The potential of chalcogen containing reagents in organic synthesis was investigated. More specifically, the efficiency of bis(triphenylstannyl) selenide (105) and telluride (95) in the reductive dehalogenation of alpha-halocarbonyl compounds was illustrated. The mechanism of the dehalogenation process was also examined. The intermediacy of a transitional enolate species was established by the successful isolation of the chalcone condensation product, resulting from reaction with benzaldehyde. A difference in the reactivity of bis(triphenylstannyl) selenide (105) and bis(tert-butyldimethylsilyl) telluride (95) in the dehalogenation process was discerned. / An investigation directed at the elaboration of a system capable of generating a diatomic selenium unit was carried out. The thermal decomposition of titanocene pentaselenide (177), in the presence of diene trap 2,3-diphenyl-1,3-butadiene (153), was demonstrated to generate the monoselenide adduct 2,5-dihydro-2,3-diphenylselenophene (207). In the process, 1H NMR evidence was obtained for the formation of diselenide 180, indicative of the generation of a diatomic selenium species. Extensive refluxing of a reaction mixture composed of titanocene pentaselenide (177) and 2,3-diphenyl-1,3-butadiene (153) was shown to ultimately result in the formation of 3,4-diphenylselenophene (181). Mechanisms were proposed to account for these processes.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36704 |
| Date | January 1999 |
| Creators | Schultz, Erwin. |
| Contributors | Harpp, David N. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001747718, proquestno: NQ64663, Theses scanned by UMI/ProQuest. |
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