Selective Hydrosilylation of Alkynes with Octaspherosilicate (HSiMe2O)8Si8O12

Abstract

Comprehensive studies on platinum‐catalyzed hydrosilylation of a wide spectrum of the terminal and internal alkynes with spherosilicate (HSiMe2O)8Si8O12 (1a) were investigated. The influence of the reaction parameters, and the types of reagents and catalysts on the efficiency of the process, which enabled the creation of a versatile and selective method to synthesize olefin octafunctionalized octaspherosilicates, was studied in detail. Within this work, twenty novel 1,2‐(E)‐disubstituted and 1,1,2‐(E)‐trisubstituted alkenyl‐octaspherosilicates (3a‐m, 6n‐t) were selectively obtained with high yields, and fully characterized (1H, 13C, 29Si NMR, FT‐IR, MALDI TOF or TOF MS ES+). Moreover, the molecular structure of the compound (Me3Si(H)C=C(H)SiMe2O)8Si8O12 (3a) was determined by X‐ray crystallography for the first time. The developed procedures are the first, which allowed selective hydrosilylation of terminal silyl, germyl, aryl and alkyl alkynes with 1a, as well as the direct introduction of sixteen functional groups into the 1a structure by the hydrosilylation of internal alkynes. This method constituted a powerful tool for the synthesis of hyperbranched compounds with a Si‐O based cubic core. The resulting products, due to their unique structure and physicochemical properties, are considered novel, multifunctional, hybrid and nanometric building blocks, intended for the synthesis of star‐shaped molecules or macromolecules, as well as nanofillers and polymer modifiers. In the presented syntheses, commercially available reagents and catalysts were used, so these methods can be easily repeated, rapidly scaled up and widely applied.