Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Chemistry." Includes bibliographical references.

No description available.

No abstract available. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

Submitted in fulfillment of the requirements for the award of the Degree of Master of Applied Science in Chemistry, Durban University of Technology, Durban, South Africa, 2016. / The 𝛼-aminophosphonates (APs) and dihydropyrimidinones (DHPMs) exhibit a wide range of important biological activities. The great potential of these compounds in biological applications prompted an increased interest in the development of efficient synthetic methods for their preparation. A novel rhodium supported boron nitride (RhBNT) material was synthesized by simply mixing boron nitride in a solution of rhodium acetate, under inert atmosphere for 7 days followed by filtration; the yield was 95 %. It exhibited excellent catalytic properties for the synthesis of 13 novel APs and 5 DHPMs. Characterization of RhBNT was performed by several techniques: the crystalline nature of RhBNT and nano size was confirmed by SEM spectroscopy, EDX pattern for RhBNT showed signals for rhodium metal, the Brumnauer-Emmett-Teller (BET) analysis showed the specific surface area of RhBNT to be 28.12 m2/g, pore volume 0.23cm3/g and pore size of 199.8Aº thereby suggesting RhBNT as a potentially effective catalyst for organic reactions; the mesoporous nature of the material was established by a type- IV adsorption isotherm; the DSC-TGA Profile indicates that RhBNT has good thermal stability and can be used adequately for catalysis. The DSC curve showed evidence of a broad exothermic peak. The RhBNT was subsequently used in the Kabachnik-Fields and Biginelli reaction in order to assess its catalytic potential. Herein Vilsmeier-Haack reagent was used to synthesize 4-oxo-chromene-3-carbaldehyde and 4-oxo-4H-benzo[h]chromene-3- carbaldehyde from 2-hydroxyacetophenone and 1-hydroxy-2-acetonaphthone, respectively. These two carbaldehydes were subsequently used to synthesize thirteen novels APs and five DHMPs using RhBNT as the catalyst The antimicrobial activities of the synthesized compounds were assessed against Escherichia coli, Bacillus cereus, Micrococcus luteus, Staphylococcus aureus and Candida albicans using the disc diffusion method. It was found that none of the compounds inhibited growth of bacteria or fungus. The assessment of toxicity was evaluated by using the brine shrimp lethal test. It was found that six of the novel compounds exhibited more than 50% brine shrimp death and were considered toxic against Artemia sp. and hence unsuitable as a potential drug whilst four compounds were found to be less toxic, exhibiting a brine shrimp death of less than 50%. Molecular docking studies were carried out for 13 APs to estimate their binding interactions with HIV-1 reverse transcriptase. Four APs showed good potential for the inhibition of HIV-1 reverse transcriptase. / M

Chan Kin Fai. / "April 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 151-157). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

"July 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Thesis advisor: Amir H. Hoveyda / Chapter One Development of Simple Organic Molecules as Catalysts for Enantioselective Allyl Additions to N-Phosphinoylaldimines and Isatins A new catalytic protocol for the enantioselective addition of organoborates to imines and carbonyls is described. This novel method, which does not require transition metals utilizes a modular and easily accessed aminophenol to dictate the stereochemistry of the products. Allyl-additions to N-phosphinoylaldimines and isatins, as well as allenyl-additions to isatins are studied and literature relevant to these transformations is discussed. Additionally, two separate methods for obtaining "crotyl-type" addition products to aldimines; one requiring α-chiral allylboronates and the other requiring a zinc-alkoxide, are discussed. Studies to elucidate the mechanism of this catalytic protocol are also contained in this chapter. Chapter Two Enantioselective Additions to Fluorinated Ketones: A Platform for Studying the Interaction Between Organofluorine and a Small Molecule Utilizing the new protocol discussed in Chapter One, allyl- and allenyl-groups are added enantioselectively to ketones containing a fluorinated substituent. Myriad tertiary alcohols are synthesized, demonstrating the value of this method. This study also allows for examining how organofluorine containing compounds bind to other organic molecules, which is a current topic of intense interest in the field of medicinal chemistry. Mechanistic studies support the idea that, in many cases, the fluorine of the substrate is electrostatically attracted to the ammonium-ion in the catalyst. Chapter Three Enantioselective Additions of Organoboronates to Ketones and Alphaketoesters Promoted by an Aminophenol Containing Catalyst Modification of the aminophenol disclosed in Chapter One allows for increased enantioselectivity for the allyl-addition to both simple ketones (such as acetophenone) and alphaketoesters. For simple ketones, a critical component of the optimal catalyst is replacing the tert-butyl group ortho to the phenol with the sterically large triphenylsilyl group. For alphaketoesters, this tert-butyl group was replaced with the sterically smaller metyl group. Rationale for why these contradictory changes in the catalyst structure lead to higher enantioselectivity for reactions with these two classes of ketones is discussed. Chapter Four Ag-Catalyzed Enantioselective Vinylogous Mannich Reactions of γ-Substituted Siloxyfurans with Aldimines A previously disclosed Ag-catalyzed enantioselective vinylogous Mannich reaction (EVM) with α-, β-, and unsubstituted siloxyfurans is extended to include γ-substituted siloxyfurans. This method, which generates a tertiary stereogenic center concurrent with an adjacent to a quaternary stereogenic center, requires a rarely used 2-thiomethylaniline N-protecting group for the aldimines. / Thesis (PhD) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Bibliography: leaves 134-148.

A range of N-H alkynylaziridines were prepared from amphoteric unprotected aziridine aldehydes without protecting-group manipulation. Unprotected alpha -amino allenes can be obtained from these strained propargyl amines via a 9-BBN mediated hydride transfer. Further transformation of alpha -amino allenes to 2,4,6-trisubstituted pyridines was realized. We also developed another class of amphoteric molecules – alpha-boryl aldehydes, equipped with the tetrahedral MIDA boryl group. A wide range of boryl-substituted building blocks or functionalized boronic acid derivatives have been accessed from these bench-stable alpha-borylcarbonyl compounds. Further chemoselective transformations of these alpha-boryl aldehyde derived building blocks have been conducted, where alph-boryl isocyanates, alpha-aminoboronic acids, acylboronates, and borylated heterocycles were achieved through the decarboxylative functionalization of alpha-borylcarboxylic acids.

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2002. / Vita. Includes bibliographical references (leaves 124-134).