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Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products
Triterpenoid natural products from the Schisandraceae family have long presented a significant synthetic challenge. Lancifodilactone I, a member of the family not previously synthesized, was identified as a key natural product target, from which many other members could be synthesized. We envisaged...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10254518/ https://www.ncbi.nlm.nih.gov/pubmed/37298943 http://dx.doi.org/10.3390/molecules28114468 |
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author | Kravljanac, Pavle Anderson, Edward A. |
author_facet | Kravljanac, Pavle Anderson, Edward A. |
author_sort | Kravljanac, Pavle |
collection | PubMed |
description | Triterpenoid natural products from the Schisandraceae family have long presented a significant synthetic challenge. Lancifodilactone I, a member of the family not previously synthesized, was identified as a key natural product target, from which many other members could be synthesized. We envisaged that the core ring system of lancifodilactone I could be accessed by a strategy involving palladium-catalysed cascade cyclisation of a bromoenynamide, via carbopalladation, Suzuki coupling and 8π-electrocyclisation, to synthesize the core 7,8-fused ring system. Exploration of this strategy on model systems resulted in efficient syntheses of 5,6- and 5,8-fused systems in high yields, which represent the first such cyclisation where the ynamide nitrogen atom is ‘external’ to the forming ring system. The enamide functionality resident in the cascade cyclisation product was found to be less nucleophilic than the accompanying tri-/tetrasubstituted alkene(s), enabling regioselective oxidations. Application of this strategy to 7,6-, and 7,8-fused systems, and ultimately the ‘real’ substrate, was ultimately thwarted by the difficulty of 7-membered ring closure, leading to side product formation. Nevertheless, a tandem bromoenynamide carbopalladation, Suzuki coupling and 6/8π-electrocyclisation was shown to be a highly efficient tactic for the formation of bicyclic enamides, which may find applications in other synthetic contexts. |
format | Online Article Text |
id | pubmed-10254518 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-102545182023-06-10 Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products Kravljanac, Pavle Anderson, Edward A. Molecules Article Triterpenoid natural products from the Schisandraceae family have long presented a significant synthetic challenge. Lancifodilactone I, a member of the family not previously synthesized, was identified as a key natural product target, from which many other members could be synthesized. We envisaged that the core ring system of lancifodilactone I could be accessed by a strategy involving palladium-catalysed cascade cyclisation of a bromoenynamide, via carbopalladation, Suzuki coupling and 8π-electrocyclisation, to synthesize the core 7,8-fused ring system. Exploration of this strategy on model systems resulted in efficient syntheses of 5,6- and 5,8-fused systems in high yields, which represent the first such cyclisation where the ynamide nitrogen atom is ‘external’ to the forming ring system. The enamide functionality resident in the cascade cyclisation product was found to be less nucleophilic than the accompanying tri-/tetrasubstituted alkene(s), enabling regioselective oxidations. Application of this strategy to 7,6-, and 7,8-fused systems, and ultimately the ‘real’ substrate, was ultimately thwarted by the difficulty of 7-membered ring closure, leading to side product formation. Nevertheless, a tandem bromoenynamide carbopalladation, Suzuki coupling and 6/8π-electrocyclisation was shown to be a highly efficient tactic for the formation of bicyclic enamides, which may find applications in other synthetic contexts. MDPI 2023-05-31 /pmc/articles/PMC10254518/ /pubmed/37298943 http://dx.doi.org/10.3390/molecules28114468 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Kravljanac, Pavle Anderson, Edward A. Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title | Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title_full | Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title_fullStr | Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title_full_unstemmed | Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title_short | Synthetic Study toward Triterpenes from the Schisandraceae Family of Natural Products |
title_sort | synthetic study toward triterpenes from the schisandraceae family of natural products |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10254518/ https://www.ncbi.nlm.nih.gov/pubmed/37298943 http://dx.doi.org/10.3390/molecules28114468 |
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