Synthesis of Bifunctional Silsesquioxanes (RSiMe₂O)_∼4(R′SiMe₂O)_∼4Si₈O₁₂ via Hydrosilylation of Alkenes

In this paper, the effective functionalization of silsesquioxane (HSiMe2O)8Si8O12 (1) via hydrosilylation of two different functional alkenes is presented. For the first time, such a wide spectrum of statistically bifunctional silsesquioxanes (RSiMe2O)∼4(R′SiMe2O)∼4Si8O12 was obtained and characterized. Seventeen new systems with various substituents (Si–H, hydroxyl, ester, epoxy, alkenyl, or alkyl) were prepared by two synthetic approaches. The first method was based on the subsequent hydrosilylation of two alkenes in a one-pot manner, whereas the second one consisted of a two-step protocol in which intermediates (RSiMe2O)∼4(HSiMe2O)∼4Si8O12 were isolated and then reacted with the second alkene, in the presence of the same or a different catalyst. Resulting systems due to the presence of two various groups attached to the silsesquioxane cage can be considered as potential cores for the synthesis of (hyper)branched molecules or macromolecules.