Oxidative Furan-to-Indole Rearrangement. Synthesis of 2‑(2-Acylvinyl)indoles and Flinderole C Analogues

Oxidative rearrangement of 2-(2-aminobenzyl)­furans
affording 2-(2-acylvinyl)­indoles
in a stereocontrolled manner in good-to-excellent yields has been
developed. Thus, (2-aminobenzyl)­furans with electron-releasing alkoxy
substituents in the phenyl group form only E-isomers
of 2-(2-acylvinyl)­indoles. Conversely, substrates without such substituents
produce target products as Z-isomers exclusively.
A short diastereoselective method for the transformation of the obtained
2-(2-acylvinyl)­indoles into antimalarial bisindole alkaloid flinderole
A–C analogues has been developed.