Synthesis of Monofunctionalized Silsesquioxanes (RSiMe₂O)(iBu)₇Si₈O₁₂via Alkene Hydrosilylation

Abstract

The research presented in this work comprehensively describes hydrosilylation of a wide spectrum of alkenes which contain one or more reactive groups with (HSiMe O)(iBu) Si O , in the presence of different types of catalysts. Special attention is paid to the influence of alkene, catalyst, and reaction conditions on process effectiveness and selectivity by the precise monitoring of the experiments with in situ FTIR and NMR spectroscopies. More than twenty silsesquioxanes bearing reactive groups (OH, Br, NR , CO, COOR, NCO, epoxy, SiR ) commonly used in organic and polymer chemistry, were obtained, isolated and characterized by H, C, Si NMR and MALDI TOF. Importantly, in the presented syntheses, commercially available reagents and catalysts were used, meaning that the presented methods could be easily repeated, rapidly scaled up, and widely applied.

Highly Efficient Route for the Synthesis of a Novel Generation of Tetraorganofunctional Double‐decker Type of Silsesquioxanes

“…In obtained styryl derivatives of DDSQ-based system (3 i-k) we suspect statistical distribution of β-(n) and α-(m) substituted fragments in its one molecule rather than formation of two separate molecules of isomeric compounds with all four βand all four αsubstituted moieties (but it should not be omitted). [33,46] Herein, for all applied alkenes except for styrenes, a selective formation of β-hydrosilylation product was noted. Recent studies on the HS of olefins with (HSiMe 2 O)(iBu) 7 Si 8 O 12 have shown high selectivity for Karstedt's catalyst allowing formation of β-hydrosilylation product with high predominance.…”

“…However, this À OMe 2 SiÀ H moiety is attached to the T order of Si in 1-DDSQ and Q in (HSiMe 2 O)(iBu) 7 Si 8 O 12 [33] which may affect its reactivity in both cases. There is a resemblance of functional À OMe 2 SiÀ H group in 1-DDSQ and (HSiMe 2 O)(iBu) 7 Si 8 O 12 , i. e. M order of silicon atom.…”

“…[33] The reactions proceeded longer, i. e. approx. As it was mentioned, we observed similar selectivities of β-hydrosilylation products when styrenes were used, analogously to monosubstituted silsesquioxanes and regardless of the catalyst used.…”

“…At the same time, chemists are looking for synthetic routes exploiting among others hydrosilylation reaction to obtain novel, functionalized Si-based reagents with a specific structure such as silsesquioxanes. [17][18][19][20][21][22][23][24][25][26][27] While hydrosilylation of olefins with silanes has been widely studied, [3,28] the reports on T 8 silsesquioxanes are limited [5,6,[29][30][31][32][33][34] and for double-decker systems of both closed (D 2 T 8 [4,19,25,[35][36][37] ) and opened (M 4 T 8 [38][39][40][41][42][43] ) structure even more scant. [5] Cage-like derivatives have driven much attention due to specific physicochemical properties (governed by the nature of their silicate rigid core and by the number and type of functional groups attached to it) affecting directions of their broad applications from material chemistry to medicine.…”

“…[12,15,16] Taking research in the field of macromolecular DDSQ-based frameworks of hybrid nature into account, difunctionalized doubledecker silsesquioxanes are of greatest interest due to the possibility of their incorporation into the main chain of the polymer. [17][18][19][20][21][22][23][24][25][26][27] While hydrosilylation of olefins with silanes has been widely studied, [3,28] the reports on T 8 silsesquioxanes are limited [5,6,[29][30][31][32][33][34] and for double-decker systems of both closed (D 2 T 8 [4,19,25,[35][36][37] ) and opened (M 4 T 8 [38][39][40][41][42][43] ) structure even more scant. Miyashita and co-workers were the first to apply hydrosilylation as a method to modify tetrahydrosubstituted DDSQ (DDSQ-4OSiH) compound with N-vinylcarbazole performed in the presence of Karstedt's catalyst.…”