of main observation and conclusion Site-selective borylation of simple arenes was realized in one pot via an electrophilic thianthrenation/Pd-catalyzed borylation sequence. The key to achieve this operatically simple process is the use of Pd catalysis, which could tolerate the solvent and acidic conditions used in the thianthrenation step. This protocol features mild conditions, broad functional group tolerance, and simple manipulations, and is suitable for late-stage functionalization of a wide range of pharmaceuticals and complex bioactive molecules.

A novel transient SET mediator approach has been developed for the photoinduced radical-radical cross coupling reaction. Using the in-situ generated thianthrene radical cation as the transient SET mediator, the thiocyanation and selenocyanation of aryl thianthrenium salts have been realized under the mild conditions in the absence of the photocatalyst or single electron donor. In comparison with the photocatalyst enabled process, the protocol features mild conditions, simple manipulation, a broad substrate scope, excellent functional group and heterocycle tolerance. Due to the feasible accessibility of aryl thianthrenium salts, this method has also been applied in the efficient synthesis of a bioactive molecule, and the late-stage functionalization of complex arenes.