Differences in mechanisms of nucleophilic substitution at phosphorus in S-alkyl alkylphosphonothioates and S-alkyl phosphorothioates
Abstract
Whereas most phosphono-derivatives are hydrolysed more rapidly by hydroxide than the corresponding phosphoro-derivatives, the reverse situation holds for S-alkyl phosphonothioates and S-alkyl phosphorothioates; this reversal of the more usual pattern may be related to a stereochemical difference in that nucleophilic substitution in S-alkyl alkylphosphonothioates proceeds with inversion of configuration, whereas retention of configuration is observed for similar reactions with S-alkyl phosphorothioates.