Cascade Amination/Cyclization/Aromatization Process for the Rapid Construction of [2,3-c]Dihydrocarbazoles and [2,3-c]Carbazoles

An intramolecular cascade amination/cyclization/aromatization reaction of functionalized alkylidenecyclopropanes has been developed in the presence of silver acetate, affording a variety of [2,3-c] dihydrocarbazoles and [2,3-c]carbazoles in moderate to excellent yields. The mechanistic investigations revealed that this cascade reaction proceeds through a radical initiated process. Moreover, further transformations for the synthesis of eustifoline-D and an OLED exhibit a potential synthetic utility of this method.