Sulphene–tertiary amine zwitterions: intermediates in the multiexchange of hydrogen in a sulphene reaction

Abstract

With sterically unhindered tertiary amines and deuterium oxide or other deuteriated sulphene traps, alkanesulphonyl halides with more than one α-hydrogen may yield products having more than one of the α-hydrogens exchanged; evidence is presented for a mechanism involving reaction of the intermediate sulphene with the amine to form a zwitterion ([graphic omitted]HR¹SO₂[graphic omitted]R₃²) which may then exchange hydrogens via its conjugate acid.