Trimethylsilyl and Trimethylstannyl Esters of Trithiophosphonic Acid, Starting Compounds for the Synthesis of S-P-Heterocycles

Abstract

Abstract The silyl and stannyl esters of trithiophosphonic acids RP(S)(SEMe3)2 (E=Si, Sn; R=Me, t-Bu) are formed in high yield from the corresponding phosphanes RP(EMe3)2 by the addition of three sulfur atoms (3/8 S8). The stannyl esters can also be obtained from the silyl esters and SnMe3Cl or by reacting dithio=phosphonic acid anhydrides [RP(S)S]2 with (SnMe3)2S. As a result of the pre=formed P-S-bonds and the reactivity of the S-E-bond towards Cl2, Br2 as well as chlorosulfanes SxCl2, the esters represent ideal starting compounds for the synthesis of sulfur-phosphorus-heterocycles of general formulas A and B. The tetrathiadiphosphorinanes [RP(S)S2]2, the products of the reaction with the halogens, are also formed in excellent yield when the silyl esters are treated with dimethylsulfoxide.