A new concise strategy for synthesis of dibenzo[b,f]thiepins and related fused symmetrical thiepin derivatives

A new strategy for preparation of dibenzob,f]thiepins and related fused systems in good overall yields is described, featuring ortho-metalation of aromatic or heterocyclic aldehyde acetals followed by treatment with bis(phenylsulfonyl) sulfide for construction of the required bis(aryl)- or bis(heteroaryl) sulfide precursors, which were thereafter subjected to deacetalization, and finally McMurry coupling as the ring-forming step.