A one pot synthesis of annulated carbazole analogs

A ZnBr₂-mediated arylation of N-protected 2/3-bromomethylindoles containing an electron-deficient malonylidene unit with arenes at 80 °C led to the formation of arylated products, which on unprecedented 1,5-sigmatropic rearrangement followed by electrocyclization and subsequent aromatization with loss of diethylmalonate furnished the corresponding annulated carbazoles in reasonable yields.