Construction of Functionalized Carbazoles via a [Cp*RhCl2]2-Catalyzed Formal [5+1] Cyclization

A [Cp*RhCl2]2-catalyzed formal [5+1] cyclization of 3-vinylindoles with diazo compounds has been developed for the synthesis of functionalized carbazoles. This strategy involves sequential C-H insertion, Claisen condensation, and aromatization. The advantages of this strategy include easy operation, good yields, mild conditions, and good functional group tolerance.