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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.
71

Studies of extended cyanines and related mixed valence compounds

Zhao, Xiaodong 05 1900 (has links)
No description available.
72

Design, synthesis and evaluation of novel inhibitors of cysteine proteases, metalloproteases and the proteasome, a unique high molecular weight proteolytic enzyme

Dotse, Anthony Kwabla 08 1900 (has links)
No description available.
73

Preparation and characterization of thioaurite cluster compounds

Schaaff, T. Gregory 08 1900 (has links)
No description available.
74

Monophosphines in asymmetric catalysis

Laing, John Christopher Pettigrew January 1995 (has links)
This thesis described investigations into the synthesis and reactions of chiral monophosphines, in five chapters. Chapter 1 introduces asymmetric catalysis, Chapter 2 and 3 describe the synthesis of enantiomerically pure monophosphine via an oxide and borane route respectively. Chapter 4 describes the organometallic reactions of these monophosphines and Chapter 5 contains experimental details of the reactions. <strong>Chapter 1</strong> describes the importance of chirality and significant asymmetric processes. The literature methods of producing homochiral monophosphines are detailed. <strong>Chapter 2</strong> describes the synthesis of enantiomerically enriched monophosphine oxides. Diastereomerically pure (2R, 4S, 5R)-2-chloro-5-phenyl-3,4-dimethyl-1,3,2-oxazaphospholidine was prepared from PCl<sub>3</sub> and (-)-ephedrine. This compound was reacted with 2-adamantyl magnesium bromide to afford (2R, 4S, 5R) and (2S, 4S, 5R)-3,4-dimethyl-2-2-adamantyl-5-phenyl-1,3,2-oxazaphospholidin-2-oxide after oxidation with <sup>t</sup>BuOOH. An X-ray crystal structure was obtained of the R<sub>P</sub> diastereoisomer and a detailed NMR study carried out on the S<sub>P</sub> diastereoisomer. The R<sub>P</sub> diastereoisomer was reacted with 2-methoxyphenylmagnesium bromide to give R<sub>P</sub>-N-methyl-N-(1S,2S)-(1-methyl-2-hydroxy-2-phenyl)-ethyl-P-(2-methoxyphenyl)-P-(2-adamantyl)phosphinamide in 68% yield and 95% d.e. The ephedrinyl residue was replaced by O-methyl under acid catalysis with inversion of configuration and with >85% e.e. Displacement of the methoxy group using phenyl lithium occurred with inversion of configuration to give the corresponding phosphine oxide in 65% e.e., which could be reduced under forcing conditions using polymethylhydrosiloxane in the presence of Ti(O<sup>i</sup>Pr)<sub>4</sub>. <strong>Chapter 3</strong> describes the synthesis of enantiomerically enriched monophosphines via phosphine borane complexes. Diastereomerically pure (2R, 4S, 5R)-2,5-diphenyl-3,4-dimethyl-1,3,2-oxazaphospholidine borane was prepared directly from PhPCl<sub>2</sub> and (-)-ephedrine, followed by oxidation with BH<sub>3</sub>.Me<sub>2</sub>S. This compound reacted regiospecifically with ortho-anisyl lithium to afford the product formed by P-O cleavage with >96% d.e. and with retention of configuration at phosphorus. The ephedrinyl residue was replaced by O-methyl under acid conditions with inversion of configuration and with >98% e.e. Ferrocenyl, 1-adamantyl and tert-butyl lithium reagents displaced the methoxy group with inversion of configuration and with >92% e.e., as determined by <sup>1</sup>H NMR methods. The phosphine borane complexes were then reduced quantitatively with Et<sub>2</sub>NH with retention of configuration and with >98% e.e. <strong>Chapter 4</strong> describes the synthesis of indium and rhodium complexes of (S)-t-butyl-(2-methoxyphenyl)-phenyl phosphine and (S)-ferrocenyl-(2-methoxyphenyl)-phenyl phosphine. The iridium complexes are shown to reduce a range of prochiral olefins, including Z-methyl-2-acetylamino-3-phenylpropenoate (MAC) in up to 19% e.e. The di-(R,R)-(ferrocenyl-(2-methoxyphenyl)-phenyl phosphine) rhodium complex is more selective, reducing MAC in 54% e.e., while the rhodium complex of (S)-t-butyl-(2-methoxyphenyl)-phenyl phosphine reduces MAC in 24% e.e.
75

Approaches to the asymmetric synthesis of non-steroidal anti-inflammatory drugs / by Robert Christian Griesbach.

Griesbach, Robert Christian January 1996 (has links)
Bibliography: leaves 159-164. / iv, 158 leaves ; 30cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis examines routes for the asymmetric synthesis of three members of the nonsteroidal anti-inflammatory class of drugs (NSAIDs) The aryl propanoic acid ibuprofen is synthesized in 96% e.e. Control of stereochemistry is achieved by use of the Sharpless epoxidation reaction, followed by reduction of the product epoxide by complex hydride with assistance by titanium tetraisopropoxide acting as a Lewis acid. The final step is the coupling of an optically active carboxylic acid intermediate with the iso-butyl side chain to give (S)-ibuprofen. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1997?
76

Asymmetric [alpha]-amino acid synthesis / by Pasquale Razzino.

Razzino, Pasquale January 1991 (has links)
Bibliography : leaves 198-204. / vi, 204 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1992
77

Asymmetric synthesis with vapol derivatives and novel chiral thiourea organocatalysts

Rampalakos, Konstantinos. January 2008 (has links)
Thesis (Ph.D.)--Michigan State University. Dept. of Chemistry, 2008. / Title from PDF t.p. (viewed on Mar. 27, 2009) Includes bibliographical references (p. 214-219). Also issued in print.
78

Rational design, synthesis and study of novel [alpha]-hetero analogues of ACPA : towards sub-type selective ligands for glutamate-binding proteins /

Nelson, Jared K. January 1900 (has links)
Thesis (Ph. D.)--University of Idaho, 2005. / Abstract. "August 23, 2005." Includes bibliographical references. Also available online in PDF format.
79

Enones and enals as latent enolates in catalytic C-C bond forming processes total synthesis of (-)-paroxetine (Paxil®) /

Koech, Phillip Kimaiyo, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
80

Synthesis, resolution, and diastereoselectivity of the chiral auxiliary trans-2-(9H-flouren-9-yl)cyclohexanol

Cheney, Matthew A. January 2007 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

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