Yescas-Galicia Daniel, Restrepo-Osorio Rodrigo A, García-González Ailyn N, Hernández-Benítez Roberto I, Espinoza-Hicks José C, Escalante Carlos H, Barrera Edson, Santoyo Blanca M, Delgado Francisco, Tamariz Joaquín
Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, 11340 Mexico City, Mexico.
Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Circuito Universitario S/N, 31000 Chihuahua, Chih., Mexico.
J Org Chem. 2022 Oct 7;87(19):13034-13052. doi: 10.1021/acs.joc.2c01563. Epub 2022 Sep 26.
Palladium-catalyzed functionalization was presently performed on two building blocks: 4-oxazolin-2-ones and 4-methylene-2-oxazolidinones. Direct Heck arylation of 4-oxazolin-2-ones led to a series of 5-aryl-4-oxazolin-2-ones, including analogues with N-chiral auxiliary, in an almost quantitative yield. The Pd(II)-catalyzed homocoupling reaction of 4-oxazolin-2-ones provided novel heterocyclic across-ring dienes. Meanwhile, the intramolecular cross-coupling of -aryl-4-methylene-2-oxazolidinones furnished a series of oxazolo[3,4-]indol-3-ones. Further functionalization of 4-methylene-2-oxazolidinones afforded substituted indoles and heterocyclic-fused indoles with aryl, bromo, carbinol, formyl, and vinyl groups. A computational study was carried out to account for the behavior of the formylated derivatives. The currently developed methodology was applied to a new formal total synthesis of ellipticine.
