Herbicides And Amphibian Populations,
2010
University of Nebraska-Lincoln
Herbicides And Amphibian Populations, Zach Shirk
Department of Environmental Studies: Undergraduate Student Theses
Amphibians are a unique class of species that are found worldwide except Antarctica and Greenland. They range in size from a few millimeters to over six feet long. Amphibian’s habitats are as various as their size, but one thing in common is that amphibians require an aquatic location to breed. Amphibians live in deserts, mountain prairies, rain forest, wetlands, and almost everywhere in between. Amphibians are an integrated part of most natural ecosystems across the world. Amphibians are a critical part of many food chains; they provide the important link between secondary and tertiary consumers. Amphibians are indicator species in …
Calculation Of Collisional Cross Sections For The ²P3/2 > ²P1/2 Transition In Alkali-Noble Gas Systems,
2010
Air Force Institute of Technology
Calculation Of Collisional Cross Sections For The ²P3/2 > ²P1/2 Transition In Alkali-Noble Gas Systems, Samuel D. Butler
Theses and Dissertations
Collisional cross sections were calculated as a function of energy for two coupled one dimensional, spherically symmetric potentials. The Split Operator Method was used to propagate an initial Moller state, chosen to be a Gaussian in the asymptotic limit, through a potential. The correlation between the wave packet and Moller final state was calculated at each time step. Using the Channel Packet Method, the correlation function was used to obtain scattering matrix elements. From scattering matrix elements for several different effective potential values and using the Method of Partial Waves, the collisional cross section is calculated for the transition from …
A Novel Choline Cotransporter Sequestration Compartment In Cholinergic Neurons Revealed By Selective Endosomal Ablation,
2010
Tennessee State University
A Novel Choline Cotransporter Sequestration Compartment In Cholinergic Neurons Revealed By Selective Endosomal Ablation, Michael T. Ivy, Robert F. Newkirk, Yilun Wang, James G. Townsel
Biology Faculty Research
The sodium-dependent, high affinity choline transporter – choline cotransporter – (ChCoT, aka: cho-1, CHT1, CHT) undergoes constitutive and regulated trafficking between the plasma membrane and cytoplasmic compartments. The pathways and regulatory mechanisms of this trafficking are not well understood. We report herein studies involving selective endosomal ablation to further our understanding of the trafficking of the ChCoT. Selective ablation of early sorting and recycling endosomes resulted in a decrease of ∼75% of [3H]choline uptake and ∼70% of [3H]hemicholinium-3 binding. Western blot analysis showed that ablation produced a similar decrease in ChCoTs in the plasma membrane subcellular fraction. The time frame …
2,3-Bis(Bromomethyl)-1,4-Diphenylbenzene,
2010
University of New Hampshire
2,3-Bis(Bromomethyl)-1,4-Diphenylbenzene, Jonathan B. Briggs, Mikael D. Jazdzyk, Glen P. Miller
Chemistry
In the title compound, C(20)H(16)Br(2), the terminal phenyl groups are twisted away from the central ring by approximately 55 and -125 degrees (average of four dihedral angles each), respectively. The crystal structure is stabilized by a combination of interMolecular and intraMolecular interactions including interMolecular pi-pi stacking interactions [C atoms of closest contact = 3.423 ( 5) angstrom].
Novel Photochemical Methodologies For Diversity Oriented Synthesis And Screening Of Combinatorial Libraries,
2010
University of Denver
Novel Photochemical Methodologies For Diversity Oriented Synthesis And Screening Of Combinatorial Libraries, Roman Askatovich Valiulin
Electronic Theses and Dissertations
The main goal of this project was to develop an efficient methodology allowing rapid access to structurally diverse scaffolds decorated with various functional groups.
Initially, we discovered and subsequently developed an experimentally straightforward, high-yielding photoinduced conversion of readily accessible diverse starting materials into polycyclic aldehydes and their (hemi)acetals decorated by various pendants. The two step sequence, involving the Diels-Alder addition of heterocyclic chalcones and other benzoyl ethylenes to a variety of dienes, followed by the Paternò-Büchi reaction, was described as an alkene-carbonyl oxametathesis. This methodology offers a rapid increase in molecular complexity and diversity of the target scaffolds.
To develop …
Technology For The Organic Chemist: Three Exploratory Modules,
2010
Butler University
Technology For The Organic Chemist: Three Exploratory Modules, John J. Esteb, Luanne M. Mcnulty, John Magers, Paul Morgan
Scholarship and Professional Work - LAS
The ability to use computer-based technology is an essential skill set for students majoring in chemistry. This exercise details the introduction of appropriate uses for this technology in the organic chemistry series. The incorporation of chemically appropriate online resources (module 1), scientific databases (module 2), and the use of a chemical drawing program (module 3) are detailed here.
