Darstellung und oxidative Derivatisierung von Dialkylthiophosphiten

Preparation and Oxidative Derivatisation of Phosphonothionic Esters The kind of the amine used influences decisively course and rate of the reaction of trialkyl phosphites, (RO)₃P (R = Me, Et, Ph) with H₂S in the presence of different amines (Et₃N, Et₂NH, Et₂NPh, pyridine). Phosphonothionic esters, (RO)₂P(S)H (R = Me, Et, Bu), are obtained in over 80% yield by using pyridine as base and an alkali alcoholate as catalyst. The oxidative derivatisation of phosphonothionic esters by means of CCI₄ and protic (4-nitrophenol, 2,4,5-trichlorophenol, ammonia, piperidine, phenylhydrazine) or anionic nucleophiles (F^?, NCS^?, NCO^?, CN^?, N₃^?) (Atherton-Todd reaction) yields thiophosphoric acid derivatives (RO)₂P(S)Nuc (R = Me, Et, Bu: Nuc = 4-nitrophenoxy, PhNHNH; R = Me, Et: Nuc = 2,4,5-trichlorophenoxy, F, NCS, N₃; R = Me: NH₂, C₅H₁₀N; R = Et: Nuc = CI, CN) and in some cases the dealkylated products (RO)P(Nuc)SO^? (R = Me; Nuc = CI, F, NCS, CN). The phosphazenes (EtO)₂P(S)? N = PPh₃ and (MeO)₂P(S)? N ? P(OEt)₃, up to now unknown in literature, were obtained by treating thiophosphoryl azides with PPh₃ or P(OEt)₃, resp.