Organic Chemistry Commons^™

Dynamics And Catalytic Resolution Of Selected Chiral Organolithiums, Timothy Kum Beng

Graduate Theses and Dissertations

One of the most important developments of the last decade has been the emergence of new methods to dynamically resolve racemic organolithiums using stoichiometric amounts of the chiral ligand. When this concept is implemented successfully, it obviates the need for covalently attached chiral auxiliary based methods, asymmetric deprotonation, and asymmetric synthesis of a precursor stannane as ways to access enantioenriched organolithium compounds for use in asymmetric synthesis. Since certain electrophiles consume the chiral ligand, it is desirable to render this process catalytic in the chiral ligand.

As part of a larger study on the amenability of chiral organolithiums to a …

Direct Contact Pyrolysis Of Hydrocarbons: A Source Of Hydrogen And Interesting Carbon Formations, Peter G. Faught

UNLV Theses, Dissertations, Professional Papers, and Capstones

The work detailed in this document looks at a novel liquid metal supported catalytic system for the generation of hydrogen by decomposition of ethanol through direct contact pyrolysis. The hydrogen is produced at relatively low temperatures (500-600°C) and has carbon and water as co-products. It should be noted that CO is not observed as a product at these low temperatures. This is to be contrasted with the hydrogen produced at higher temperature from ethanol which does contain carbon monoxide. The presence of carbon monoxide in hydrogen complicates fuel cell operation and catalytic chemical processes. Thus, the lack of CO in …

Organometallic Acene Complexes For Electronics Applications, Ilya Vinogradov

Kaleidoscope

No abstract provided.

Valine Sulfonamidecinnamic Acid Asymmetric Crystal Reactions, Kraig A. Wheeler, Steven H. Malehorn, Annie E. Egan

Faculty Research and Creative Activity

Racemic and homochiral valine sulfonamidecinnamic acidscrystallize with components aligned by use of thecomplementary features of hydrogen bonds and moleculartopology to give supramolecular dimers. These discretemotifs effectively organize adjacent olefins for UV initiated10 single-crystal-to-single-crystal [2+2] photodimerizationreactions. The racemic crystals produce inversion relatedcyclobutane products, while the desymmetrized crystallinearchitectures of the homochiral phase promote asymmetricphotodimerization with 90% conversion.

Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations: Synthetic Studies Directed Toward The Frondosins, Do W. Lee, Rajesh K. Pandey, Sergey V. Lindeman, William A. Donaldson

Chemistry Faculty Research and Publications

A short, 4-step route to the scaffold of frondosin A and B is reported. The [1-methoxycarbonyl-5-(2′,5′-dimethoxyphenyl)pentadienyl]Fe(CO)₃⁺ cation was prepared in two steps from (methyl 6-oxo-2,4-hexadienoate)Fe(CO)₃. Reaction of this cation with isopropenyl Grignard or cyclohexenyllithium reagents affords (2-alkenyl-5-aryl-1-methoxycarbonyl-3-pentene-1,5-diyl)Fe(CO)₃ along with other addition products. Oxidative decomplexation of these (pentenediyl)iron complexes, utilizing CuCl₂, affords 6-aryl-3-methoxycarbonyl-1,4-cycloheptadienes via the presumed intermediacy of a cis-divinylcyclopropane.

6-[(4-Hydroxyphenyl)Diazenyl]- 1,10-Phenanthrolin-1-Ium Chloride Monohydrate, Akram Hazeen, Yan Zhang, Minchong Mao, Kraig A. Wheeler, Mark E. Mcguire

Faculty Research and Creative Activity

In the cation of the title molecular salt, C18H13N4O+_Cl__H2O, the dihedral angle between the mean planes of the 1,10- phenanthroline system and the phenol ring is 14.40 (19)_. The crystal packing is stabilized by O—H_ _ _O hydrogen bonds, weak N—H_ _ _Cl and O—H_ _ _Cl intermolecular interactions and _—_ stacking interactions [centroid–centroid distance = 3.6944 (13) and 3.9702 (12) [A °]

Synthesis Of N-Acyl-N,O-Acetals From N-Aryl Amides And Acetals In The Presence Of Tmsotf, C. Wade Downey, Alan S. Fleisher, James T. Rague, Chelsea L. Safran, Megan E. Venable, Robert D. Pike

Chemistry Faculty Publications

Secondary amides undergo in situ silyl imidate formation mediated by TMSOTf and an amine base, followed by addition to acetal acceptors to provide N-acyl-N,O-acetals in good yields. An analogous, high-yielding reaction is observed with 2-mercaptothiazoline as the silyl imidate precursor. Competing reduction of the acetal to the corresponding methyl ether via transfer hydrogenation can be circumvented by the replacement of i-Pr₂NEt with 2,6-lutidine under otherwise identical reaction conditions.

