Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine
| dc.contributor.advisor | Petersen, Wade | |
| dc.contributor.advisor | Hunter, Roger | |
| dc.contributor.author | Späth, Josef | |
| dc.date.accessioned | 2025-04-08T11:25:58Z | |
| dc.date.available | 2025-04-08T11:25:58Z | |
| dc.date.issued | 2024 | |
| dc.date.updated | 2025-04-07T08:18:55Z | |
| dc.description.abstract | Radical species serve as powerful tools for carbon-carbon bond formation in synthetic organic chemistry. Such species can be formed in an efficient and environmentally friendly manner by way of photoredox catalysis, which uses a photocatalyst in conjunction with visible light (typically) to generate the necessary environment for radical generation under extremely mild conditions. This work outlines the development of a novel imidazolidinone-derived acyl radical, generated under photoredox catalysis, and its application toward the stereoselective synthesis of 3,3- disubstituted oxindoles via an additional-cyclisation cascade sequence to acrylamide precursors. 6 oxindoles were produced in up to 85% yield, with moderate diastereoselectivity of up to 2.2:1, but which could be easily separated by standard chromatography to yield pure diastereomers. Mechanistic studies, by virtue of TEMPO-trapping experiments provided strong support for the existence of the proposed acyl-radical, and further synthetic utility of the research was demonstrated in formal synthesis of the natural product (–)-physovenine, a member of the biologically active cyclotryptamine alkaloids. | |
| dc.identifier.apacitation | Späth, J. (2024). <i>Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine</i>. (). ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/41366 | en_ZA |
| dc.identifier.chicagocitation | Späth, Josef. <i>"Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine."</i> ., ,Faculty of Science ,Department of Chemistry, 2024. http://hdl.handle.net/11427/41366 | en_ZA |
| dc.identifier.citation | Späth, J. 2024. Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine. . ,Faculty of Science ,Department of Chemistry. http://hdl.handle.net/11427/41366 | en_ZA |
| dc.identifier.ris | TY - Thesis / Dissertation AU - Späth, Josef AB - Radical species serve as powerful tools for carbon-carbon bond formation in synthetic organic chemistry. Such species can be formed in an efficient and environmentally friendly manner by way of photoredox catalysis, which uses a photocatalyst in conjunction with visible light (typically) to generate the necessary environment for radical generation under extremely mild conditions. This work outlines the development of a novel imidazolidinone-derived acyl radical, generated under photoredox catalysis, and its application toward the stereoselective synthesis of 3,3- disubstituted oxindoles via an additional-cyclisation cascade sequence to acrylamide precursors. 6 oxindoles were produced in up to 85% yield, with moderate diastereoselectivity of up to 2.2:1, but which could be easily separated by standard chromatography to yield pure diastereomers. Mechanistic studies, by virtue of TEMPO-trapping experiments provided strong support for the existence of the proposed acyl-radical, and further synthetic utility of the research was demonstrated in formal synthesis of the natural product (–)-physovenine, a member of the biologically active cyclotryptamine alkaloids. DA - 2024 DB - OpenUCT DP - University of Cape Town KW - chemistry LK - https://open.uct.ac.za PY - 2024 T1 - Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine TI - Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine UR - http://hdl.handle.net/11427/41366 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/41366 | |
| dc.identifier.vancouvercitation | Späth J. Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine. []. ,Faculty of Science ,Department of Chemistry, 2024 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/41366 | en_ZA |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Department of Chemistry | |
| dc.publisher.faculty | Faculty of Science | |
| dc.subject | chemistry | |
| dc.title | Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine | |
| dc.type | Thesis / Dissertation | |
| dc.type.qualificationlevel | Masters | |
| dc.type.qualificationlevel | MSc |