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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.

The Development of Amino Acid-Derived Catalysts for the Enantioselective Silylation of Alcohols: An Application to the Total Synthesis of Sapinofuranone A

Rodrigo, Jason January 2010 (has links)
Thesis advisor: Marc L. Snapper / Chapter 1. Review of efficient, non-enzymatic methods for the catalytic enantioselective functionalizations of alcohols Chapter 2. Introduction of the first catalytic asymmetric silylation of of alcohols for the desymmetrization of meso-diols Chapter 3. Presentation of enantioselective catalytic silylation for the regiodivergent reaction on a racemic mixture. Application of this method to the first enantioselective synthesis of sapinofuranone A. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

The development and evaluation of an individualized learning programme for the teaching of organic chemistry at form six level.

Hung Ip, Kit-lin, Margaret. January 1977 (has links)
Thesis--M. Phil., University of Hong Kong, 1978. / Copy 2 xerox copy of typescript. Typescript.

Biorecycling of waste in Hong Kong /

Chan, Lap-shun. January 1986 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1987.

Total syntheses of (±)- cylindricines A, D, and E, and (±)- deoxypenostatin A : synthetic approaches toward the synthesis of (±)- penostatins A and B /

Liu, Tao. January 2000 (has links)
Thesis (Ph. D.)--Brandeis University, 2000. / "UMI:9967594." MICROFILM COPY ALSO AVAILABLE IN THE UNIVERSITY ARCHIVES. Includes bibliographical references.

The structure of bromonium, chloronium, and oxonium ions

Schubert, Jeffrey W. January 2008 (has links)
Thesis (M.S.)--Villanova University, 2008. / Chemistry Dept. Includes bibliographical references.

Studies towards the asymmetric total synthesis of oximidines I and II

Oppenheimer, Jossian, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvii, 185 p.; also includes graphics Includes bibliographical references (p. 176-185). Available online via OhioLINK's ETD Center

Electroorganic synthesis inter- and intra-molecular anion radical cycloadditions, and electrogenerated base promoted coupling reactions /

Felton, Greg Andrew Nicholas, Bauld, Nathan L. January 2005 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Nathan L. Bauld. Vita. Includes bibliographical references.

Origins of the structural theory in organic chemistry

Rocke, Alan J., January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Synthesis and reactivity of organotantalum complexes containing nitrogen ligation

Fox, Peter Anthony, 1965- January 1996 (has links)
This work examines various aspects of hydrodenitrogenation catalysis. Various tetrahydroquinolinyl (THQ) and indolinyl (DHI) complexes of tantalum were synthesized including: Ta(THQ)ₓCl₅₋ₓ(x = 1 to 5), Ta(DHI) ₓCl₅₋ₓ(THF) (x = 1 and 2). In addition, THQ and DHI complexes containing aryloxide (OAr = 2,6-diisopropylphenoxide) and alkyl complexes were also synthesized: Ta(THQ)(OAr)Cl₃(OEt₂), Ta(THQ)₂(OAr)₂Cl, Ta(THQ)(OAr)R₃Cl (R = Me and Et), Ta(THQ)₂(OAr)₂R (R = Me and Et), Ta(DHI)(OAr)Cl₃(OEt₂), and Ta(DHI)₂(OAr)₂Cl. The effects of sulfur ligation versus oxygen ligation was examined by comparison of the crystal structures of Ta[η²(N,C)-2,4,6-tri-t-butylpyridinel](OAr)₂(OᵗBu) and Ta[η²(N,C)-2,4,6-tri-t-butylpyridine](OAr)₂(SᵗBu). The sulfur ligand donates less π density to the metal center, resulting in a longer Ta-C bond for the pyridine ligand. The arene complexes (η⁶C₆Me₆)Ta(OAr)(SAr')Cl and (η⁶-C₆Me₆)Ta(OAr)(SAr'')Cl were also synthesized. These arene-thiolate complexes do not appear to bind quinoline, unlike the oxygen analogs A number of Ta(η⁴-diene)(OAr)₃ complexes were synthesized (diene = butadiene, isoprene, 2,3-dimethylbutadiene, 1,3-cyclohexadiene) and their reactivity with respect to nitriles examined. Nitriles typically insert into Ta(η⁴-isoprene)(OAr)₃ to form (ArO₃Ta(CH₂CHCMeCH₂CRN) which can then be thermally rearranged to (ArO) ₃Ta(=NCRCH₂CHCMeCH₂) (R = Me, Ph, ᵗBu). Similar reactivity is observed with butadiene and 2,3-dimethylbutadiene diene complexes. The Ta(η⁴-C₄H₆)(OAr)₃ complex is also capable of inserting two nitriles to form (ArO)₃Ta(NCRCH₂CHCHCH₂CRN), whereas Ta(η⁴-1,3-cyclohexadiene)(OAr)₃ only forms the bis-insertion product. Aspects of the formation of the above complexes with specific concentration on the tantalum-nitrogen interactions are presented.

Chemical studies of necic acid analogues

Guthrie-Strachan, Jeffry James January 1997 (has links)
Various aldehydes have been reacted with methyl acrylate under Baylis-Hillman conditions, using DABCO as a catalyst, to afford a range of α-substituted acrylic esters containing an allylic hydroxy group. Selected Baylis-Hillman products have been brominated, hydrolysed and acetylated to afford substrates for the synthesis of necic acid analogues. The diastereo- and regioselectivity of nucleophilic attack, using sodium methylmercaptan, on the Baylis-Hillman products and selected brominated derivatives was investigated. The allylic hydroxy compounds favour conjugate addition with the generation of a new chiral centre, while the allylic bromo derivatives favour substitution (SN and SN') (S[subscript N] and S[subscript N]') with consequent loss of chirality. (E)-2-Isopropylcrotonic acid, a vital precursor in the synthesis of all stereoisomers of trachelanthic and viridifloric acid, was synthesised in an attempt to obtain the necic acid components required for total alkaloid synthesis of lycopsamine and its derivatives. This precursor and salicylic acid were then used to prepare esters of retronecine, a dihydroxy necine base obtained via extraction and consequent hydrolysis of retrorsine.

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