Gold-Catalyzed Conjugate Addition Type Reaction of Indoles with α,β-Enones

3-Unsubstituted indoles undergo regioselective alkylation at the 3-position of the indole nucleus through gold-catalyzed conjugated addition type reaction with α,β-enones. 3-Substituted indoles undergo C-2 alkylation. Sequential C-3/C-2 gold catalyzed alkylation of the indole with dibenzylidene acetone gives a poly­cyclic indole b-annulated with a seven-membered cycle