Synthesis of cyano-substituted carbazoles via successive C–C/C–H cleavage

A highly efficient protocol for the synthesis of polysubstituted cyano carbazoles has been developed. This process is realized through the tandem reactions of Cs2CO3 promoted C–C σ-bond activation of α-cyano ketones followed by Fe-catalyzed selective C–H and/or C–C bond activations. Two of the sp2 C–H bonds are functionalized, and two of the C–C σ-bonds are cleaved involving a 1,2-acyl migration during the reaction process.