesis of bioactive compounds. Over decades, many methodologies have been investigated for the synThesis of p-indolequinones. Among those, cyclization of quinones plays an important role in convenient synThesis of these compounds. However, the great majority of these methods only describe quinones as electrophiles in cyclization. In our research, we found an intramolecular nucleophilic attack of quinone to an in-situ generated carbonyl group and developed a …

Isomerase Activity Of Candida Rugosa Lipase In Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, Saideh Sadat Mortazavi

Open Access Theses & Dissertations

The Candida rugosa lipase-catalyzed Dynamic Kinetic Resolution of racemic ibuprofen methyl ester was optimal at pH 7.6 to produce (S)-ibuprofen in 72 hours. The concentration of various buffers for these reactions ranged from 0.2 to 0.5 M. The commercial lipase was found to be acidic altering the final pH of the reaction mixtures. Dimethylformamide co-solvent maintained the reaction pH better than dimethylsulfoxide, with evidence of the latter functioning as an oxidizing agent. Lower concentrations of ibuprofen methyl ester and higher stirring rates led to faster conversions. The minimal amount of lipase needed was 20 mg/mL buffer. Reaction of (R)-ibuprofen methyl …

Synthesis Of Peptide-Α-Phenylthioesters Using A Solid Support With A Photoreactive Nitroindoline Moiety, Andrew Pardo

Open Access Theses & Dissertations

Peptide-alpha-phenylthioesters are particularly reactive starting materials for Native Chemical Ligation. Here we present a new photochemical method for the synThesis of peptide-alpha-phenylthioesters under neutral reaction conditions with various C-terminal amino acids. The peptides were synthesized by Fmoc strategy on Sieber amide resin with a photoreactive nitroindoline linker. After cleavage of the photoreactive and fully protected peptide from the beads with dilute trifluoroacetic acid an auxiliary nucleophile such as N-hydroxybenzotriazole or N-hydroxysuccinimide is used to photochemically generate the activated peptide ester in situ. Then thiophenol is introduced in the dark. This new method enabled us to synthesize peptide-alpha-phenylthioesters up to 21 …

Synthesis And Characterization Of Fluorophores For The Detection Of Lanthanides And Actinides, Robinson I. Roacho

Open Access Theses & Dissertations

A series of fluorophores based in the boron dipyrromethene (BODIPY) family were synthesized and characterized. These fluorophores have the capacity of being introduced to a carbamoyl methyl phosphine oxide (CMPO) lanthanide/actinide extractant. These blue, green and red emission fluorophores show high thermal/moisture stability and high fluorescence efficiencies. The fluorescence intensity seems to be dependent on the restricted rotation about the C(8)-C bond in 8-Ph-BODIPY. By taking advantage of this feature, a hydroxyl- containing BODIPY with high fluorescence intensity was synthesized to be incorporated to a CMPO carboxylic acid via esterification. Unfortunately, we did not observe an optical response upon the …

Photochemical Synthesis Of Amino Acid And Peptide Oxo-Esters, Alfredo Ornelas

Open Access Theses & Dissertations

Amino acid and peptide oxo-esters have played an important role in peptide chemistry for many years. Various amino acid esters are commonly used as protecting groups for peptide synthesis in solution. Moreover, activated phenyl ester derivatives have been used for chemical ligation of peptides. However, the synthesis of amino acid and peptide oxo-esters is commonly performed under acidic or basic conditions. Under acidic conditions, acid-sensitive protecting groups may be cleaved, and under basic conditions racemization of amino acid esters is a common problem. Here we present the photochemical synthesis of amino acid and peptide oxo-esters. Based on the photochemical properties …

Synthesis Of Methylene Γ-Lactones Using Carbon Dioxide, Bryan P. Ferrell, Shizue Mito, Giber Martinez, Intesar El-Feitouri

COURI Symposium Abstracts, Summer 2012

Many industrial processes generate the greenhouse gas, carbon dioxide, as a byproduct. Carbon dioxide can be captured and recycled by using it in organic synthesis to prepare beneficial compounds. The goal of this project is to develop a new method of synthesizing methylene γ-lactones using CO₂-metal complexes. Many gamma lactones are biologically active, and their synthesis is of importance to pharmaceutical and other industries. Allenes can react with a transition metal-CO₂ complex. It is proposed that a titanium metal complex prepared with an aldehyde will bind to an allene, and a seven-membered ring forms as CO_{2 …}

Synthesis Of Peptide Thioesters Without Loss Of Chiral Integrity, Renato A. Sousa, Andrew Pardo, Katja Michael

