A methodology for the catalytic asymmetric hydroboration of vinylarenes with pinacolborane has been developed. Use of pinacolborane in hydroboration, especially catalytic asymmetric hydroboration grants direct access to chiral boronate esters, without the cryogenic temperatures required for catalytic hydroboration with catecholborane and the subsequent transesterification with excess pinacol. These chiral boronate esters were then subjected to a homologation/oxidation sequence previously refined in our labs to prepare Naproxen™ in 66% yield and 88% enantiopurity from its corresponding vinyl arene precursor. A survey of metal catalysts, solvents and ligands revealed remarkable changes in regioselectivity with changes in metal. Rhodium catalysts in combination with pinacolborane were able to provide regioselectivity for the secondary branched isomer equivalent to those obtained with catecholborane. Iridium catalysts showed a near perfect regioselectivity for the primary linear isomer. With respect to the choice of chiral ligand, complete reversal in the enantiomer obtained was observed with the choice of hydroborating reagent from catecholborane to pinacolborane. In order to understand the regioselectivity observed under iridium catalysis, deuterium labeling studies were undertaken. A synthesis of the deuterated hydroboration reagent pinacolborane was first completed. From the results of these studies, in combination with published thermodynamic data, a mechanism for the iridium catalyzed hydroboration of alkenes was proposed. / Thesis (Ph.D, Chemistry) -- Queen's University, 2007-08-29 09:30:38.571

Recent high-pressure experiments on iridium show a transition to a 14 atomic layer superlattice structure. Since iridium has a high bulk modulus, it is used in many high-pressure applications, for instance as a gasket for high-temperature, high-pressure diamond anvil cell experiments. The effects of pressure on this material are hence of interest. Of the transition metals, the iridium surface has been one of the most extensively studied surfaces experimentally. The field ion microscope has made it possible to observe in detail the behaviour of adatoms on the surface, and has led to interesting discoveries of the nature of atomic adsorption on the lr(111) surface. A number of theoretical and semi-empirical studies have been made on this topic. However, none of these studies take atomic relaxations into account in a satisfactory manner, and therefore do not give a complete understanding of the process of incorporation of adatoms onto the surface. In the present work, first-principles total energy calculations based on the plane wave pseudopotential method within the framework of the density functional theory are employed in the study of the bulk properties of iridium, and the crystal phases and defect structures of iridium under pressure. The bond-orientation model is extended to include the effects of pressure, and used to compute all of the ~2n defect structures of iridium as a function of atomic volume. Allowance for full atomic relaxations is made in computing the ideal and relaxed surface formation energies of the three low-index surfaces of iridium, and in investigating the nature of adsorption of single adatoms on the lr(111) surface. The formation energy of a vacancy on the Ir(111) surface is also computed. This is the first time such a calculation has been made. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.

Thesis (Ph.D.)--McMaster University (Canada), 1993. / Source: Dissertation Abstracts International, Volume: 54-12, Section: B, page: 6257. Adviser: D. G. Burke.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 118-124). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 72-75).

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [283]-292).

Thesis (Ph. D.)--University of Texas at Austin, 2009. / Title from PDF title page (University of Texas Digital Repository, viewed on Aug. 6, 2009). Vita. Includes bibliographical references.

Techn. University, Diss., 2005--München.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references. Also available in electronic version.

Marburg, Univ., Diss., 2004. / Erscheinungsjahr an der Haupttitelstelle: 2003