Stereochemistry of Aryl Methyl Phosphorochloridothionates as Chiral Two-step Phosphorylating Reagents

Seven aryl methyl phosphorochloridothionates were prepared and examined for reactivity as two-step phosphorylating reagents to synthesize oxazaphospholidine sulfide. The 2,6-dichloro-4-methylphenyl and p-nitrophenyl derivatives (CMPC and MNPC) were selected and resolved into optically active enantiomers. Their absolute configurations were determined. Even in the presence of an alcohol, an amine first attacked the phosphorus displacing the chloride ion. The amide that was produced reacted with an alkoxide to displace the aryloxide ion. Both the substitutions underwent inversion of the configuration.