COURI Symposium Abstracts, Summer 2012

The chemical synthesis of polypeptides can be accomplished with a technique called Native Chemical Ligation (NCL), which requires two peptides, one with a C-terminal thioester and another one with an N-terminal cysteine. Conventional peptide thioester syntheses require coupling in the presence of organic bases, which can cause a serious epimerization problem, and consequently purification difficulties, as well as low reaction yields of the desired stereoisomer. There is a great need for alternative methods that avoid or minimize epimerization and preserve the chiral integrity of the C-terminal amino acid. The goal of this research is to demonstrate that a photochemical base-free …

Praseodymium Nitride Endohedral Metallofullerene As Donor In Photovoltaic Cells, Luis F. Gardea, Manuel N. Chaur, Luis Echegoyen

COURI Symposium Abstracts, Summer 2012

Trimetallic nitride template endohedral metallofullerenes (TNT EMFs) have been found to have structures and electronic properties that make them suitable for fields like molecular electronics. The particular compounds synthesized were the family of TNT EMFs Pr₃N@C_2n due to the relatively high yield of Pr₃N@C­₈₈ and even more due to its low first oxidation potential (0.06 V) and therefore this compound has the ability to act as a capable electron donor in a multilayer organic photovoltaic cell. The compound was synthesized through the use of a Kratschmer-Huffman arc reactor. A mixture of Praseodymium Oxide and …

One-Pot Γ-Amino Acids Synthesis From Co2 Via Zirconacycle, Teresita J. Maldonado, Diego A. Pedroza, Shizue Mito

COURI Symposium Abstracts, Summer 2012

One-pot γ-amino acids synthesis from CO₂ via zirconacycle was studied. It has been reported that ketone and isocyanides are viable substrates for insertion into Zr‒C bonds of zirconocene‒1-aza-1,3-diene complexes. The purpose of this project is to explore the viability of CO₂ insertion to develop a new method for γ-amino acids synthesis in which all the reactions are executed in a single pot. In this method, first zirconocene‒1-aza-1,3-diene complex is prepared by using Cp₂Zr₂Cl₂ and an α, β-unsaturated imine. Second, CO₂ was introduced into the zirconocene complex solution to form the seven-membered ring …

Development Of A New Protecting Group For N-Acetylneuraminic Acid In Glycopeptide Synthesis, Luis A. Barrera, Katja Michael

COURI Symposium Abstracts, Summer 2012

N-acetylneuraminc acid (Neu5Ac) is contained in a tumor-associated antigen called STn, which is expressed in form of glycoproteins on the cell surface of many carcinomas. Synthesized partial sequences (glycopeptides) of these cell surface glycoproteins could potentially be used as anticancer vaccines, or for the production of antibodies which could be useful for immunotherapy. STn-containing glycopeptides are sensitive to acid and base catalyzed decomposition, which makes their chemical synthesis quite challenging. If this research is successful, we may be able to contribute to the advancement of cancer research by making sensitive STn-containing glycopeptides more accessible through chemical synthesis.

My current project …

Synthesis Of Metal Organic Framework Composites For Improved Porosity, Jesse Murillo, Venkata P. Neti, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2012

The synthesis of new highly porous composite materials, by combining Metal Organic Frameworks (MOFs) and graphene derivatives is described. The porosity of these composite materials is confirmed by pore volume, nitrogen uptake, BET and Langmuir surface area calculations. Structural information for the composites is accomplished through powder x-ray diffraction measurements, thermal gravimetric analysis and scanning electron microscopy. MOF-210, reported by Yaghi et al. in 2010, was chosen for composition with a graphene oxide composite due to its record holding pore size and internal surface area. The synthetic route to creation of precursors for MOF-210, as well as MOF-210 synthesis, is …

Dye-Sensitized Solar Cells, Laiwu Chen, Agustin Molina Ontoria, Luis A. Echegoyen

COURI Symposium Abstracts, Summer 2012

A dye-sensitized solar cell (DSSC) is a low-cost device for converting solar energy and possesses a large-area, flexible, colorful and lightweight devices. It is based on a semiconductor (TiO₂) deposited on a layer of conductive ITO glass. The dye is placed over this semiconductor film, in contact with an electrolyte in order to close the circuit .

The crucial requirements for dye-sensitized solar cells are: (a) wide absorption spectrum; (b) the right anchor to the TiO₂, for instance -COOH; (c) match the energy of the LUMO level of the photosensitizer with the Fermi level of the …

Synthesis Of Palmitoyl Dihydroxyacetonephosphate, Merieme Khamsi, Igor C. Almeida, Katja Michael

COURI Symposium Abstracts, Summer 2012

The parasite Trypanosoma cruzi (T. cruzi) causes Chagas disease which is a big problem in Central and South America, affecting 16-18 million people annually. While there are two non-FDA approved drugs to treat acute Chagas disease, there is no treatment available for its chronic stage. The objective of this project is to synthesize the substrate for acyl dihydroxyacetonephosphate synthase (ADS). This enzyme participates in the first step of alkyl lipid synthesis which is very abundant in T. cruzi, and is a potential target for developing more efficient drugs or inhibitors to treat Chagas disease. Recently, several alkyl phospholipid derivatives …

