Concise Enantioselective Total Synthesis of Daphenylline Enabled by an Intramolecular Oxidative Dearomatization.
J Am Chem Soc
; 144(13): 5750-5755, 2022 04 06.
Article
en En
| MEDLINE
| ID: mdl-35289615
Daphenylline is a structurally unique member of the triterpenoid Daphniphyllum natural alkaloids, which exhibit intriguing biological activities. Six total syntheses have been reported, five of which utilize aromatization approaches. Herein, we report a concise protecting-group-free total synthesis by means of a novel intramolecular oxidative dearomatization reaction, which concurrently generates the critical seven-membered ring and the quaternary-containing vicinal stereocenters. Other notable transformations include a tandem reductive amination/amidation double cyclization reaction, to assemble the cage-like architecture, and installation of the other two chiral stereocenters via a highly enantioselective rhodium-catalyzed challenging hydrogenation of the diene intermediate (90% e.e.) and an unprecedented remote acid-directed Mukaiyama-Michael reaction of the complex benzofused cyclohexanone (13:1 d.r.).
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Alcaloides
Idioma:
En
Revista:
J Am Chem Soc
Año:
2022
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Estados Unidos