Sissengaliyeva, Gulsana (2024). Radical-Mediated Reactions Involving Fluorinated Reagents and Sulfones. (Thesis). Universität Bern, Bern
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24sissengaliyeva_g.pdf - Thesis Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND 4.0). Download (23MB) | Preview |
Abstract
Fluorinated compounds hold significant importance across medicinal, agrochemical, and materials chemistry due to their unique impact on the properties of drug candidates. In this context, the first part of the thesis was dedicated to hydroperfluoroaklylation of unactivated alkenes. This is due to a strong demand for selective, general, and efficient techniques to incorporate trifluoromethyl and other perfluoroalkyl groups into compounds. The direct hydroperfluoroalkylation of various unactivated alkenes, including isoprenoid natural products, has been successfully performed. The process occurs at room temperature using commercially available iodoperfluoroalkanes, with 4-tert-butylcatechol as the hydrogen atom source and triethylborane. Additionally, hydrotrifluoromethylation was achieved under similar conditions using gaseous trifluoromethyl iodide, and a straightforward two-step, one-pot hydrotrifluoromethylation method has also been developed using trifluoromethanesulfonyl chloride, which is a convenient source of trifluoromethyl radicals. Next, a single fluorination process was investigated utilising the recently developed N-fluoro-N-arylsulfonamides (NFASs) in the group, representing the third generation of fluorinating agents. This technique facilitated the direct fluorination of secondary and tertiary alkyl iodides and S-alkyl xanthates. Moreover, carbofluorination reactions with unactivated alkenes were successfully carried out under optimised conditions. Due to the versatility of sulfones in organic synthesis, prominently featured in numerous natural compounds and their analogues, the intramolecular 1,5-hydrogen atom transfer (HAT) reactions using a-sulfonyl radicals were investigated as the last part of the thesis. The isomerisation reactions utilising the 1,5-iodine atom transfer (IAT) process and remote C-H functionalisation were successfully executed using α-mono- and bis-sulfonyl radicals across a diverse array of 1-iodoalkyl sulfones. Moreover, allylation and deuteration reactions were explored to analyse the 1,5-HAT translocation patterns, broadening our investigation with α-sulfonyl radicals.
| Item Type: | Thesis |
|---|---|
| Dissertation Type: | Cumulative |
| Date of Defense: | 19 July 2024 |
| Subjects: | 500 Science > 540 Chemistry |
| Institute / Center: | 08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) |
| Depositing User: | Hammer Igor |
| Date Deposited: | 25 Jul 2025 15:01 |
| Last Modified: | 25 Jul 2025 22:25 |
| URI: | https://boristheses.unibe.ch/id/eprint/6508 |
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