12° SEMINARIO QUÍMICA ORGÁNICA IQUIR 2023

SEMINARIO QUÍMICA ORGÁNICA 07-08-23

EXPOSITOR: Dr. Teodoro S. Kaufman

TÍTULO: "Enantioselective Synthesis of (+)-Peganumine A".

FUENTE: Cyril Piemontesi, Qian Wang, and Jieping Zhu, J. Am. Chem. Soc. 2016, 138, 11148−11151.

DÍA, HORA y LUGAR: Lunes 7 de agosto de 2023, 14:00 h, Aula 18 y virtual.

Modalidad virtual, Link: meet.google.com/hjn-ygro-twf (Plataforma MEET GOOGLE)

Resumen: A gram-scale enantioselective total synthesis of (+)-peganumine A was accomplished in 7 steps from commercially available 6-methoxytryptamine. Key steps included (a) a Liebeskind−Srogl cross-coupling; (b) a one-pot construction of the tetracyclic skeleton from an ω-isocyano-γ-oxo-aldehyde via a sequence of an unprecedented C−C bond forming lactamization and a transannular condensation; (c) a one-pot organocatalytic process merging two achiral building blocks into an octacyclic structure via a sequence of enantioselective Pictet−Spengler reaction followed by a transannular cyclization. This last reaction created two spirocycles and a 2,7-diazabicyclo[2.2.1]heptan-3-one unit with excellent control of both the absolute and relative stereochemistry of the two newly created quaternary stereocenters.