SEMINARIO QUÍMICA ORGÁNICA 21-09-20
TÍTULO: "Total Synthesis of (-)-Daphnezomines
A and B"
FUENTE: Guangpeng Xu, Jinbao Wu, Luyang Li, Yunan Lu, Chao Li. J. Am. Chem. Soc. 2020, 142, 36, 15240–15245.
EXPOSITOR: Lic. Nadia L. Martiren
DÍA, HORA y LUGAR: Lunes 21 de septiembre de 2020, 18:00 h, Plataforma MEET GOOGLE.
Link: meet.google.com/bfh-poxv-bso
RESUMEN: Daphnezomines A and B are structurally unusual Daphniphyllum alkaloids
that contain a unique aza-adamantane core skeleton. Herein, a modular approach
to these alkaloids is presented that exploits a diverse array of reaction
strategies. Commencing from a chiral pool terpene–(S)-carvone, the
azabicyclo[3.3.1]nonane backbone, which occurs widely in Daphniphyllum alkaloids,
was easily accessed through a Sharpless allylic amination and a
palladium-catalyzed oxidative cyclization. A protecting group enabled a
stereoselective B-alkyl Suzuki-Miyaura coupling sequence, and an
Fe-mediated hydrogen atom transfer (HAT)-based radical cyclization were then
applied to construct C6 and C8 stereocenters. A final epimer locking strategy
enabled the assembly of the highly congested aza-adamantane core, thereby
achieving the first total synthesis of (-)-daphnezomines A and B in 14 steps.
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