text: The S-N bond in sulfenamides are labile in a variety of ways. The sulfur atom tends to be the more electrophilic center of the S-N bond.  Nucleophilic attack on sulfur can occur by amines, by thiols, and by alkyl-magnesium halides which leads to either new sulfenamide compounds or back to starting compounds such as sulfides and disulfides respectively.  Both the nitrogen and sulfur atoms comprising the S-N bond in sulfenamides have lone pairs of electrons in their outer shells, one and two for nitrogen and sulfur respectively.  These lone pairs allow for the possibility of forming either higher order bonds(double, triple) or adding new substituent groups to the compound  For instance the nitrogen in the S-N bond of 2-hydroxysulfenanilides can oxidized to an imine species with sodium dichromate.
  Sulfenamides react with amino-azaheterocycles to form heterocyclic systems (often used as amino protecting groups in various other synthesis reactions). Chlorocarbonylsulfenyl chloride (ClCOSCl) also readily forms S-N bonds with 2-amino-azaheterocycles, but always of a cyclical nature.
  A novel variant of the Appel reaction has been noted for sulfenamides.  Reaction of o-nitrobenzenesulfenamide with PPh and CCl leads the formation of o-nitro-N-(triphenylphosphorany1idene)-benzenesulfenamide.  In this variant reaction the triphenyl phosphine forms a double bonded linkage with nitrogen in the sulfenamide instead of oxygen as is customary in the Appel reaction.  Additionally in the traditional Apple reaction the R-OH bond is cleaved leaving oxygen attached to triphenylphosphine.  In this variant the S-N bond is not cleaved.