Metal-free, one-pot highly selective synthesis of (E)-vinyl sulfones and sulfoxides via addition–oxidation of thiols with alkynes

We have developed a highly selective one-pot method for the synthesis of (E)-vinyl sulfones and sulfoxides from thiols with terminal alkynes. The sulfones and sulfoxides could be obtained with excellent selectivity in good isolated yields. It is simple, efficient and environmentally benign, and metal-free. The mechanism for the formation of the (E)-vinyl sulfones was also proposed.