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Synthesis, structure, and reactivity of group 4 metal-carboryne complexes. / CUHK electronic theses & dissertations collection

A series of group 4 metal-carboryne complexes were synthesized by the reaction of Li2C2B10H10 with dichloro group 4 metal complexes. Reaction of (eta2-C 2B10H10)ZrCl2(THF)3 with 2 equiv of [MeC(NCy)2]Li or [nPr 2NC(NPri)2]Li also effectively yielded the corresponding group-4-metal-carboryne complexes. On the other hand, treatment of C2B10H10)ZrCl2(THF) 3 with 2 equiv of tBuOK or [ tBuCOCHCOtBu]Na gave unexpected product [(eta2-C2B10H10) 2Zr(OtBu)(THF)] [Zr(OBu t)3(THF)3] or [sigma:sigma:sigma-{ tBuC(O)=CHC(tBu)(O)C 2B10H10}]Zr(eta2- tBuCOCHCOBut)(THF)2 . / Finally, the reactivities of aforementioned zirconacyclopentene and zirconacyclopentane complexes were studied. A new class of benzocarboranes and dihydrobenzocarboranes were prepared by indirect [2+2+2] cycloaddition of carboryne with two different alkynes, or with one alkene and one alkyne, mediated by Ni(II) or Fe(III). In the presence of CuCl and HMPA, zirconacyclopentenes or zirconacyclopentanes reacted with ortho-dihalobenzene reagents to generate naphthalocarborane or dihydronaphthalocarborane derivatives. A series of carborane fused cyclobutenes and cyclobutane were also prepared from zirconacyclopentenes or zirconacyclopentanes complexes mediated by Cu(II). / Next, the reactivities of Cp2Zr(mu-Cl)(mu-C2B 10H10)Li(OEt2)2 toward alkynes, alkenes and pyridines were studied. Various kinds of internal alkynes, and terminal alkenes reacted with this Zr-carboryne precursor to effectively generate the mono- insertion products zirconacyclopentene and zirconacyclopentane, respectively. Interaction of Cp2Zr(mu-Cl)(mu-C2B10H 10)Li(OEt2)2 and pyridines afforded a new kind of carboranyl zirconocene complexes via C-H activation at alpha-position of pyridines. / Subsequently, the reactivities of group 4 metal-carbroyne complexes toward unsaturated molecules were studied. Polar molecules such as azide, ketone, nitrile, carbodiimide, isocyanate, thioisocyanate, carbon disulfide, and isonitrile were inserted into the M-C bond in metal-carboryne complexes to form mono-, di-, or tri-insertion products. These metal-carboryne complexes, however, showed no reactivity toward internal alkynes and alkenes. Terminal alkynes protonated the carboryne complexes to afford neutral o-carborane. / Ren, Shikuo. / Adviser: Zuowei Xie. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 250-271). / 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.

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344541
Date January 2010
ContributorsRen, Shikuo., Chinese University of Hong Kong Graduate School. Division of Chemistry.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, theses
Formatelectronic resource, microform, microfiche, 1 online resource (xxiii, 293 leaves : ill.)
RightsUse 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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