An enantioselective organocatalytic intramolecular ring-closing Friedel-Crafts-type alkylation of indolyl alpha,beta-unsaturated aldehydes has been developed. This powerful new strategy allows enantioselective access to THPIs and THBCs in a straightforward and atom-economical manner.

Pyrano-fused indoles (II) and β-carboline (IV) are formed with high enantiomeric excess. The catalyst system is also active for the cyclization of indole (V) and phenoxy aldehyde (VII) to give the expected fused pyrans. -(LI, C.-F.; LIU, H.; LIAO, J.; CAO, Y.-J.; LIU, X.-P.; XIAO*, W.-J.; Org.