Direct Cross-Coupling Access to Diverse Aromatic Sulfide: Palladium-Catalyzed Double C–S Bond Construction Using Na2S2O3 as a Sulfurating Reagent

The Pd-catalyzed cross-coupling of aryl halides, alkyl halides, and Na2S2O3·5H2O to deliver aromatic thioethers is described. Pyridine, furan, thiophene, benzofuran, benzoxazole, benzothiophene, benzothiazole, and pyrazine are all amenable to this protocol. The odorless and stable solid Na2S2O3·5H2O was used as a convenient and environmentally friendly source of sulfur. Pd-catalyzed cross-couplings without thiols or thiophenols to build C–S bonds have not previously been achieved, which renders our observation more striking.