Palladium-Catalyzed Conjugate Addition to Electron-Deficient Alkynes with Benzenesulfinic Acid Derived from 1,2-Bis(phenylsulfonyl)ethane: Selective Synthesis of (E)-Vinyl Sulfones

A new, selective method for the synthesis of (E)-vinyl sulfones is presence by palladium-catalyzed C−S bond cleavage/conjugate addition. In the presence of Pd(OAc)2 and DMEDA (N1,N2-dimethylethane-1,2-diamine), 1,2-bis(phenylsulfonyl)ethane underwent the C−S bond cleavage, followed by conjugate addition to numerous electron-deficient alkynes afforded the corresponding (E)-vinyl sulfones in moderate to good yields.