Switchable Copper-Catalyzed Approach to Benzodithiole, Benzothiaselenole, and Dibenzodithiocine Skeletons

A copper-catalyzed reaction between 2-bromo-benzothioamides and S8 or Se involving sulfur rearrangement is reported, enabling access to benzodithioles 2 and benzothiaselenoles 6 in the presence of Cs2CO3. In the absence of S8 or Se, the reaction affords dibenzodithiocines 7 via two consecutive C(sp2)-S Ullmann couplings.
QC 20200716