Synthesis of Functionalized Silsesquioxane Nanomaterials by Rhodium‐Catalyzed Carbene Insertion into Si−H Bonds

Abstract

We report carbene insertion into Si−H bonds of polyhedral oligomeric silsesquioxanes (POSS) for the synthesis of highly functionalized siloxane nanomaterials. Dirhodium(II) carboxylates catalyze insertion of aryl‐diazoacetates as carbene precursors to afford POSS structures containing both ester and aryl groups as orthogonal functional handles for further derivatization of POSS materials. Four diverse and structurally varied silsesquioxane core scaffolds with one, three, or eight Si−H bonds were evaluated with diazo reactants to produce a total of 20 new POSS compounds. Novel diazo compounds containing a fluorinated octyl group and boron‐dipyrromethene (BODIPY) chromophore demonstrate the use of highly functionalized substrates. Transformations of aryl(ester)‐functionalized POSS compounds derived from this method are demonstrated, including ester hydrolysis and Suzuki–Miyaura cross‐coupling.

POSS-Al-porphyrin-imidazolium cross-linked network as catalytic bifunctional platform for the conversion of CO2 with epoxides

“…POSS are a class of organic-inorganic hybrid molecules made by an inorganic nanocaged silicate core surrounded by organic functional groups dangling in a three-dimensional arrangement. In addition, POSS based nanostructures display a good thermal and chemical stability and different applications [36][37][38][39][40][41][42]. The general formula of these hybrid molecules is (R−SiO1.5)n, where n is commonly 6, 8, 10 and 12, the ratio O/Si is 1.5 and R is the vertex functional group (hydrogen, alkyl, alkene, aryl, arylene, etc.).…”