RhIII-Catalyzed Synthesis of Cyclopenta[b]carbazoles via Cascade C-H/C-C Bond Cleavage and Cyclization Reactions: Using Amide as a Traceless Directing Group.

Rhodium-catalyzed cascade C-H/C-C cleavage and cyclization reactions of 3-amide substituted indoles with diynes to construct cyclopenta[b]carbazoles have been developed. A strategy amide worked as a novel traceless directing group along with C-C bond cleavage via Friedel-Crafts-retro reaction has been disclosed in this protocol. This method exhibits a broad substrate scope and tolerates various functional groups, furnishing the carbazole derivatives in good to high yields.