(α-Haloalkyl)phosphonium Salts and Sulfur Nucleophiles: A New Type of Reaction Mechanism

Article abstract of DOI:10.1021/jo00233a008

Reaction between (α-haloalkyl)phosphonium salts and some sulfur nucleophiles leads to the substitution product Ph3P⁺CH2SRX^-.Evidence is presented that this substitution is not a normal S_N2 reaction and that it occurs through formation of a phosphonium ylide and a disulfide, reaction between them, and action of the resulting salt on the starting phosphonium salt.Then RSX and Ph3=CH2 reenter the sequence, giving rise to a three-step chain nucleophilic substitution.