Cyclisation reactions for the synthesis of natural and unnatural piperidines
This work describes the platinum mediated ring opening isomerisation of 2,3-cyclopropanated piperidines, which results in either an endo or exocyclic olefin product. In the case where the beta-hydrogen is absent, a platinum-mediated Wagner-Meerwein type 1,2-alkyl shift reaction is observed. A sere...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2017
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| Online Access: | http://hdl.handle.net/10356/72882 |
| _version_ | 1826113520184328192 |
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| author | Barat, Viktor |
| author2 | Roderick Wayland Bates |
| author_facet | Roderick Wayland Bates Barat, Viktor |
| author_sort | Barat, Viktor |
| collection | NTU |
| description | This work describes the platinum mediated ring opening isomerisation of 2,3-cyclopropanated piperidines, which results in either an endo or exocyclic olefin product.
In the case where the beta-hydrogen is absent, a platinum-mediated Wagner-Meerwein type 1,2-alkyl shift reaction is observed. A serendipitous discovery during a cyclopropanation lead us to Prins reaction under extremely mils condition, furnishing piperidino-dioxanes with complete stereocontrol. This reaction inspires us to pursue the total synthesis of Lupin alkaloids, however it was not compatible with the target alkaloid structures.
The total synthesis of (-)-cytisine was achieved using a stereodivergent 6-endo aza-Michael reaction, which can be utilized for the total synthesis of various piperidine and quinolizidine alkaloids.
During the enantioselective synthesis, we have discovered that our system does not follow the Evans diastereoselective alkylation model, being the first reported example. |
| first_indexed | 2024-10-01T03:24:34Z |
| format | Thesis |
| id | ntu-10356/72882 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:24:34Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | ntu-10356/728822023-02-28T23:36:08Z Cyclisation reactions for the synthesis of natural and unnatural piperidines Barat, Viktor Roderick Wayland Bates School of Physical and Mathematical Sciences DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis DRNTU::Science::Chemistry::Organic chemistry::Heterocyclic compounds This work describes the platinum mediated ring opening isomerisation of 2,3-cyclopropanated piperidines, which results in either an endo or exocyclic olefin product. In the case where the beta-hydrogen is absent, a platinum-mediated Wagner-Meerwein type 1,2-alkyl shift reaction is observed. A serendipitous discovery during a cyclopropanation lead us to Prins reaction under extremely mils condition, furnishing piperidino-dioxanes with complete stereocontrol. This reaction inspires us to pursue the total synthesis of Lupin alkaloids, however it was not compatible with the target alkaloid structures. The total synthesis of (-)-cytisine was achieved using a stereodivergent 6-endo aza-Michael reaction, which can be utilized for the total synthesis of various piperidine and quinolizidine alkaloids. During the enantioselective synthesis, we have discovered that our system does not follow the Evans diastereoselective alkylation model, being the first reported example. Doctor of Philosophy (SPMS) 2017-12-11T03:06:30Z 2017-12-11T03:06:30Z 2017 Thesis Barat, V. (2017). Cyclisation reactions for the synthesis of natural and unnatural piperidines. Doctoral thesis, Nanyang Technological University, Singapore. http://hdl.handle.net/10356/72882 10.32657/10356/72882 en 200 p. application/pdf |
| spellingShingle | DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis DRNTU::Science::Chemistry::Organic chemistry::Heterocyclic compounds Barat, Viktor Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title | Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title_full | Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title_fullStr | Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title_full_unstemmed | Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title_short | Cyclisation reactions for the synthesis of natural and unnatural piperidines |
| title_sort | cyclisation reactions for the synthesis of natural and unnatural piperidines |
| topic | DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis DRNTU::Science::Chemistry::Organic chemistry::Heterocyclic compounds |
| url | http://hdl.handle.net/10356/72882 |
| work_keys_str_mv | AT baratviktor cyclisationreactionsforthesynthesisofnaturalandunnaturalpiperidines |