A highly selective synthesis of new alkenylsilsesquioxanes by hydrosilylation of alkynes

Abstract

Hydrosilylation of a wide group of mono- and disubstituted (symmetrical and nonsymmetrical) alkynes with 1-dimethylsiloxy-3,5,7,9,11,13,15-heptaisobutylpentacyclo-[9.5.1.1.1.1]octasiloxane ((HSiMeO)(i-Bu)SiO, 1) in the presence of Karstedt's catalyst (Pt(dvs)) has been performed for the first time. A series of new 1,2-(E)-disubstituted and 1,1,2-(E)-trisubstituted ethenes with a silsesquioxane moiety were selectively afforded and fully characterized. On the basis of nuclear magnetic resonance (NMR) and infrared spectroscopy (in situ FT-IR and/or FT-IR), the influence of alkyne structure and reaction conditions on the stereoselectivity as well as on the progress of triple bond hydrosilylation catalyzed by Pt(dvs) was explained. The results of the studies clearly indicated for which reagents the developed procedures lead to alkenylsilsesquioxanes with almost stoichiometric yields in short time, and for which other catalytic systems or methods should be considered.

Regioselective formation of β‐(E)‐ and α‐alkenylsilane moiety attached to silsesquioxane core via Pt‐ and Ru‐based hydrosilylation

“…However, for HSiMe 2 OSiMe 3 and HSiMe 2 Ph, DCM can be used as alternative solvent. This Pt‐I system may be an optional method for the selective synthesis of the desired β‐( E )‐ 3 , when compared with the results obtained for HS of ethynylsilane with (iBu) 7 POSS‐OMe 2 Si‐H . Here, the reaction conditions are milder than those for the reverse functional group combinations.…”

“…With regard to the literature on silsesquioxanes bearing one or eight functional SiH group(s), reports on their use in HS are limited . Likewise, silsesquioxanes with alkynyl/ethynyl moieties in proximity to the POSS core are rarely found and it is probably for this reason that there are no reports of their reactivity in HS reactions …”

Introduction of Boron Functionalities into Silsesquioxanes: Novel Independent Methodologies

“…[9][10][11][12] Recently,t he synthesis of functionalizeds ilsesquioxanes cages( SQs) containing other heteroatomsa nd functional groupsh as been strongly developed by many scientists. [23][24][25][26][27][28] On the other hand, the boron modification of variousc ompounds, [29][30][31][32][33] polymers, [34,35] and nanoparticles is attractivef or aw ide range of applications. [23][24][25][26][27][28] On the other hand, the boron modification of variousc ompounds, [29][30][31][32][33] polymers, [34,35] and nanoparticles is attractivef or aw ide range of applications.…”

“…[13][14][15][16][17] Traditionally,c onventional methods using halo-compounds are used to modify their structure, [18][19][20][21][22] however catalytic solutionsa re becoming increasingly investigated. [23][24][25][26][27][28] On the other hand, the boron modification of variousc ompounds, [29][30][31][32][33] polymers, [34,35] and nanoparticles is attractivef or aw ide range of applications. [36][37][38] Si-O-B moiety,w hich is ac ore of poly(borasiloxane)s, is very interesting in terms of modernp olymer chemistry.…”

“…Recently, the synthesis of functionalized silsesquioxanes cages (SQs) containing other heteroatoms and functional groups has been strongly developed by many scientists . Traditionally, conventional methods using halo‐compounds are used to modify their structure, however catalytic solutions are becoming increasingly investigated . On the other hand, the boron modification of various compounds, polymers, and nanoparticles is attractive for a wide range of applications .…”