The Reaction of Diethylthiophosphinyl Iodide,Et2P(S)I,with Nucleophiles

The compound Me₂AsSI can exist in two different forms, either as dimethylarsinosulfenyl iodide [or (iodothio)dimethylarsane)], Me₂As–S–I ( A ), or as dimethylthioarsinyl iodide (or dimethylarsinothioic iodide), Me₂As(S)–I ( B ). To confirm that the structure of the product of the reaction between Bunsen's cacodyl disulfide Me₂As(S)–S–AsMe₂ and iodine is A and not B , the known diethylthiophosphinyl iodide (or diethylphosphinothioic iodide), Et₂P(S)–I ( 2 ) was prepared and its hydrolytic stability and reactivity towards a variety of nitrogen, phosphorus(III), arsenic(III), oxygen, and sulfur(II) nucleophiles were studied. The results indicated that only a few reactions of 2 resembled those of A , thus strengthening the proposal that the reaction of Bunsen's cacodyl disulfide with iodine produced A and not B . A series of ³¹P NMR chemical shifts of diethylthiophosphinyl moiety is also reported. Et₂P(S)–DMAP, synthesized and isolated during the presented study, is the ethyl analogue of Me₂P(S)–DMAP, previously described as an important molecule. In our case, Et₂P(S)–DMAP was found to be a good intermediate for the synthesis of phosphoryl or thiophosphoryl derivatives since it was more reactive than 2 towards nucleophiles.