Tris(trimethylsilyl) Phosphite

Abstract

[1795-31-9] C9H27O3PSi3 (MW 298.60) InChI = 1S/C9H27O3PSi3/c1-14(2,3)10-13(11-15(4,5)6)12-16(7,8)9/h1-9H3 InChIKey = VMZOBROUFBEGAR-UHFFFAOYSA-N (preparation of bis(trimethylsilyl) phosphonate esters by the Arbuzov reaction with halogen-containing compounds or by the Abramov reaction with carbonyl compounds, followed by facile hydrolysis to the corresponding phosphonic acids, RP(O)(OH)2) Physical Data: bp 84 °C/5 mmHg,2 86.5 °C/18 mmHg,3 83–84 °C/16 mmHg,4 90–92 °C/16 mmHg,4 78–81 °C/8 mmHg; d 0.893 g cm−3. Form Supplied in: liquid; commercially available. Preparative Method: by silylation of anhydrous phosphorous acid (dried by repeated azeotropic evaporation of a solution in THF with dry benzene) with excess Chlorotrimethylsilane and excess Triethylamine in dimethoxyethane,2 toluene,3 or Et2O–THF,5 followed by evaporation of the solvent and vacuum distillation of the residue. The residue, which contains a mixture of tris(trimethylsilyl) phosphite and bis(trimethylsilyl) phosphonate [HP(O)(OTMS)2], can also be heated with sodium (140 °C, 13–22 h), followed by vacuum distillation to obtain pure tris(trimethylsilyl) phosphite.4 Purification: vacuum distill before use. Handling, Storage, and Precautions: extremely hygroscopic; use in a fume hood.