An efficient two-step approach, comprising the Friedel-Crafts
reaction of 2-bromobenzoyl chlorides with indoles to give 3-(2-bromobenzoyl)indoles
and their palladium-catalyzed intramolecular direct arylation to
give indenoindolones, has been developed. 3-(2-Bromobenzoyl)indoles
were crucial intermediates; the method was successful with N-unprotected
or N-protected indoles. This approach affords a convenient preparation
of diverse substituted and functionalized indenoindolones in good
to high yields from easily accessible starting materials. Several
moieties, which are commonly integrated into bioactive compounds,
can be incorporated with ease by this synthesis.
acylation - arylation - catalysis - coupling - heterocycles - indoles - Lewis acids
- palladium
