FeCl3-mediated Friedel-Crafts hydroarylation with electrophilic N-acetyl indoles for the synthesis of benzofuroindolines.

IRONic electrophilic indoles! The C3-regioselective hydroarylation of N-acetyl indoles with aromatic nucleophiles mediated by FeCl(3) features a rare example of the electrophilic reactivity of the indole core in a Friedel-Crafts reaction. This indole umpolung allows us straightforward access to the tetracyclic benzofuroindoline motif found in the natural product diazonamide A, which is a potent antitumor agent.