New rearrangement of triphenyl(triphenylsilylperoxy)germane catalyzed by nucleophiles

The peroxide Ph₃GeOOSiPh₃ rearranges in THF solution at ca. 20°C in the presence of fluoride ions or triethylamine to the germasiloxane, Ph₂(PhO)GeOSiPh₃, while thermal rearrangement of the same peroxide gives Ph₃GeOSi- (OPh)Ph₂. The reaction of tris(trimethylsilylmethyl)stannyllithium (I) with one equivalent of the germasiloxane Ph₂(PhO)GeOSiPh₃ in THF yields (Me₃SiCH₂)₃SnPh, (Ph₂GeX)_x and Ph₃SiOLi. Analogous products have been obtained in high yield in the reactions of I with the peroxides Ph₃GeOOSiPh₃ and Ph₃GeOOSiMe₃. It is assumed that the initial step of these reactions is rearrangement of the peroxides, catalyzed by (Me₃SiCH₂)₃Sn anions, with the formation of the germasiloxanes Ph₂(PhO)GeOSiR₃ (R = Ph or Me). The mechanism of this catalytic rearrangement of unsymmetrical peroxides is discussed.