Reactions des derives du phosphore trivalent avec les composes a halogene positif—II : Phosphites d'alcoyle et α-cyano α-haloesters: Synthese et reactivite de cetenimines n-phosphoryles

Trialkylphosphites P(OR)₃ react with substituted α-cyano α-haloesters by initial attack of the phosphorous compound at the halogen atom to give N-phosphorylated ketenimines or a mixture of ketenimines and vinylphosphates when R = Me ou Et The reaction occurs via an intermediate ion pair. Nucleophiles (water, methanol, amines, carbanions) react with ketenimines in two ways: a phosphoryl displacement and an addition of the nucleophilic reagent. In the latter, ketenimines yield phosphoramides which, according to the nature of the substituants attached to the initial esters, can be converted into heterocycles (Δ₂ pyrrolines, pyrrolidines, furans).