A catalytic pathway for the conversion of tungsten-silanes into tungsten-silanols
摘要:
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)). (C) 1998 Elsevier Science S.A. All rights reserved.
Synthesis and reactivity of silicon transition metal complexes. 38. Metallo-silanols and siloxanes. 12. C5R5(OC)2(Me3P)M-Substituted silanetriols of molybdenum and tungsten (R = H, Me). Synthesis via oxofunctionalization of metallotrihydridosilanes and transformation into the multifunctionalized metallotetrasiloxane C5Me5(OC)2(Me3P)WSi(OSiMe2H)3
The metallotrihydrosilanes C(5)R(5)(OC)(2)(Me(3)P)MSiH(3) (R = H, Me, M = Mo, W (1a-c)) are converted with dimethyldioxirane to the metallosilanetriols 2a-c. Condensation of 2c with Me(2)Si(H)Cl (3) gives access to the branched Si-H-functionalized metallotetrasiloxane 4.