Selenosulfonation: Boron Trifluoride Catalyzed or Thermal Addition of Selenosulfonates to Olefins. A Novel Regio- and Stereocontrolled Synthesis of Vinyl Sulfones.

Article abstract of DOI:10.1021/jo00329a021

Se-Phenyl areneselenosulfonates 1 add to a variety of olefins to produce β-phenylseleno sulfones 2.The reaction may be performed in the presence of boron trifluoride etherate to produce chiefly or exclusively Markovnikov products arising from a stereospecific anti addition.Alternatively, the addition may be thermally induced to afford anti-Markovnikov products generated by a nonstereospecific free-radical process.The two modes of addition achieve complementary regiospecificity.The β-phenylseleno sulfones are converted in high yield to vinyl sulfones by stereospecific oxidation-elimination with m-chloroperbenzoic acid.