An Integrated Systems Approach To Deconstructing Glycosylation, L. K. Mahal, John F. Rakus, Kanoelani Pilobello, P. Agrawal

Chemistry Faculty Research

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …

Synthesis And Structure Of A Substituted Pyridazine, Kiranmai Byrichetti

Masters Theses & Specialist Projects

Pyridazines are heterocyclic compounds with an N-N bond in their ring structure. Heterocyclic aromatic compounds are of great interest as a result of their novel properties and commercial applications. Our current research is focused on the potential role of pyridazines in next generation electronic devices that utilize organics as the semiconducting material. The synthesis of 5, 6-fused ring pyridazines beginning from fulvenes (Scheme 1) is described herein. These fused heterocycles will serve as synthetic models and building blocks for potential organic or organometallic conducting polymers.

Our goal was to modify the route of Snyder et al. previously reported for the …

Regiospecific Synthesis Of Ortho Substituted Phenols, Ravindra Kotha Balasainath

Masters Theses & Specialist Projects

Phenol is highly reactive toward electrophilic aromatic substitution. By this general approach, many groups can be appended to the ring, via halogenation, acylation, sulfonation, and other processes. Phenol contains the hydroxyl group (–OH), which is a strongly activating ortho/para directing group in aromatic electrophilic substitution (AES). AES gives a mixture of ortho-and para isomers, which must be separated.

The strong directing ability of phenol can also result in multiple substitutions on the aromatic ring which could be a major concern in the regiospecific synthesis of phenols. AES and Directed ortho--Metalation (DoM) are the only ways to directly substitute …

High Yield Synthesis Of Positron Emission Tomography Ligands For Metabotropic Glutamate Receptor Imaging, Saraanne E. Hitchcock

Department of Chemistry: Dissertations, Theses, and Student Research

Positron Emission Tomography (PET) is a powerful and non-invasive imaging technique used for human and animal organ imaging. Currently, the market for PET is project to reach $5.4 billion per year by 2015.5 This research focuses on the direct incorporation of [18F]-fluoride into PET ligands. The widespread use of PET imaging is currently frustrated, in part, by the lack of efficient fluorination chemistry.

Glutamate, one of the 20 most abundant naturally occurring amino acids, serves as a neurotransmitter in the central nervous system. Glutamate functions in this capacity by binding to ionotropic and metabotropic receptors. Metabotropic receptors are Gcoupled proteins …

Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum

All Dissertations

Ever since the discovery of conducting polymers (CPs)in the late 1970s, organic conjugated materials and polymers is one of the most popular and fascinating research area among the scientists due to the remarkably unique properties and broad range of applications of (CPs), notably organic photovoltaic (OPVs), organic or polymer based light emitting devices (OLEDs / PLEDs), field effect transistors (FETs), nonlinear optical (NLO) devices and sensor for biologically relevant analytes, metal ions and anions. Optical properties of these materials depend on intra / interchromophoric interaction, geometry and relative orientation in space. Detailed study of such materials can also help us …

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

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Fullerene-Based Organized Self-Assembled Photoactive Layer, Marcelo A. Yates ^, Danisha M. Rivera, Luis Echegoyen *

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Endohedral Derivatives For Bulk Heterojunction Organic Photovoltaic Devices, Gustavo Hernandez^, Michael D. Irwin*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Octaethyl-Nickel-Porphyrin Functionalized Silica For Fullerene Separation, Adriana Rodríguez^, Danisha M. Rivera, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Synthesis Of The Precursors For A New Covalent Organic Framework With Triangular Shaped Pores, Fernando J. Correa ^, Venkata P. Neti, Luis A. Echegoyen *

COURI Symposium Abstracts, Summer 2011

No abstract provided.

A Systems Approach To Understanding The Role Of Glycans In Cancer, John F. Rakus, Kaneolani T. Pilobello, Laura K. Mahal

Chemistry Faculty Research

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …

Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson

Chemistry Faculty Publications

Recent advances in lasers and detector technologies and the development of low-cost instruments and fiber-optic probes have brought about an explosion in the lubrication systems being studied by Raman spectroscopy. This article provides examples of the use of Raman spectroscopy in the study of lubrication phenomena, including the characterization of liquid lubricants, lubricant additives, and solid lubricants; the study of vapor-phase lubrication; and the use of coated nanoparticles as lubricants.

Insights Into Chemical Structure Changes Of Kerogen From Bituminous Coal In Response To Dike Intrusions Investigated By Advanced Solid-State 13C Nmr, Yuan Li

Chemistry & Biochemistry Theses & Dissertations

Variations in the chemical structures of kerogens From highly volatile bituminous coal located near two igneous dike intrusions in the Illinois Basin were examined in detail by advanced solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy. Spectral-editing techniques were used to identify specific functional groups. Direct polarization was used to quantify different functional groups. ¹H-¹³C two- dimensional heteronuclear NMR was used to examine connectivities and proximities, and ¹H-¹³C long-range recoupled dipolar dephasing was used to estimate aromatic cluster sizes. With decreasing distance to dike contacts and increasing thermal maturity (vitrinite reflectance R₀ from …