The development of radical methodologies for the syntehsis of thiolactones and carbon-sulfer bond formation
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2020Author:
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2024-09-30Citation:
MCCOURT, RUAIR? OLIVER, The development of radical methodologies for the syntehsis of thiolactones and carbon -sulfer bond formation, Trinity College Dublin.School of Chemistry, 2020MCCOURT, RUAIRÍ OLIVER, The development of radical methodologies for the syntehsis of thiolactones and carbon-sulfer bond formation, Trinity College Dublin.School of Chemistry, 2020
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This thesis entitled "The Development of Radical Methodologies for the Synthesis of Thiolactones and Carbon-Sulfur Bond Formation" is divided into 7 chapters in which Chapter 1, the introduction, presents an overview of the thiol-ene and thiol-yne reaction, in particular in an intramolecular context. It also provides a short review of the methods currently available for the synthesis of thiolactones, a fascinating class of compound with far-reaching applications from medicinal chemistry to materials science. Chapter 2 discusses our unsuccessful efforts at developing a thio-Dénès-modified Ueno-Stork cyclization for the synthesis of γ-thiolactones. However, this chapter does contain the first example of the direct radical cyclization of an α-bromo allylic thioester. In Chapter 3 the development of a methodology for the direct radical cyclization of thioacids onto alkenes and alkynes for the synthesis γ-thiolactones is reported. We introduce the acyl thiol-ene (ATE) and acyl thiol-yne (ATY) terminology and expand on the importance of distinguishing these reactions from their non-acyl analogues with support from computational studies of the ATE cyclization reaction. Divulged in Chapter 4 is a strategy for the synthesis of δ-thiolactones based on the ATE reaction of γ-alkenyl esters followed by Steglich thiolactonization. γ-Alkenyl esters may also be converted to γ-thiolactone, thus allowing for divergent approach to both compound classes. Chapter 5 exploits atmospheric oxygen as an initiator for the intermolecular thiol-ene reaction, proving capable of generating thiyl radicals from thioacids, alkanethiols and thiophenols to generate a plethora of robust thioester and thioether linkages. In this chapter we report our optimization of this reaction process and conduct a concise mechanistic study which validates our proposed radical mechanism. Furthermore, we also conduct a near exhaustive examination of the scope of this reaction in terms of functional group compatability. Chapter 6 gives overall conclusions on the results and methodological advancements obtained from the previous chapters. Finally, Chapter 7 comprises the experimental procedures for the synthesis of all the compounds described in the previous chapters, as well as the methods used for the different techniques employed.
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School of Chemistry and Chemical Biology
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https://tcdlocalportal.tcd.ie/pls/EnterApex/f?p=800:71:0::::P71_USERNAME:MCCOURRODescription:
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Author: MCCOURT, RUAIRÍ OLIVER
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Scanlan, EoinPublisher:
Trinity College Dublin. School of Chemistry. Discipline of ChemistryType of material:
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Radical, Methodology, ThiolactoneMetadata
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