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Showing 1 to 20 of 60 for “"enantioselective synthesis"”.
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Enantioselective synthesis using bromoacetals.
… of dimethyl tartrate bromoacetals leading to the synthesis of highly functionalised lactones, lactols, epoxides, chiral diacids, diamines, chiral ligands, resolving agents etc are also discussed.
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The enantioselective synthesis of C₁₈-sphingosines
… symmetry-based planning, the stereodivergent synthesis of all sphingosine stereoisomers. This was achieved via the selective preparation of the appropriate diastereomer of azido alcohol (118), were C-4 and C-5 correspond to C-3 and C-2 of the sphingosine skeleton, respectively (Scheme 1).
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Studies towards the enantioselective synthesis of (+)-castanospermine
A study has been carried out on the enantioselective total synthesis of the indolizidine alkaloid (+)-castanospermine. The aim was to develop a convergent synthesis based on a C-8/C-8a disconnection. A distinguishing feature of this method is that it is non-carbohydrate-based.
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Enantioselective Synthesis of Drug-like Molecules via Axially-Chiral Intermediates
… In general, these reactions were highly enantioselective proceeding with little to no loss of enantiomeric excess. Finally, we collaborated with Professor Bloomquist to test the topical toxicity of selected ring-contracted products against adult Anopheles gambiae, the African vector of …
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Enantioselective synthesis of pretomanid & investigations of Raman spectroscopy for through-tube monitoring of reactions
Chapter 1: Enantioselective Synthesis of Pretomanid [color illustrations] Pretomanid is a potential cornerstone active pharmaceutical ingredient for the treatment of tuberculosis (TB). It is found in several advanced clinical trials and can possibly treat all forms of TB. In this report, we discuss …
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Enantioselective synthesis of 2,2,5-Tri- and 2,2,5,5-tetrasubstituted tetrahydrofurans and synthesis of diketopiperazine containing natural products
… cleavage and refunctionalization. A partial synthesis of the bioactive diketopiperazine containing natural product gliocladin C was achieved in nine steps, and 13.4% overall yield. The synthesis featured several novel transformations including the construction of the core structure by an …
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The Use of Ipso-dihydrodiols Enzymatically Derived from Benzoic Acid in Enantioselective Synthesis. Appoaches to Total Synthesis of Vinca Alkaloids
… describe our recent progress in target oriented synthesis of complex organic molecules from aromatic precursors. The latest synthetic approaches toward vinca alkaloids are described and include the construction of model substrates for the investigation into Diels-Alder, radical cascade, and …
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Photoredox activation of SF₆ for fluorination, on-demand automated titration of organometallic reagents in continuous flow, and progress toward an enantioselective synthesis of bedaquiline
… use of SF₆ as a fluorinating reagent in organic synthesis. Photoredox catalysis enables the in situ conversion of SF6, an inert gas, into an active fluorinating species using visible light and photoredox catalysis. Under these conditions, deoxyfluorination of allylic alcohols is affected with …
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Catalytic enantioselective synthesis of oxindoles and benzofuranones bearing a quaternary stereocenter and reactions of palladium bisphosphine complexes relevant to catalytic C-C bond formation
… (Black rearrangement) in a highly efficient and enantioselective manner. The utility of this method is further demonstrated by the formal total synthesis of the natural product aplysin. In Part II reactivity of bisphosphine palladium-complexes is discussed. It is shown that the oxidative addition …
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Nickel-catalyzed intermolecular reductive couplings of alkynes and aldehydes ; Enantioselective synthesis of (-)-terpestacin and structural revision of siccanol using catalytic stereoselective fragment couplings and macrocyclizations
… of cis addition to the alkyne. [Image] ... II. Enantioselective Synthesis of (-)-Terpestacin and Structural Revision of Siccanol Using Catalytic Stereoselective Fragment Couplings and Macrocyclizations. (-)-Terpestacin (1), (naturally occurring enantiomer) and (+)-1 -epi-terpestacin (2) were …
