Lewis Acid Mediated One‐Pot Synthesis of Aryl/Heteroaryl‐Fused Carbazoles Involving a Cascade Friedel–Crafts Alkylation/Electrocyclization/Aromatization Reaction Sequence

Abstract A Lewis‐acid‐mediated domino reaction of 2/3‐(bromomethyl)indoles with arenes/heteroarenes led to the formation of the corresponding annulated carbazoles. This three‐step one‐pot transformation proceeds by sequential Lewis acid catalysed Friedel–Crafts alkylation, electrocyclization and aromatization reactions. The strategy is highly efficient for the assembly of complex aryl/heteroaryl‐fused carbazoles.