Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons

Radical and electrophile-promoted nucleophilic closure cascade reactions have been used for the synthesis of polycyclic aromatic hydrocarbons (PAHs) and carbon nanoribbons. Chapter 1 provides a discussion on radical cascade reactions, with a brief history and examples of well documented radical casc...

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Other Authors: Byers, Philip M. (authoraut)
Format: Others
Language:English
English
Published: Florida State University
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Online Access:http://purl.flvc.org/fsu/fd/FSU_migr_etd-7737
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spelling ndltd-fsu.edu-oai-fsu.digital.flvc.org-fsu_2533202020-06-19T03:08:37Z Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons Byers, Philip M. (authoraut) Alabugin, Igor V. (professor directing dissertation) Alamo, Rufina (university representative) Strouse, Geoffrey (committee member) Saha, Sourav (committee member) Department of Chemistry and Biochemistry (degree granting department) Florida State University (degree granting institution) Text text Florida State University Florida State University English eng 1 online resource computer application/pdf Radical and electrophile-promoted nucleophilic closure cascade reactions have been used for the synthesis of polycyclic aromatic hydrocarbons (PAHs) and carbon nanoribbons. Chapter 1 provides a discussion on radical cascade reactions, with a brief history and examples of well documented radical cascade reactions. Investigations into radical chain processes as well as redox processes are discussed. There is much development in these cascades currently due to the complex products that can be formed in a minimal amount of synthetic steps. Chapter 2 discusses the radical cascade that we developed, using a radical chain process. Selective radical generation in conjugated oligomeric o-aryleneethynylenes initiates a cascade which involves five fast radical cyclizations followed by aromatization via a 1,5-H shift to yield PAHs. Computation and 2D NMR studies were performed to determine the final cascade products. Chapter 3 discusses the growing trend in which gold catalysts are used to initiate cascade reactions through an electrophile-promoted nucleophilic closure mechanism. A number of current examples are also provided which demonstrate how gold catalyzed cascade reactions can efficiently synthesize complex PAH molecules. Chapeter 4 demonstrates our approach for the synthesis of fused benzofuran structures through gold catalysis. Through a gold catalyzed electrophile-promoted nucleophilic closure, PAHs containing benzofuran units with a polycyclic aromatic backbone were synthesized through a Sonogashira/5-endo-dig/6-endo-dig cascade. Depending on which mechanism is used, all exo cyclizations can be achieved (radical), or all endo cyclizations (electrophile-promoted nucleophilic closure). Starting materials for either cascade mechanism can be synthesized in a modular fashion, allowing for the systematic and controlled preparation of functionalized PAHs and carbon nanoribbons where, potentially, each of the peripheral aromatic rings can be different. The materials synthesized have future applications in the nano-materials and -electronics industries. Chapter 5 discusses future work in the field of gold catalyzed cascade reactions and provides conclusions on the work presented here within. A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Summer Semester, 2013. June 17, 2013. Carbon, Cascades, Gold, Nanoribbons, PAH, Radicals Includes bibliographical references. Igor V. Alabugin, Professor Directing Dissertation; Rufina Alamo, University Representative; Geoffrey Strouse, Committee Member; Sourav Saha, Committee Member. Chemistry Biochemistry FSU_migr_etd-7737 http://purl.flvc.org/fsu/fd/FSU_migr_etd-7737 This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. http://diginole.lib.fsu.edu/islandora/object/fsu%3A253320/datastream/TN/view/Cascade%20Reactions%20for%20the%20Synthesis%20of%20Polycyclic%20Aromatic%20Hydrocarbons%20and%20Carbon%20Nanoribbons.jpg
collection NDLTD
language English
English
format Others
sources NDLTD
topic Chemistry
Biochemistry
spellingShingle Chemistry
Biochemistry
Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
description Radical and electrophile-promoted nucleophilic closure cascade reactions have been used for the synthesis of polycyclic aromatic hydrocarbons (PAHs) and carbon nanoribbons. Chapter 1 provides a discussion on radical cascade reactions, with a brief history and examples of well documented radical cascade reactions. Investigations into radical chain processes as well as redox processes are discussed. There is much development in these cascades currently due to the complex products that can be formed in a minimal amount of synthetic steps. Chapter 2 discusses the radical cascade that we developed, using a radical chain process. Selective radical generation in conjugated oligomeric o-aryleneethynylenes initiates a cascade which involves five fast radical cyclizations followed by aromatization via a 1,5-H shift to yield PAHs. Computation and 2D NMR studies were performed to determine the final cascade products. Chapter 3 discusses the growing trend in which gold catalysts are used to initiate cascade reactions through an electrophile-promoted nucleophilic closure mechanism. A number of current examples are also provided which demonstrate how gold catalyzed cascade reactions can efficiently synthesize complex PAH molecules. Chapeter 4 demonstrates our approach for the synthesis of fused benzofuran structures through gold catalysis. Through a gold catalyzed electrophile-promoted nucleophilic closure, PAHs containing benzofuran units with a polycyclic aromatic backbone were synthesized through a Sonogashira/5-endo-dig/6-endo-dig cascade. Depending on which mechanism is used, all exo cyclizations can be achieved (radical), or all endo cyclizations (electrophile-promoted nucleophilic closure). Starting materials for either cascade mechanism can be synthesized in a modular fashion, allowing for the systematic and controlled preparation of functionalized PAHs and carbon nanoribbons where, potentially, each of the peripheral aromatic rings can be different. The materials synthesized have future applications in the nano-materials and -electronics industries. Chapter 5 discusses future work in the field of gold catalyzed cascade reactions and provides conclusions on the work presented here within. === A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. === Summer Semester, 2013. === June 17, 2013. === Carbon, Cascades, Gold, Nanoribbons, PAH, Radicals === Includes bibliographical references. === Igor V. Alabugin, Professor Directing Dissertation; Rufina Alamo, University Representative; Geoffrey Strouse, Committee Member; Sourav Saha, Committee Member.
author2 Byers, Philip M. (authoraut)
author_facet Byers, Philip M. (authoraut)
title Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
title_short Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
title_full Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
title_fullStr Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
title_full_unstemmed Cascade Reactions for the Synthesis of Polycyclic Aromatic Hydrocarbons and Carbon Nanoribbons
title_sort cascade reactions for the synthesis of polycyclic aromatic hydrocarbons and carbon nanoribbons
publisher Florida State University
url http://purl.flvc.org/fsu/fd/FSU_migr_etd-7737
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