Robust Palladium‐Catalyzed Arylation of Catalyst‐Poisoning ortho‐Sulfanyl Aryl Halides with Tetraarylborates and Its Application to Synthesis of π‐Extended Dibenzothiophenes

Abstract Bis(tri‐ tert ‐butylphosphine)palladium‐catalyzed arylation of ortho ‐sulfanyl aryl halides with sodium tetraarylborates proceeds smoothly without any additional bases in high yields, providing a reliable route to 2‐sulfanylbiaryls. The conditions are applicable to aryl chloride and iodide as well as bromides. A variety of functional groups were tolerated. This arylation protocol offers a practical solution to overcome the poisoning behavior of aryl sulfides in such cross‐coupling arylation. In addition, our strategy provides a short and efficient access to dibenzothiophenes in combination with a Pummerer‐type cyclization.