Ligand-Controlled Divergent Cross-Coupling Involving Organosilicon Compounds for Thioether and Thioester Synthesis

A divergent cross-coupling for both thioether and thioester construction from organosilicon compounds has been developed. Predominant selectivity for Hiyama-type coupling and C1 insertion reaction was achieved under the guidance of ligands. Thioether was obtained under ligand-free conditions in which disulfide generated from homocoupling could be prevented. Meanwhile, application of bidentate phosphine ligands under carbon monoxide atmosphere (CO balloon) afforded the thioester with little decomposition, which was revealed through interval NMR tracking

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

Efficient Access to 1,4-Benzothiazine: Palladium-Catalyzed Double C–S Bond Formation Using Na₂S₂O₃ as Sulfurating Reagent

A novel Pd-catalyzed double C–S bond formation coupling reaction has been developed. This protocol, in which Na₂S₂O₃ was used as sulfurating reagent in metal-catalyzed reactions, provides an efficient method for the synthesis of substituted 1,4-benzothiazine derivates, which are structural elements of numerous bioactivity molecules rendering this protocol attractive to both synthetic and medicinal chemistry