FeCl₂‑Catalyzed Decarboxylative Radical Alkylation/Cyclization of Cinnamamides: Access to Dihydroquinolinone and Pyrrolo[1,2‑<i>a</i>]indole Analogues

A simple and unified method for the synthesis of alkylated dihydroquinolinone and pyrrolo­[1,2-a]­indole derivatives in moderate to high yields (up to 91%) with excellent diastereoselectivity (>20:1 dr) was developed. The inexpensive FeCl2·4H2O works as catalyst, and easily prepared peresters (or peroxides) from aliphatic acids act as alkylating reagents and single electron oxidants. This environmentally friendly reaction proceeds via an FeCl2-catalyzed alkyl radical cascade addition/cyclization fashion.