Structure-Reactivity Relationships Of L-Proline Derived Spirolactams And A-Methyl Prolinamide Organocatalysts In The Asymmetric Michael Addition Reaction Of Aldehydes To Nitroolefins.,
2010
Technological University Dublin
Structure-Reactivity Relationships Of L-Proline Derived Spirolactams And A-Methyl Prolinamide Organocatalysts In The Asymmetric Michael Addition Reaction Of Aldehydes To Nitroolefins., Fintan Kelleher, Sinead Kelly, John Watts, Vickie Mckee
Articles
L-Proline derived spirolactams and a-methyl prolinamides act as organocatalysts for the asymmetric conjugate addition of aldehydes to nitroolefins in excellent yields, with good diastereoselectivity and enantioselectivity. Furthermore, low catalyst loadings (5 mol%) and a low aldehyde molar excess (1.5 molar equivalents) were achieved.
10,12-Dimethylpteridino[6,7-F][1,10]- Phenanthroline-11,13(10h,12h)-Dione– Chloroform (1/1),
2010
Eastern Illinois University
10,12-Dimethylpteridino[6,7-F][1,10]- Phenanthroline-11,13(10h,12h)-Dione– Chloroform (1/1), Waynie Olaprath, Jennifer Rodin, Kraig A. Wheeler, Mark E. Mcguire
Faculty Research and Creative Activity
In the title co-crystal, C18H12N6O2_CHCl3, intramolecular Cl3C—H_ _ _N hydrogen-bonding interactions occur between a single CHCl3 and both N atoms at the 1,10-positions on the phenanthroline portion of the molecule. The interplanar distance between inversion-related molecules is 3.241 (2) A ° .
Transition Metal-Mediated Higher-Order Cycloaddition Reactions: Application To The Total Synthesis Of Complex Natural Products,
2010
Wayne State University
Transition Metal-Mediated Higher-Order Cycloaddition Reactions: Application To The Total Synthesis Of Complex Natural Products, Bilal Abou Aleiwi
Wayne State University Dissertations
ABSTRACT
TRANSITION METAL-MEDIATED HIGHER-ORDER CYCLOADDITION REACTIONS: APPLICATION TO THE TOTAL SYNTHESIS OF COMPLEX NATURAL PRODUCTS
by
BILAL ABOU ALEIWI
October 2010
Advisor: Dr. James H. Rigby
Major: Chemistry (Organic)
Degree: Doctor of Philosophy
Chromium (0)-mediated [6ð + 2ð] and [6ð + 2ð + 2ð] cycloaddition reactions between cyclic trienes and alkynes is reported. The development, investigation and the application of these reactions in the total synthesis of complex ring systems and natural products is described. Two natural products, namely, ∆ 9(12) -Capnellene and Echinopines A and B were targeted.
An investigation led to the successful development of a methodology to …
Development And Applications Of Thioacids In Peptide Chemistry And Exploration Of Methods Toward The Stereochemical Elucidation And Synthesis Of Virgineone,
2010
Wayne State University
Development And Applications Of Thioacids In Peptide Chemistry And Exploration Of Methods Toward The Stereochemical Elucidation And Synthesis Of Virgineone, Kasinath Sana
Wayne State University Dissertations
ABSTRACT
DEVELOPMENT AND APPLICATIONS OF THIOACIDS IN PEPTIDE CHEMISTRY AND EXPLORATION OF METHODS TOWARD THE STEREOCHEMICAL ELUCIDATION AND SYNTHESIS OF VIRGINEONE
by
KASINATH SANA
December 2010
Advisor: David Crich
Major: Chemistry
Degree: Doctor of Philosophy
This dissertation describes investigations toward the development of methods for the synthesis of peptidyl thioacids and thioesters, with particular emphasis on applications in peptide chemistry, and the exploration of methods toward the assignment of the relative and absolute configuration of virgineone and its total synthesis.
The first part of chapter one introduces the general characteristics and reactivity of thioacids, and describes their potential for application …
Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation,
2010
Wayne State University
Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian
Wayne State University Dissertations
This thesis describes investigations directed at the development of methods for the selenosulfide and disulfide rearrangements for the permanent functionalization of thiols, and in particular of cysteine and carbohydrate based thiols. Emphasis is placed on the newly invented silver mediated allylic desulfurative rearrangement for the primary modification of thiols and the synthesis of complex oligosaccharide mimics.
Chapter one introduces the concept of chemoselective ligations for the modification of macromolecules like carbohydrates and proteins. It overviews the native and non-native ligation techniques for their modification of such entities with a attention focusing on thiol based ligation techniques. The later part of …
I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra
Wayne State University Dissertations
Microwave-influenced diversity-oriented synthesis of biologically relevant small and natural-product-like molecules via multicomponent coupling reactions (MCCRs) have been investigated. Cheap, readily available starting materials in conjunction of microwave irradiation and employment of environmentally benign solvent (e.g. water) provided a common platform that allowed to access a wide array of structurally and skeletally diverse molecules. The investigation allowed us to establish a new paradigm of diversity-activity relationships (DARs) by tuning reacting components of the MCCRs and proved that in contrary to the conventional use of microwave as a rate accelerating tool, it can be used to influence reactivity of molecules. The method …
Conversion Of Racemic Ibuprofen To (S)-Ibuprofen,
2010
University of Texas at El Paso
Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, David Chavez-Flores
Open Access Theses & Dissertations
Ibuprofen is a common Non-Steroidal Anti-Inflammatory Drug (NSAID) sold as a racemic or equal mixture of (R) and (S) mirror-image enantiomers. Without patent protection, ibuprofen is an orphan drug even though one enantiomer, (S)-ibuprofen, provides relief three times faster than its racemic mixture with fewer side effects. The goal of this research was to develop a facile, environmentally benign (no waste of ibuprofen or catalysts), and inexpensive process to convert a commercially available racemic mixture of ibuprofen to the therapeutically active (S)-ibuprofen.
