Résumé
•A functional laddersiloxane bearing four vinyl groups on the T4 unit is prepared.•The vinyl groups undergo quantitative hydrosilylation thanks to very low Pt loadings.•Tetrachloro laddersiloxanes are prepared in very high yields.•The laddersiloxanes reported are promising precursors for hybrid materials.
A straightforward, efficient and scalable (gram scale) route to an unprecedented 6–8–6 laddersiloxane 3 bearing four vinyl groups on the cyclotetrasiloxane T4 unit is reported. Compound 3 was fully characterized by multinuclear NMRs, mass spectrometry, and its structure was determined by X-ray crystallography. The reactivity of the vinyl functions was next explored and hydrosilylations of 3 were successfully achieved with three different silanes in the presence of a small amount of Pt catalyst (0.025 mol% of Pt per vinyl function) in each case. The resulting laddersiloxanes were isolated in high yields (76 to 99%) after straightforward work-ups and fully characterized. With its high thermal stability (Td5 = 372 °C) and chemical versatility, 3 thus appears as a promising precursor for building hybrid materials.
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