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Liquid Phase Hydrogenation of Difficult MoleculesDelargy, L. January 2010 (has links)
No description available.
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292 |
An ab-initio study of Electron Transfer in Ultrcold Molecular Species : The Harpoon MechanismWright, K. W. A. January 2010 (has links)
No description available.
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293 |
Ultrafast Excited State Reaction Dynamics in Aqueous Nanodroplets and Fluorescent ProteinsKondo, Minako January 2010 (has links)
No description available.
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294 |
Development of in-situ synchrotron X-ray powder diffraction techniques for studies of catalytic systemsStrusevich, Dmitry January 2007 (has links)
No description available.
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295 |
Synthesis of New Metal Catalysts for Reactions with a-Olefins and Cyclic EstersBroomfield, Lewis Marc January 2009 (has links)
No description available.
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296 |
Continuous flow reactions at high pressureScovell, Katherine A. January 2008 (has links)
No description available.
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297 |
Investigation of New Organocatalysts Based on Chiral Biaryl AzepinesCormack, Maria January 2010 (has links)
No description available.
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298 |
Time-resolved infrared spectroscopic studies of reaction intermediatesCalladine, James Andrew January 2010 (has links)
No description available.
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299 |
Synthesis of prenylated natural products utilising pericyclic processesLucas, Catherine Louise January 2011 (has links)
This Thesis describes the synthesis of prenylated phenolic natural products using pericyclic reactions, including the aromatic Claisen rearrangement and 67t- electrocyclisations. Chapter 1 presents an overview of the biological processes responsible for the generation of prenylating agents in Nature and the construction of prenylated phenolic compounds by the convergence of biosynthetic pathways. This is followed by a synopsis of established methods to access prenylated phenols in the laboratory. Chapter 2 focuses on the use of the aromatic Claisen rearrangement to construct prenylated phenols. The Chapter begins with a review of the Claisen rearrangement including mechanistic aspects and the use of this methodology to construct prenylated natural products. The synthesis of two novel prenylated natural products is presented in Section 2.3; the key features of the routes being consecutive chemo- and regio-selective Claisen rearrangements to install the prenyl side-chains and chromene ring. Section 2.4 describes the synthesis of (±)-pestalotheol D, employing a novel modification of the Claisen rearrangement precursor in order to reverse the regioselectivity of the rearrangement. An asymmetric approach is also presented, using a Sharpless asymmetric dihydroxylation to introduce the requisite stereochemistry. (- )-Pestalotheol D was successfully synthesised, confirming the absolute stereochemistry of the natural product. Section 2.4.4 explores this new methodology by means of experimental and theoretical studies of the effect of the modification on regioselectivity in the Claisen rearrangement of meta-allyloxy aryl ketone substrates. Chapter 3 is directed towards the assembly of prenylated phenollc compounds using 67t-electrocyclisations. The Chapter begins with a brief summary of electrocyclisations, followed by highlights from the literature of the syntheses of related natural products. Section 3.3 introduces l,4-thiazine natural products, with exploration of the syntheses of naturally occurring 1,1-dioxo-l,4-thiazines. Studies towards the synthesis of thiaplidiaquinone A are presented in Section 3.4; the initial approach via a bis-phenol is described, utilising a Suzuki-Miyaura cross-coupling to access the key biaryl intermediate. Oxidation of the bis-phenol could not be performed, and this route was subsequently revised in order to incorporate the required hydroxyls; this is examined in Section 3.4.2. The attempted synthesis of aplidinone A is detailed in the next Section, with the conclusion being the synthesis of its thiazine regioisomer. Analysis of the resulting thiazine regiochemistry is discussed using calculations and 2D NMR experiments. Suggestions for related future work on these two projects are outlined at the end of their respective Sections. Chapter 4 details experimental procedures for the chemistry performed throughout the projects.
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Asymmetric phase transfer catalysed Michael additions and their application in synthesisBeynon, Christopher January 2012 (has links)
This thesis describes an investigation into organocatalysed asymmetric Michael additions and their application in synthesis. It focuses primarily on phase transfer catalysed processes, however other modes of catalysis are briefly investigated. Firstly, β-ketoesters derived from 1-indanone and l-tetralone are examined as potential Michael donors. Their addition to methyl vinyl ketone is studied, with a view to producing members of the Gibberellin family. Secondly, the use of an achiral phenoxide "co-catalyst" in conjunction with a chiral quaternary ammonium salt, derived from cinchonidine, is found to produce an effective catalytic species. It is shown to promote the addition of benzophenone glycine imines to a range of Michael acceptors in excellent levels of enantiocontrol (>90% ee). The Michael adducts are then successfully converted to their corresponding 2,5-disubstituted pyrrolidine species, with high maintenance of stereocontrol. A potential application of this co-catalyst methodology is then described in studies towards the synthesis of kaitocephalin.
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