Synthesis of Dibenzothiophenes and Carbazoles by Sequential 'Tetra-Fold Heck/6π-Electrocyclization/Dehydrogenation' Reactions of Tetrabromothiophene and Tetrabromo-N-methylpyrrole

Dibenzothiophenes and carbazoles were prepared by tetrafold Heck reactions of tetrabromothiophene and N-methyltetrabromopyrrole and subsequent 6p-electrocyclization and dehydrogenation. A number of reactions could be successfully carried out as domino reactions in only one synthetic step.