A catalytic pathway for the conversion of tungsten-silanes into tungsten-silanols

Tungsten substituted silanes C5H5(OC)2(Ph3P)W–SiMe2H (3a), C5Me5(OC)2(Me3P)W–SiMe2H (3b) and C5Me5(OC)2(Me3P)W–SiH3 (6) are converted with urea hydrogenperoxide in the presence of catalytic amounts of MeReO3 to the corresponding metallo-silanols C5H5(OC)2(Ph3P)W–SiMe2OH (4a), C5Me5(OC)2(Me3P)W–SiMe2OH (4b) and C5Me5(OC)2(Me3P)W–Si(OH)3 (7). Condensation of 4b with R3SiCl yields the tungsten-substituted disiloxanes C5Me5(OC)2(Me3P)W–SiMe2OSiR3 (SiR3=SiMe2H (5a), SiCl3 (5b)).