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Enantioselective synthesis and reactivity of bicyclobutanes: strained molecular platforms for 4-, 5-, and 6-membered ring synthesis and rhodium(II)-catalyzed reactions of diazoesters with organozinc reagents
… methodology and its application in the total synthesis of natural products. The results described herein include the development of a new method for enantioselective synthesis of cyclobutanes, the total synthesis of cyclobutane-containing natural products, the development of the first examples …
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Development and application of transition metal-catalyzed cross-coupling reactions
… indoles from aryl halides. Chapter 2. ENANTIOSELECTIVE SYNTHESIS OF INDOLODIOXANE (S)- U86192A The enantioselective synthesis of the antihypertensive agent indolodioxane (S)-U86192A is described. The 4-bromo-5-alkoxy indole, a key intermediate of the synthesis, is prepared according to …
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BINOL-Catalyzed Asymmetric Synthesis of Chiral Heterocycles; Experimental Mechanistic Study of Binol-Catalyzed Conjugate Addition of Vinylboronic Acids to Enones; Enantioselective Synthesis of Diarylalkane Compounds via Binol-Catalyzed Conjugate Addition
… well established method, we investigated the synthesis of a variety of chiral heterocyclic compounds. A new method was developed showing great compatibility with different heteroaryl structures. Along with that, a new BINOL catalyst was introduced that exhibited superior catalytic activity to …
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1. Reinvestigation of a catalytic, enantioselective alkene dibromination and chlorohydroxylation, 2. Double cross-coupling reactions of siloxaborolates, 3. The enantioselective synthesis of 3-substituted morpholines using computer-guided catalyst design
… 1, attempts to reproduce eight, putative, enantioselective dibromination and chlorohydroxylation reactions from oft-cited literature studies are described. The reactions were performed with full fidelity to the original report wherever possible. Analysis of the enantiomeric composition was …
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Approaches toward the enantioselective total synthesis of amarogentic
… different, but complementary strategies for the enantioselective synthesis of the secoiridoid core of amarogentin were evaluated. The first is based on the enantioselective desymmetrisation of meso-anhydrides using titanium TADDOLates. 1,2,4,6-Tetrahydrophthalic anhydride was desymmetrised and …
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The Development of Palladium and Cobalt-Catalyzed Methods for the Syntheses of alpha-Trifluoromethyl and Alkyl Amines
… for the construction of chiral amines in organic synthesis. Amongst these chiral amines, a-trifluoromethyl and alkyl amines are an important subclass that have been sought after because of their relevance in drug discovery. With respect to a-trifluoromethyl amines, the role of fluorine in altering …
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Synthesis and anticancer evaluation of agelastatin alkaloid derivatives and enantioselective total synthesis of aspidosperma alkaloids
I. Synthesis and Evaluation of Agelastatin Derivatives as Potent Modulators for Cancer Invasion and Metastasis The synthesis of new agelastatin alkaloid derivatives and their anticancer evaluation in the context of the breast cancer microenvironment is described. A variety of Ni -alkyl and C5-ether …
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Enantioselective (Formal) Aza-Diels-Alder Reactions with Danishefsky's Diene and Non-Danishefsky Type Dienes
… agents. As a direct result, efforts to develop enantioselective diene-imine (aza-Diels-Alder) reactions to efficiently access these substructures have increased. We have developed highly enantioselective silicon Lewis acid mediated formal aza-Diels-Alder reactions with Danishefsky's diene and …
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A novel, versatile D-BCD steroid construction strategy, illustrated by the total syntheses of estrone and desogestrel
… C14 in a single-pot operation. The racemic total synthesis of desogestrel includes a successful domino anionic cyclisation leading to the formation of the steroid C and B rings in a single operation with complete stereocontrol at C9. The ?-keto phosphonates obtained were subsequently subjected to …
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