An efficient method for the preparation of silyl esters of diphosphoric, phosphoric, and phosphorous acid

Tetrakis(trialkylsilyl) diphosphate (alkyl = Me, Et, iPr, tBu) can be obtained in quantitative yield by reacting commercial disodium dihydrogen diphosphate with the respective trialkyl chlorosilane in a triphasic system with formamide. The alkylsilane residues of the diphosphate silyl esters can be either partially or completely hydrolyzed without concurrent cleavage of the P–O–P bond of the diphosphate moiety. The method can be expanded to efficiently produce other persilylated or partially silylated phosphates and phosphites.

Trialkylsilylesters of diphosphate, phosphate, and phosphite are accessible in bulk in quantitative yield by a new triphasic reaction system. Partial/full hydrolysis of the Si–(OP) bonds is possible without affecting the P–O–P bonds. The distribution of partially hydrolyzed esters depends, among other factors, on the silyl migration aptitude.Figure optionsDownload as PowerPoint slide