Solar Synthesis Of Acyl Hydroquinones And Their Bioactivity., Fernando De Leon, Shizue Mito

COURI Symposium Abstracts, Summer 2012

Without the Sun, we would not enjoy the benefits of life here on the Earth. This energy is essential and crucial for sustaining life: playing important roles in circadian rhythms and photosynthesis in plants. In our research, this endlessly renewable clean energy source is utilized for photo-Friedel-Crafts acylation of 1,4 - benzoquinones and 1,4 - naphthoquinones. Photo-Friedel-Crafts acylation was first discovered in 1891 and although there have been reported examples of acylated products, the substrates are still limited. In this project a variety of aldehydes having different substituents are examined, and bioassays were performed. While conventional methods for photochemistry use …

Photo-Switched Interfacial Layers For Organic Solar Cell Applications, Catalina Suárez, Danisha M. Rivera-Nazario, Mahsa Hosseini, Luis Echegoyen

COURI Symposium Abstracts, Summer 2012

Structural and functional diversity have been incorporated in photo-switched donor-acceptor (D-A) systems for the development and improvement of Organic Photovoltaic Cells (OPVs). By varying the structure and electronic properties of the donor and acceptor, the length and electronic properties of the linker, it is possible to control the efficiencies and lifetimes of photo-induced intramolecular charge separated states (D⁺-A^-). Modification of electrodes is a widely studied field for applications in biochemistry, materials science, electrocatalysis, among others. Here we report for the first time the modification of gold (Au) and indium tin oxide (ITO) electrodes with fullerene-based dyads …

Ti2s@C78: A Non-Group-Iii Metal Sulfide Cluster Inside A C78 Cage, Vivian L. Triana, Fang-Fang Li, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2012

After the discovery of the first nitride cluster metallofullerenes (NCFs), Sc₃N@C₈₀, in 1999, numerous cluster metallofullerenes have been prepared. However, the types of “clusterfullerenes” reported so far are quite limited: nitride cluster fullerenes (NCFs), carbide cluster metallofullerenes (CCFs), oxide cluster metallofullerenes (OCFs) and sulfide cluster fullerenes (SCFs). Given that almost all of the encaged metals for all of these reported cluster fullerenes are limited to group-III (Sc, Y, and lanthanide) metals, there are very few reports of the synthesis of cluster fullerenes with a non-group III metal, titanium (Ti), trapped inside a carbon cage. However, the …

Synthesis Of Graphene/Mof-177 Composites, Nathaly Ortiz, Venkata P. Neti, Luis Echegoyen

COURI Symposium Abstracts, Summer 2012

Metal Organic Frameworks (MOFs) are formed by the self-assembly of metallic ions and organic ligands. These compounds have shown excellent properties for gas adsorption and catalytic activity. MOF-177 has one of the highest hydrogen storage capacities reported for porous materials at ambient temperatures (surface area = 3400m²/g), reported previously by Yaghi et al. Graphene and graphene based materials have unique structural, mechanical, and electronic properties. Graphene oxide(GO) and functionalized graphene have been used as support and as a structural pieces in the construction of MOF’s in the past. Synthesis of MOF-5 on the surface of GO and …

Novel Dyad-Fullerene Derivative Used As Acceptor With P3ht In Bulk Heterojunction Solar Cells, Amber D. Berkobien, Luis Echegoyen, Maira Cerón, Danisha Rivera

COURI Symposium Abstracts, Summer 2012

Within the world of solar cells, research is rapidly uncovering potential solutions to the alternative energy issues by utilizing bulk-heterojunction cell techniques (Figure 1a) for low-cost and quick effective manufacturing. In this scope of research, a unique concept of donor-acceptor (D-A) system pairing as an acceptor within the bulk-heterojunction cell has been brought to light; a new concept of utilizing HOMO/LUMO pairings to create effective transport systems between a combination D-A acceptor and polymer donor is being optimized for maximum Photo-Conversion Efficiency (PCE). Due to a similar band gap relationship between the commonly reported PCBM and the novel dyad fullerene …

Dibenzo(B,F)(1,4)Diazocine-6,11(5h,12h)-Dione Dianion. The Chameleon Compound, Ruben Fernandez^, Sergio Villanueva, Tomas Espinosa, James Salvador*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Photo-Friedel-Crafts Acylation With Sunlight, Fernando De Leon^, Shizue Mito*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Zirconium Mediated One-Pot Synthesis Of Γ-Amino Acids From Carbon Dioxide, Diego A. Pedroza^, Shizue Mito*

COURI Symposium Abstracts, Spring 2012

No abstract provided.