Luk To. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 115-123). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgement --- p.ii / Abstract --- p.iii / Abbreviation --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1-1 --- Background --- p.1 / Chapter 1-2 --- Sharpless Epoxidation --- p.2 / Chapter 1-3 --- Mn-Salen Complexes for Epoxidation --- p.4 / Chapter 1-4 --- Oxaziridinium Salts --- p.6 / Chapter 1-5 --- Dioxiranes --- p.9 / Chapter 1-6 --- Asymmetric Epoxidation by Dioxirane --- p.12 / Chapter 2. --- Results and Discussion --- p.31 / Chapter 2-1 --- Epoxidation of trαns-disubstituted and trisubstituted alkenes catalyzed by L-αrαbino-4-uloses --- p.31 / Chapter 2-2 --- Epoxidation of cis-alkenes catalyzed by L-arabino-4-uloses --- p.47 / Chapter 2-3 --- Epoxidation of alkenes catalyzed by new L-arabino-4-uloses --- p.55 / Chapter 3. --- Conclusion --- p.77 / Chapter 4. --- Experimental Section --- p.80 / Chapter 5. --- References --- p.115 / Chapter 6. --- Appendix --- p.124

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 11, 2008) Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 46 p. : ill. Includes abstract. Includes bibliographical references (p. 45-46).

Thesis (Ph.D.) - University of St Andrews, September 2008. / Restricted until 16th September 2009.

No description available.

Heterogeneous enantioselective catalysis strives to create new successful catalysts. One of the most researched examples is the hydrogenation β-ketoesters using nickel-based catalysts. A hindrance in the industrial scale-up of this enantioselective hydrogenation reaction is the lack of exact details of how chirality is bestowed onto this achiral metal surface. While a number of mechanisms have been proposed to explain the enantioselective behaviour of this system, these are predominantly based on catalytic studies. An alternative approach is through surface science studies examining the morphology, structure and composition of this catalytic system. A range of ultrahigh vacuum based model studies investigating the structure and composition of ultrathin Ni films and Ni/Au surface alloys on Au{111} using the techniques of Scanning Tunnelling Microscopy (STM) and Medium Energy Ion Scattering (MEIS) are presented in this thesis. In addition, the adsorption of the chiral modifier (S)-glutamic acid has been studied on these surfaces using vibrational spectroscopy (Reflection Absorption Infrared Spectroscopy (RAIRS)) and Temperature Programmed Desorption (TPD). Furthermore, MEIS has been used to investigate the influence of (S)-glutamic acid on the surface composition of Au/Ni model catalysts detecting effects such as adsorbate induced segregation and de-alloying behaviour. In addition, colloidal preparative routes have been used to synthesise bimetallic Au/Ni nanoparticles supported on mesoporous silica. The catalysts are then modified by the adsorption of the chiral ligand, (R,R)-tartaric acid. Finally, the catalysts are tested for their activity and enantioselectivity with respect to methylacetoacetate hydrogenation. At each stage the catalysts are characterised by a combination of Extended X-ray Absorption Fine Structure (EXAFS); Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDS) and Atomic Absorption Spectroscopy (AAS).

The research presented in this thesis is a project funded by the EU-network of the Marie Curie project NANO-HOST in collaboration with partner institutes. The aims of this network are to develop innovative methods for the preparation, recovery and reuse of single-site, nanostructured catalytic materials, and further on apply them in combination with specifically engineered reactors for a sustainable production process for making high value fine chemicals. One part of this project was to prepare chiral diphosphine ligands and their complexes for currently challenging reactions, such as asymmetric carbonylations (homogeneous catalysis). Catalytic studies of these chiral diphosphine ligands were carried out in asymmetric hydroxy-and alkoxy-carbonylations and hydrogenation reactions. The second part of this project was the heterogenisation of these chiral homogeneous complexes through collaborations with the network partners and furthermore their catalytic behavior was studied.

There is an increasing necessity for the pharmaceutical industry to develop enantiomerically pure drugs. Up till now, production of enantiomerically pure molecules has been provided by harvesting them from plants or utilising homogeneous catalysis and biocatalysis. None of these methods are efficient means of production, and attention is now being directed towards heterogeneous enantioselective catalysis as the preferred technique. This is on account of the high product yield and ease of separation of catalyst from the reaction mixture. Over the past few decades, a great deal of research has been conducted into investigating the Ni catalysed hydrogenation of β-ketoesters and Pt catalysed hydrogenation of α-ketoesters. These are the most successful systems for enantioselective heterogeneous catalysis. However, they are unsuitable for industrial purposes due to the low thermal and mechanical stability of the modified surfaces. The main goal throughout this project has been the investigation of surface-confined covalent reactions. The motivation of this research is to develop enantioselective heterogeneous catalysis; covalent networks are believed to infer the necessary thermal and chemical stability required to chirally modify catalytic surfaces for docking interactions with reactant species. Covalent organic frameworks (COFs) on surfaces hold potential for a number of chemical applications, and not just in the field of heterogeneous catalysis; for example in areas such as molecular electronics and templating.

The development of peptides as catalysts for preparing optically active molecules is an ongoing investigation. Efforts at expanding the use of peptides are explored in two ways: investigating novel reactions in which peptides can act as asymmetric catalysts and through expanding the substrate scope of peptides in performing kinetic resolutions. Attempts at furthering the reaction scope of acylsulfonamide-containing peptides to act as BrØnsted acids through promoting the attack of 7-methyl oct-6-ene-1-tosylaziridine (9) by an internal π-nucleophile are discussed herein. Also reported is the use of pentameric peptides containing a π(-methyl)histidine residue in the kinetic resolution of the primary alcohol 4-hydroxymethyl cyclopent-2-enone (76) and the secondary aliphatic alcohol 2- pentanol. Moderate selectivities were observed in the kinetic resolution of 4-hydroxymethyl cyclopent-2-enone (76) and promising results were obtained in the initial screening of catalysts for the resolution of 2-pentanol. / Thesis (MS) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis (Ph. D.)--University of Chicago, Department of Chemistry, August 2002. / Includes bibliographical references. Also available on the Internet.