Spectral study of interaction between allyl ethers and hydrosiloxanes

Interaction of allyl ethers with hydrosiloxanes in the presence of metal complexes has been investigated by spectral methods (¹H NMR, IR, and GC-MS) as well as by gas-liquid chromatography. It has been shown that the anti-Markovnikov addition predominantly occurs in the studied cases; disproportionation of siloxanes and migration of double bond in the ethers have been identified as side reactions. The tendency to enter the side reactions has decreased in the following series: (HMeSiO)₄ > HMe₂Si(OSiMe₂)₂H ≈ HMe₂SiOSiMe₃ > (HMe₂Si)₂O > (Me₃SiOSiMeH)₂O. The general scheme of disproportionation of siloxanes HMe₂Si(OSiMe₂) _n H (n ≥ 1) has been proposed. According to mass spectrometry data, the silicon-containing fragment majorly contributes to the fragmentation of hydrosilylation products. Fragmentation of the γ,γ-adducts is similar to that of γ-adducts. The predominant direction of fragmentation in the products of β,γ-addition of HMe₂Si(OSiMe₂)nH (n = 1–3) to allyl ethers is determined by fragmentation of the γ-component of the molecule. The scheme of fragmentation of the hydrosilylation products ions has been proposed.