Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles
<p><strong>Chapter 1: Introduction.</p></strong> <p>The introduction covers an overview of hydrogen borrowing and the types of hydrogen borrowing strategies. The challenges and advantages of hydrogen borrowing strategies. The structure of Ph* ketones and how this can be...
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| Format: | Abschlussarbeit |
| Sprache: | English |
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2023
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| _version_ | 1826316834231549952 |
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| author | Lunt-Laurin, CE |
| author2 | Donohoe, T |
| author_facet | Donohoe, T Lunt-Laurin, CE |
| author_sort | Lunt-Laurin, CE |
| collection | OXFORD |
| description | <p><strong>Chapter 1: Introduction.</p></strong>
<p>The introduction covers an overview of hydrogen borrowing and the types of hydrogen borrowing strategies. The challenges and advantages of hydrogen borrowing strategies. The structure of Ph* ketones and how this can be utilised in synthesis.</p>
<p><strong>Chapter 2: Synthesis of piperidines by hydrogen borrowing.</p></strong>
<p>Synthesis of C–C and C–N bond formation via hydrogen borrowing is well established. In this Chapter, we outline how Ph* ketone can be used to synthesise stable α-aminoketones allowing the two strategies to be combined to form piperidines via a [4+2] strategy in up to 66% yield.</p>
<p><strong>Chapter 3: Synthesis of γ-lactones by alkylation with 1,2-diols.</p></strong>
<p>In this Chapter, the synthesis of γ lactones is discussed using a hydrogen borrowing reaction followed by cleavage of Ph* ketone. Both reactions were performed in high yield, and by modifying the established Ph* cleavage conditions, lactones could be formed with 96% e.s.</p>
<p><strong>Chapter 4: Synthesis of cyclohexenes by a Mukaiyama-Michael Addition and 1,5-Hydride Shift sequence.</p></strong>
<p>The synthesis of cyclohexenes by 1,5-hydride transfer is of ongoing interest to us. In this Chapter, we combine this reaction with Mukaiyama-Michael additions to access enantioenriched cyclohexenes. We then explore how tri-substituted THP rings behave, allowing us to access di-substituted cyclohexenes with both retention and inversion of the stereochemistry.</p>
<p><strong>Chapter 5: Development of catalytic aluminium 1,5-hydride shift reactions.</p></strong>
<p>Using (super)stoichiometric aluminium alkoxides in 1,5-hydride transfer reactions severely limits their synthetic utility. By preventing the condensation step, we were able to perform hydride transfers with 81% yield using 20 mol% loadings. We found that stepwise cyclisation allows access to the desired enone, skipped enone and chromenes.</p>
<p><strong>Chapter 6: Experimental Procedures.</p></strong>
<p>This chapter contains all experimental procedures and structural information of compounds discussed in the chapters above.</p>
<p><strong>Chapter 7: Appendix.</p></strong>
<p>This section summarises the group's understanding of aluminium's role in 1,5-hydride transfer. The X-ray crystal structures of compounds 3-58, 4-138 and 4-165 can be found here.</p>
<p><strong>References.</p></strong>
<p>References for all chapters of the thesis are collated here.</p> |
| first_indexed | 2024-09-25T04:08:06Z |
| format | Thesis |
| id | oxford-uuid:e29a1f53-b006-4d75-b5b1-1e72c2b1474a |
| institution | University of Oxford |
| language | English |
| last_indexed | 2025-02-19T04:29:06Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | oxford-uuid:e29a1f53-b006-4d75-b5b1-1e72c2b1474a2024-12-12T07:57:08ZApplications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocyclesThesishttp://purl.org/coar/resource_type/c_db06uuid:e29a1f53-b006-4d75-b5b1-1e72c2b1474aChemistry, OrganicEnglishHyrax Deposit2023Lunt-Laurin, CEDonohoe, T<p><strong>Chapter 1: Introduction.</p></strong> <p>The introduction covers an overview of hydrogen borrowing and the types of hydrogen borrowing strategies. The challenges and advantages of hydrogen borrowing strategies. The structure of Ph* ketones and how this can be utilised in synthesis.</p> <p><strong>Chapter 2: Synthesis of piperidines by hydrogen borrowing.</p></strong> <p>Synthesis of C–C and C–N bond formation via hydrogen borrowing is well established. In this Chapter, we outline how Ph* ketone can be used to synthesise stable α-aminoketones allowing the two strategies to be combined to form piperidines via a [4+2] strategy in up to 66% yield.</p> <p><strong>Chapter 3: Synthesis of γ-lactones by alkylation with 1,2-diols.</p></strong> <p>In this Chapter, the synthesis of γ lactones is discussed using a hydrogen borrowing reaction followed by cleavage of Ph* ketone. Both reactions were performed in high yield, and by modifying the established Ph* cleavage conditions, lactones could be formed with 96% e.s.</p> <p><strong>Chapter 4: Synthesis of cyclohexenes by a Mukaiyama-Michael Addition and 1,5-Hydride Shift sequence.</p></strong> <p>The synthesis of cyclohexenes by 1,5-hydride transfer is of ongoing interest to us. In this Chapter, we combine this reaction with Mukaiyama-Michael additions to access enantioenriched cyclohexenes. We then explore how tri-substituted THP rings behave, allowing us to access di-substituted cyclohexenes with both retention and inversion of the stereochemistry.</p> <p><strong>Chapter 5: Development of catalytic aluminium 1,5-hydride shift reactions.</p></strong> <p>Using (super)stoichiometric aluminium alkoxides in 1,5-hydride transfer reactions severely limits their synthetic utility. By preventing the condensation step, we were able to perform hydride transfers with 81% yield using 20 mol% loadings. We found that stepwise cyclisation allows access to the desired enone, skipped enone and chromenes.</p> <p><strong>Chapter 6: Experimental Procedures.</p></strong> <p>This chapter contains all experimental procedures and structural information of compounds discussed in the chapters above.</p> <p><strong>Chapter 7: Appendix.</p></strong> <p>This section summarises the group's understanding of aluminium's role in 1,5-hydride transfer. The X-ray crystal structures of compounds 3-58, 4-138 and 4-165 can be found here.</p> <p><strong>References.</p></strong> <p>References for all chapters of the thesis are collated here.</p> |
| spellingShingle | Chemistry, Organic Lunt-Laurin, CE Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title | Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title_full | Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title_fullStr | Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title_full_unstemmed | Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title_short | Applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| title_sort | applications of pentamethyl phenyl ketones in the synthesis of carbocycles and heterocycles |
| topic | Chemistry, Organic |
| work_keys_str_mv | AT luntlaurince applicationsofpentamethylphenylketonesinthesynthesisofcarbocyclesandheterocycles |