beta-Hydroxylethyl rhodium porphyrins underwent selective carbon-carbon bond activation with ether at the Calpha-Cbeta position to give alkyl (Cbeta) rhodium porphyrins under mild conditions. Enhanced rates and yields were observed for electron-poor and non-planar rhodium porphyrins. The beta-hydroxylethyl rhodium porphyrins are proposed to undergo beta-hydroxyl elimination to yield cationic rhodium porphyrins which behave as Lewis acids and selective activation of Calpha-Cbeta carbon carbon bond is likely assisted by hydroxide. / beta-Substituted alkyl iridium porphyrins reacted with TEMPO via beta-hydrogen atom abstraction. The beta-aryl substituted radicals, stabilized by resonance, reacted with TEMPO and transformation subsequently occurred to give (ttp)IrCH 2COAr in high yield. For beta-non-aryl substituted radicals, fragmentation proceeded to give (ttp)IrII metal-centered radicals which then reacted with TEMPO via aliphatic carbon-carbon bond activation to give (ttp)IrMe. / Reversible 1,2-rearrangements of beta-nitrogen substituted alkyl metalloporphyrins proceeding via beta-hydride elimination and beta-amino elimination pathways have been observed. The rates and equilibrium positions were found to be dependent on the electronic nature of the beta-substituent. The mechanism of the 1,2-rearrangements is consistent with the beta-hydride elimination/metal-hydride olefin re-insertion mechanism. Competitive beta-amino elimination was identified in electron rich amino substituents. / The objectives of this research focus on studies of unusual reactivities of d6 cobalt, rhodium and iridium alkyl porphyrin complexes including beta-hydride elimination, beta-hydrogen atom abstraction and beta-hydroxyl elimination reactions. / Yeung Siu Kwan. / "December 2005." / Adviser: Kin Shing Chan. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6400. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_343729 |
| Date | January 2005 |
| Contributors | Yeung, Siu Kwan., Chinese University of Hong Kong Graduate School. Division of Chemistry. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xi, 268 p. : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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