*Please refer to dissertation for diagrams. / Part 1 describes the selective C(alpha)-(beta) bonds cleavage of a series of aliphatic ethers (RCH2OCH2R: R = Et, Pr, Bu, iBu and pentyl) by RhII(tmp) using PPh3 as the promoting ligand to give Rh(tmp)-alkyls bearing the C(beta)-substituent in 13-40% yields at 24°C. The rate and the yields of Rh(tmp)-alkyls decreased with increasing steric hindrance of ethers. Addition of bases such as KOtBu, CsOH.H2O and KOH as well as H2O further promoted the product yields of the reactions with n-butyl ether to 56-62%. The reaction between RhII(tmp) and the cyclic ether, oxepane, at 24°C for 1 day gave Rh(tmp)(CH2)5OCHO in 17% yield suggesting that Rh(tmp)OH is the key intermediate in the C-C cleavage step and presumably generated via the PPh3-, H2O-, and OH --assisted disproportionation of RhII(tmp).* / Secondly, the reductive dehydrogenation of Rh(tmp)H to RhII(tmp) was also observed. Rh(tmp)H reacted with KOH in benzene-d6 at 100°C for 1 hour to give RhII(tmp) in 30% yield. [Rh I(tmp)]- is proposed to form initially via the deprotonation of Rh(tmp)H with KOH and then reacts with the unreacted Rh(tmp)H to give Rh II(tmp) via electron transfer. Thirdly, the hydroxide-induced disproportionation of RhII(tmp) to RhIII(tmp)OH and [Rh I(tmp)]- has also been proposed.* / The objective of this thesis focuses on studies of selective, base-promoted aliphatic carbon(alpha)-carbon(beta) bond activation (CCA) of ethers with rhodium(II) and rhodium(III) meso-tetramesitylporphyrin complexes (Rh II(tmp) and Rh(tmp)I). The roles of potassium hydroxide in promoting the interconversions of rhodium porphyrin species (RhII(tmp), Rh(tmp)I, Rh(tmp)OH and Rh(tmp)H) will also be discussed. / Lai, Tsz Ho. / Adviser: Kin Shing Chan. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 161-172). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344540 |
| Date | January 2010 |
| Contributors | Lai, Tsz Ho., 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 (xii, 196 leaves : 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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