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Showing 1 to 17 of 17 for “"Benzannulation"”.
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The synthesis and benzannulation reactions of (trialkylsilyl)vinylketenes
… This thesis discusses the development of a new benzannulation strategy for the synthesis of phenols based on the reaction of TAS-vinylketenes with lithium ynolates. Studies have shown that the reaction proceeds by formation and electrocyclic ring closure of 3-oxidodienylketene intermediates, …
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Synthesis of indoles via a tandem benzannulation-cyclization strategy
… aniline derivatives. Cyclization of the benzannulation products can then be achieved via several alternate procedures leading to indoles that are highly substituted on the six-membered ring. The cyclization approaches investigated as the second step in this tandem strategy included …
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Synthesis of contorted nanographenes via multi-fold alkyne benzannulation reactions
… employed two-fold InCl3/AgNTf2-catalyzed alkyne benzannulation reaction to afford a broad collection of highly functionalized, laterally π-expanded, [5]helicene-like naphtho[1,2-a]pyrene derivatives in moderate to very good yields. We were able to utilize this method to expand conju-gation of the …
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The Synthesis of Naphthalene-Containing Compounds and Materials Using Benzannulation Reactions
… to access novel aromatic architectures using a benzannulation strategy (Chapter 1). Silyl protected acetylenes are readily reacted to yield the corresponding 2-naphthylsilane. These compounds serve as synthetically useful building blocks for further derivatization and iterative benzannulation to …
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TANDEM BENZANNULATION-CYCLIZATION STRATEGIES FOR THE SYNTHESIS OF HIGHLY SUBSTITUTED INDOLES
Tandem benzannulation-cyclization strategies were developed for the synthesis of highly substituted indoles. The benzannulation strategies involved the reaction of vinylketenes (or aryl ketenes) with ynamides or with ynehydrazides to afford highly substituted phenols via a pericyclic cascade …
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Progress towards the synthesis of tetracyclic heteroaromatic compounds via tandem benzannulation-cyclization strategies
A tandem benzannulation-cyclization strategy was successfully applied to the synthesis of a tetracyclic heteroaromatic compound expected to have interesting electronic properties. Benzannulation of a diazo ketone and a ynamide yielded a highly substituted aniline that was cyclized to indole …
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Synthesis of highly substituted benzo-fused nitrogen heterocycles via tandem benzannulation/cyclization strategies
Benzannulations employing ynamides and vinylketenes (generated in situ from [alpha]-diazo ketones) were investigated. Irradiation of the diazo ketones using a batch or continuous-flow reactor leads to the formation of vinylketenes via a photo-Wolff rearrangement. The vinylketenes then react with …
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I. [2 +2] Cycloaddition and benzannulation of 2-iodoynamides and application to the construction of highly substituted indoles : II. Synthesis of furo[2,3-g]thieno[2,3-e]indole via a benzannulation strategy
… of highly substituted indoles involving this benzannulation reaction were investigated. In addition, the synthesis of furo[2,3-g]thieno[2,3- e]indole, a new tetracyclic aromatic compound, was achieved via a strategy based on benzannulation with ynamides.
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Tandem benzannulation-ring closing metathesis strategy for the synthesis of benzo-fused nitrogen heterocycles ;
A tandem benzannulation-ring closing metathesis strategy for the efficient synthesis of benzo-fused nitrogen heterocycles such as dihydroquinolines, benzazepines, and benzazocines has been developed. This strategy is based on the benzannulation reaction of ynamides with cyclobutenones or …
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Annulation strategies for the synthesis of azulenes and polycyclic nitrogen heterocycles
… forming strategy. The strategy employs a novel benzannulation reaction of substituted cyclobutenones with ynamides, which are synthesized via the strategy for the N-alkynylation of amides strategy developed in the Danheiser laboratory. The products of these benzannulation reactions, …
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I. Persistent radicals for dynamic nuclear polarization : II. Synthesis of substituted indoles
… candidates. Second generation Danheiser benzannulation-tandem cyclization approach was developed and applied toward the synthesis of highly substituted indoles. Substrate synthesis, benzannulation results and product elaboration are described.
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Studies directed toward the total synthesis of salvilenone
… the proposed synthesis involve a regiocontrolled benzannulation involving the photochemical Wolff rearrangement of an a-diazo ketone and an alkoxy acetylene moiety which assembles an aromatic ring in one step from acyclic precursors followed by an intramolecular [4 + 2] cycloaddition of a …
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Approaches Towards a Total Synthesis of Daphenylline
… Heck Reaction, and Intermolecular Diels-Alder/benzannulation strategies. Efforts towards the synthesis of daphenylline’s D ring are discussed. A terse introduction to the scientific literature of daphniphyllum alkaloids and a comprehensive overview of selected approaches and all previous …
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Intramolecular [4+2] cycloadditions of conjugated ynones and related species ; Studies directed toward the total systhesis of glycinoeclepin A
… dihydroisobenzofuran products. A two-step formal benzannulation process generates a tetrahydroanthracene derivative. Ozonolysis of a 7-oxabicycloheptene derivative prepared from a dihydroisobenzofuran affords a product that contains the core oxabicyclo[6.2.1]undecane ring system of eleutherobin …
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Study on cyclization reactions of heterocyclic compounds bearing ethynyl and formyl groups in close proximity to each other /
… mercaptoacetate was able to trigger a novel benzannulation reaction of the starting materials. Novel, concise and regioselective synthetic methods of 5,7–dihydrofuro[3,4–d]pyrimidine, 5H–pyrano[4,3–d]pyrimidine, 1,3–dihydrofuro[3,4–b]quinolines and 1H–pyrano[4,3–b]quinolines frameworks via …
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Investigating the Photophysics of New and Stable Singlet Fission Materials
… to more photostable fission materials: via benzannulation of acenes in TTBP or via excited state aromaticity in INDTs. Our characterisation of TTBP leads to a new design principle for reducing non-radiative voltage losses by maximising photoluminescence yield. The final study on tetracene …
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Design and Development of New Catalytic Carbon-Carbon Bond Forming Reactions: I. N-Heterocyclic Carbene Based Catalytic Platform for Hauser-Kraus Annulations II. Copper-Catalyzed Selective Allylic Alkylation of Allylic Systems Using Grignard Reagents
… development of N-Heterocyclic carbene catalyzed benzannulation will be discussed based on a venerable reaction called the Hauser-Kraus annulation, developed in 1978 by F. M. Hauser and G. A. Kraus. This reaction has enormous utilization in the synthesis of complex natural products with …