Synthesis of Dibenzothiophenes and Carbazoles by Sequential 'Tetra-Fold Heck/6 π-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 6π-electrocyclization and dehydrogenation. A number of reactions could be successfully carried out as domino reactions in only one synthetic step. [ABSTRACT FROM AUTHOR]