A convenient method for construction of polycyclic fused nitrogen-containing heterocycles has been developed. The methodology involves palladium-catalyzed intermolecular carbopalladation-annulation cascade reaction of haloaryl heterocyclic derivatives with different alkynes under relatively mild reaction conditions. Thus, the palladium-catalyzed cascade cyclization of bromophenyl derivatives of indolizine and indole with alkynes afforded tetracycles, possessing a newly formed fused six-membered ring. The reaction of 3-(2-iodobenzyl)-indoles with a variety of alkynes afforded polycyclic compounds with fused seven-membered rings. Annulation with unsymmetrical alkynes exhibited varied regioselectivity. Overall, this approach allows for quick and efficient assembly of polycyclic derivatives of indole and indolizine from easily available precursors.
ASJC Scopus subject areas
- Organic Chemistry