After many attempts, the most successful conversion of racemic ibuprofen to (S)-ibuprofen was the in situ racemization and …
Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite.,
2010
Universiti Malaya
Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite., Fadheel A. A. Alsanabani
Student Works (2010-2019)
A slightly branched urethane acrylate macromer (UAM) was synthesized by reacting palm oil-based polyol with excess amounts of polymeric methylene diphenyl diisocyanate (MDI) to form urethane prepolymer, then reacted with 2-hydroxyethyl methacrylate (HEMA) and FT-IR spectroscopy confirmed the urethane and grafted acrylate groups. 0.2% by weight of camphoroquinone (CQ) and 0.8% by weight of ethyl-4-N,N-dimethylamino-benzoate (4EDMAB) by weight were added to render the experimental resins light-curable. Their viscosity, percentage of degree of conversion (%DC) and cross-linking density (CLD), percentage of volumetric polymerization shrinkage (%VPS), water sorption and solubility, flexural strength, modulus of elasticity and toughness were determined and compared to …
Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution,
2010
Colby College
Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein
Honors Theses
It is well known that electron withdrawing groups, such as nitro or carbonyl groups, activate benzene rings for nucleophilic aromatic substitution. However, little research has been done to investigate the electron withdrawing capability of acetylene groups for substitution of aromatic halides. Experimental and computational investigations on the reactivity of halogenated phenylacetylenes with oxygen and other nucleophiles will be described.
Solid Supported Synthesis Of Secondary Amines Via Staudinger And Microwave Aza-Wittig Reactions,
2010
Butler University
Solid Supported Synthesis Of Secondary Amines Via Staudinger And Microwave Aza-Wittig Reactions, Kyle Thomas Holsinger
Undergraduate Honors Thesis Collection
Amine bond formation is a major topic in organic chemistry and is widely applied to the formation of medicinal compounds. Current studies have analyzed the benefits of microwave irradiation and solid supported reagents in order to improve reaction conditions and both synthetic and environmental costs. In the synthesis of amines, we investigate the combined use of microwave irradiation and solid supported reagents in the aza-Wittig and reductive amination reaction.
Synthesis Of Functionalized Gpi Anchors And Related Glycoconjugates,
2010
Wayne State University
Synthesis Of Functionalized Gpi Anchors And Related Glycoconjugates, Benjamin M. Swarts
Wayne State University Dissertations
This dissertation is divided into two chapters describing the background, significance, and synthesis of GPI anchors and GPI-anchored molecules. GPI anchors are a class of complex glycolipids with the primary purpose of attaching cell surface proteins/glycoproteins to the cell membrane. The first chapter is focused on the synthesis of functionalized GPI anchors, and begins with an introductory look at the discovery, structure, biosynthesis, and biological functions of GPIs. Then, after surveying progress and achievements in GPI synthesis, including discussion about current strategic shortcomings in the field that prevent the chemical synthesis of various GPI derivatives, our approach to accessing uniquely …
Synthetic Studies On Angucycline C104,
2010
University at Albany, State University of New York
Synthetic Studies On Angucycline C104, Rui Zheng
Legacy Theses & Dissertations (2009 - 2024)
The Hauser's annulation and Hauser and Xu's route for C-aryl glycoside synthesis were successfully employed to prepare the linear tetracyclic anthraquinone substituted C-aryl glycoside, galtamycin as well as bis C-aryl glycosides. Synthetic studies on angucycline C104 extended the utility of both methods to structures with angular tetracyclic framework.
A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst,
2010
Illinois Wesleyan University
A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram Mohan, Jason Bothwell, Veronica Angeles, James Carolan, Margaret Olson
Scholarship
The most common method for the deprotection ofTBDMS ethers utilizes stoichiometric amounts of tetrabutylammonium fluoride, n-Bu4N+F(TBAF), which is highly corrosive and toxic. We have developed a mild and chemoselective method for the deprotection ofTBDMS, TES, and TIPS ethers using iron(III) tosylate as a catalyst. Phenolic TBDMS ethers, TBDPS ethers and the BOC group are not affected under these conditions. Iron(III) tosylate is an inexpensive, commercially available, and non-corrosive reagent.
Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water,
2010
Illinois Wesleyan University
Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water, Ram Mohan, Margaret Olson, James Carolan, Michael Chiodo, Phillip Lazzara
Scholarship
The deprotection of aromatic as well as conjugated acetals and ketals in water is catalyzed by iron(III) tosylate (1.0–5.0 mol %). Iron(III) tosylate is an inexpensive and readily available catalyst. The use of water, the most environmentally benign solvent, makes this procedure especially attractive for acetal deprotection.
