Site-Selective Silylation of Arenes Mediated by Thianthrene S-Oxide.

The thianthrene S-oxide (TTSO)-mediated site-selective silylation of arenes has been realized via a thianthrenation/Pd-catalyzed silylation sequence. This method features a broad substrate scope and wide functional group tolerance under mild conditions and allows the synthesis of a set of (hetero)arylsilanes with operationally simple manipulations. The application and generality of the approach were further demonstrated by the late-stage functionalization of marketed drugs. This reaction also represents the first example of a Pd-catalyzed silylation reaction of aryl sulfonium salts.