rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: N-heterocyclic carbene catalysis
    sub title: expansion of substrate scope and synthesis of electronically diverse tetraaryl N-heterocyclic imidazolium carbene ligands
  name:
    name part: Ogle, James William.
    role:
      role term: creator
  name:
    name part: Miller, Stephen A.
    role:
      role term: thesis advisor.
  name:
    name part: Burgess, Kevin
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2010
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: electronic
    form: remote
    extent: 1 online resource.
  abstract: Asymmetric hydrogenation as a general route to polypropionates has been explored for allylic alcohols, acids, and derivatives, which has led to the generation of 2,4-dimethylated hexane derivatives. Quantitative yields in most cases and enantioselectivities greater than 98% were obtained. A remarkable stereofacial inversion was observed when an ester or acid was present in the allylic position instead of an alcohol or alcohol derivative. This led to the construction of all four diastereomers of the hexanol series from a single enantiomer of hydrogenation catalyst. Also described are an attempted synthesis of (-)-lardolure, a formal synthesis of the methyl ester portion of the preen gland extract from the domestic goose Anser anser, and a total synthesis of an extract from the fungi A. cruciatus. The synthesis of these compounds demonstrated shortcomings of the known catalyst system showing enantioselectivities for polymethylated compounds was high, while diastereoselectivity was low. Methodology to develop new N-heterocyclic carbene catalysts was developed using the cyanide coupling of aldimines to generate electronically tunable 1,3,4,5-tetraaryl complexes, and X-ray, IR, and calculations were used to elucidate their electronic characteristics. These studies indicate that the 4,5-positions have as great an influence on the metal-ligand bond as the 1,3-positions. In addition, they are among the most electron-donating 2- metalated N-heterocyclic carbenes found thus far. An intrinsic relationship between catalytic activity and electron donating ability was found in transfer hydrogenations.
  note: by James William Ogle.
  note: "Major Subject: Chemistry"
  note: Title from author supplied metadata (automated record created 2010-03-12 12:08:51).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2008 http://hdl.handle.net/1969.1/ETD-TAMU-3126
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major chemistry
  subject:
    topic: imidazolium
  subject:
    topic: electronic
  subject:
    topic: carbenes
  subject:
    topic: hydrogenation
  subject:
    topic: catalysis
  subject:
    topic: asymmetric
  subject:
    topic: iridium
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-3126
  record info:
    record content source: TXA
    record creation date: 100427
    record change date: 20151201120129.0
    record identifier: in00002589201