Organic Chemistry Commons^™

En Route Towards Α-Benzotriazoyl Nitroso Derivatives, Jean-Christophe M. Monbaliu, Lucas K. Beagle, Judit K. Beagle, Matthias Zeller, Christian V. Stevens, Alan R. Katritzky

Chemistry Faculty Publications

A new class of geminally-substituted nitroso compounds, i.e., α-benzotriazoyl nitroso derivatives, is presented. These compounds display a rather different behavior than other related nitroso compounds bearing a geminal electron-withdrawing group. An unexpected and spontaneous oxidation to the nitro analog is observed in solution.

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Graduate Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.

Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li

Graduate Theses and Dissertations

The bottom-up colloidal synthesis opened up the possibility of finely tuning and tailoring the semiconductor nanocrystals. Numerous recipes were developed for the preparation of colloidal semiconductor nanocrystals, especially the traditional quantum dots. However, due to the lack of thorough understanding to those systems, the synthesis chemistry is still on the empirical level. CdS quantum dots synthesis in non-coordinating solvent were taken as a model system to investigate its molecular mechanism and formation process, ODE was identified as the reducing agent for the preparation of CdS nanocrystals, non-injection and low-temperature synthesis methods developed. In this model system, we not only proved …

Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel

Graduate Theses and Dissertations

In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.

Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …

Data Mining Of Protein Databases, Christopher Assi

School of Computing: Dissertations, Theses, and Student Research

Data mining of protein databases poses special challenges because many protein databases are non-relational whereas most data mining and machine learning algorithms assume the input data to be a relational database. Protein databases are non-relational mainly because they often contain set data types. We developed new data mining algorithms that can restructure non-relational protein databases so that they become relational and amenable for various data mining and machine learning tools. We applied the new restructuring algorithms to a pancreatic protein database. After the restructuring, we also applied two classification methods, such as decision tree and SVM classifiers and compared their …

Synthesis Of Half-Loaded Nitroimidazole Indocyanine Green Dyes Attached To Carbon Nanotubes, Courtney L. Stanford

Master's Theses

Indocyanine green dye is the only FDA approved NIR fluorescent dye that can be used in humans. 2-Nitroimidazoles are very effective radiosensitizers, have low cytotoxicity, and target hypoxic tissue. By coupling the two together, hypoxic tumors can be targeted and imaged. Previous work has been done to couple 2-nitroimidazole to both sides of the indocyanine green dye. This work focuses on expanding that concept to couple 2-nitroimidazole to only one side of the dye, thus allowing for the other end to be available to couple to another compound, generating a half loaded 2-nitroimidazole indocyanine green dye. In theory, this half-loaded …

Fluorescence Tagging Of Marine Low Molecular Weight Carboxylic Acids, Brian C. Gismervik

Master's Theses

This thesis aims at the evaluation of the best amide bonding strategy that places a fluorescence aminomethyl coumarin tag onto a LMW organic acid in aqueous solution. A three-stage study was conducted. First, a suitable aminomethyl coumarin fluorophore was synthesized. Second, a library of acid-derivatized standards was synthesized for use in optimizing the anticipated HPLC separation of a mixture of LMW acids expected to be found in marine samples. Third, the aforementioned amide coupling strategies were screened to identify the most applicable method for our reaction conditions to the tagging of LMW organic acids in a large number of field …

Discrimination Of Colon Cancer Stem Cells Using Noncanonical Amino Acid, Xinrui Duan, Honglin Li, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells (CSCs) may be responsible for tumor recurrence. Metabolic labelling of newly synthesized proteins with non-canonical amino acids allows us to discriminate CSCs in mixed populations due to the quiescent nature of these cells.

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 …

Design, Synthesis And Evaluation Of Novel Diazirine Photolabels With Improved Ambient Light Stability And Fluorous-Based Enrichment Capacity, Arun Babu Kumar

USF Tampa Graduate Theses and Dissertations

Photoaffinity labeling is a quintessential technique in studying and analyzing the interaction between a ligand and receptor. Diazirines are one of the important photo-labile moieties used in photoaffinity labeling due to their superior photo labeling characteristics. Herein, we report the investigations we conducted with diazirine photolabels on (a) photochemical aspects leading to enhancement of their ambient light stability and (b) equipping them with fluorous tags to enable fluorous enrichment of labeled proteins. Furthermore, we report a pilot study to develop BACE-1 inhibitors, which have potential to be developed into photoaffinity probes.

3-Trifluoromethyl-3-phenyldiazirine offers good selectivity and protection against pseudolabeling but …

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 …