Base-controlled divergent synthesis of vinyl sulfones from (benzylsulfonyl)benzenes and paraformaldehyde.

A tuneable metal-free protocol for the selective preparation of α-substituted vinyl sulfone and (E)-vinyl sulfone derivatives has been described. In this process, stable paraformaldehyde was used as the carbon source. The base played an important role in the selectivity control of transformation. More than 50 products were synthesized with excellent chemoselectivity and broad functional group tolerance.