Octasilsesquioxanes hydrosilylation

Neumann and coworkers [6] reported the first synthesis and characterization of a novel POSS, possessing eight isocyanate groups (XVIII) (Scheme 5) via the hydrosilylation of m-isopropenyl-Q ,Q -dimethylbenzyl isocyanate (m-TMI) (XVII) by octakis(dimethylsiloxy)octasilsesquioxane (Q8M8 ) (XVI). 

To sum up, octakis(3-hydroxypropyldimethylsiloxy)octasilsesquioxane (OHPS) has also been synthesized by direct hydrosilylation of allyl alcohol with octakis(dimethylsiloxy)octasilsesquioxane, (HSiMe20)8Si80i2... 

Summary Starting with octa(vinyldimethylsiloxy)octasilsesquioxane (QsMs ) as the central core molecule, allyl- and chloro-substituted dendritic macromolecules have been prepared by the divergent route. The sequence of hydrosilylation with dichloro-methylsilane followed by allylation of all Si-Cl groups with CH2=CHCH2MgBr, was used for building up each generation (G1-G4). We also functionalized the dendrimer periphery via hydrosilylation reaction of allyl-functionalized dendrimers with dimethylsilylferrocene. These novel molecules have been characterized by H/ C/ Si-NMR, IR spectroscopy and MALDl-TOF spectrometry. The ferrocenyl-substituted molecules have also been analyzed by cyclovoltammetry. 

In our strategy for the synthesis of carbosilane dendrimers, hydrosilylation and allylation reaction sequences were chosen starting with octa(vinyldimethylsiloxy)octasilsesquioxane (Q lVIg ) as core molecule (Scheme 1). 

As a first step in realizing dendrimers with terminal allyl and chloro groups we prepared the first-generation octa[2-(dichloromethylsilylethyl)dimethylsiloxy]octasilsesquioxane (Gl-CI) via Pt-catalyzed hydrosilylation of the core molecule with dichloromethylsilane. Then each... 

Synthesis of heptaisobutyl[11-hydroxyundecenyl]octasilsesquioxane via hydrosilylation of monohydridoheptaisobutylsilsesquioxane with 10-undecenol 152... 

Synthesis of Itetrakislf 1,1,2,2,3,3,4,4-octafluoropentyloxypropyl dimethylsiloxy)) tetrakis 3-glycidoxypropyl dimethylsiloxy)octasilsesquioxane via hydrosilylation of allyl-glycidyl ether and 1,1,2,2,3,3,4,4-octafluoropentyl allyl ether with octakis(hydridodimethylsiloxy)octasilsesquioxane 153... 

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