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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Studies in asymmetric synthesis : attempted asymmetric Reformantsky reactions and approaches towards the alkaloid fastigiatine

Armitage, Mark Alan January 1993 (has links)
No description available.
2

The use of In(OTf)3 as a Lewis Acid in carbohydrate chemistry, and exploration in silicon tethered reactions

Bizier, Nicholas Paul. January 2008 (has links) (PDF)
Thesis (Ph. D.)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Mary J. Cloninger. Includes bibliographical references.
3

Some uses of acyliminium ions in the synthesis of isoquinolones with potential biological activity

Taha, Mutasem O. January 1998 (has links)
The preparation of a number of 2-substituted homophthalimides through the condensation of homophthalic anhydride with different arylalkyl arnines is reported. The prepared compounds were alkylated at the 4-position to generate 4-mono-, 4,4-disubstituted and 4-spirocyclic homphthalimides, the analogues of which were reported to have interesting biological activity. Regioselective reduction of the 4-substituted derivatives generated the corresponding carbinolamides. Treating the carbinolamides with mineral or Lewis acids generated N-acyliminiurn ions, which were trapped in situ by one of the following: ( 1) aromatic neucleophiles to generate analogues of the natural product berberine, (2) alkyl chain migration to generate tetrahydrophenanthridones and functionalised isoquinolones, (3) cyclopropane ring-opening to generate 4-alkylisoquinolones, (4) addition to double bond to generate cyclopentaisoquinolones and (5) benzyl or allyl elimination. The oxidation of 4-monosubstituted homophthalimides with triplet dioxygen in alkaline media was investigated, and it generated 4-hydroxyhomophthalimides and isobenzofurancarboxamides. Treating isobenzofurancarboxamides with POCI3 provided a concise route to analogues of the neuroactive naturally-occurring phthalideisoquinolines.
4

Synthesis and material properties of supramolecules containing fluorinated organomercurials

Taylor, Thomas Jackson 15 May 2009 (has links)
This dissertation details the synthesis and analysis of novel supramolecular species that feature simple fluorinated organomercurials, such as trimeric perfluoroortho- phenylene mercury ([o-C6F4Hg]3). These organomercurials can complex a variety of unsaturated substrates including arenes and alkynes. The major emphasis was on developing molecular architectures that are held together in part by secondary Hg-Calkyne interactions. Diphenylpolyynes, hydrocarbons featuring extended regions of unsaturation, were found to complex with [o-C6F4Hg]3 in a series of adducts. While the internal structures of the hydrocarbons themselves were found to be basically unaltered, within the crystals the polyynes were physically separated from one another by intervening molecules of [o-C6F4Hg]3, preventing them from cross-linking. This leads to a substantial stabilizing effect, for example [o-C6F4Hg]3 and Ph(CC)4Ph form a 2:1 adduct that is stable at temperatures up to 120 ºC above the pure hydrocarbon. Adducts of [o-C6F4Hg]3 and molecules containing a 1,3,5-triethynyl benzene core display a variety of novel properties. 1,3,5-tris(trimethylsilylethynyl) benzene forms binary supramolecular stacks with [o-C6F4Hg]3. The structure also displays large cylindrical 1-dimensional cavities. These cavities are lined with non-polar groups, have an internal diameter of 6.2 Å, and remain stable in the absence of guests. The compound readily interacts with and reversibly adsorbs simple alkanes. 1,3,5-tris(phenylethynyl) benzene forms similar stacks with [o-C6F4Hg]3, albeit without the cavities. Upon irradiation with visible and ultraviolet light, this adduct emits a long-lived emission that was hitherto unreported. From computer calculations and lifetime measurements, it appears this radiation is the phosphorescence of the pure hydrocarbon. Intensive structural studies have also been performed on adducts containing polyaromatic compounds, including phenanthrene, and the organomercurials [o- C6F4Hg]3, pentafluorophenyl mercury chloride and bromide. These experiments were performed to determine if Lewis acid-p complexes could be made with monofunctional mercury compounds. Polyaromatic hydrocarbons, such as phenanthrene and diphenylacetylene, were used as the substrates for these investigations. While all the mercurials formed adducts with the substrates, the photophysical measurements were not uniform and indicate that [o-C6F4Hg]3 has a stronger heavy-atom effect because of the cooperativity of the three mercury atoms.
5

Design and evaluation of a new Lewis acid-assisted Lewis acid catalyst system and further applications of a double-allylation reagent

Sivasubramaniam, Umakanthan Unknown Date
No description available.
6

Design and evaluation of a new Lewis acid-assisted Lewis acid catalyst system and further applications of a double-allylation reagent

Sivasubramaniam, Umakanthan. January 2009 (has links)
Thesis (M. Sc.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Oct. 19, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Chemistry, University of Alberta." Includes bibliographical references.
7

Lewis acid-catalyzed atom transfer radical cyclization reactions

晏意隆, Yan, Yi-long. January 2003 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
8

Lewis acid-catalyzed asymmetric atom and group transfer radical cyclization reactions

Zheng, Baofu., 鄭保富. January 2005 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
9

Novel Lewis Acid-promoted cyclization reactions and synthesis of triptolide analogs

Gao, Qiang, 高強 January 2003 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
10

Towards an asymmetric ene reaction

Braddock, D. C. January 1995 (has links)
No description available.

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