Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

Abstract

A novel synthetic method for the construction of a double-decker silsesquioxane from fluorosilanes was developed. Phenyl-substituted double-decker silsesquioxane was prepared under mild conditions by coupling difluorodiphenylsilane and a tetrasiloxanolate precursor. A similar reaction was performed using difluorovinylsilane, and a divinyl double-decker silsesquioxane was obtained. The one-step reaction of a functional difluorosilane containing an aminopropyl group afforded a novel double-decker silsesquioxane with two amino groups complexed with BF3, which can react with carboxylic acid anhydrides to afford an amide product. This synthetic method using difluorosilane is tolerant of a wide range of functional groups and is applicable to the synthesis of polycyclic silsesquioxanes bearing amino groups, which are difficult to directly obtain from dichlorosilane.

Silylation of Alcohols, Phenols, and Silanols with Alkynylsilanes – an Efficient Route to Silyl Ethers and Unsymmetrical Siloxanes

“…unique physical and chemical properties are widely used in material science. [43,44] Also this time (the Si-O-Si bond formation), there are several established methods, which can be carried out in both stoichiometric [43,45,46] or catalytic manner. [47][48][49][50][51][52][53][54][55][56][57][58][59][60] To sum up, the vast majority of known O-silylation strategies is presented on Figure 1, including their main benefits and drawbacks.…”

Progress in the Synthesis of Bifunctionalized Polyhedral Oligomeric Silsesquioxane

“…The temperature of 5 wt % weight loss (T5%) and the char residue yield at 800 °C suggested good flame retardancy of PC/ABS containing B-POSS. With a special substituted difluorosilane as a precursor, Tanaka et al [100] reported a substituted difluorosilane prepared from the reaction between BF3•Et2O and siloxanolate in the synthesis of an amide product. The difluorosilane, bearing a vinyl-or BF3-complexed amino group, was used as the raw material to synthesize polycyclic silsesquioxanes under mild conditions.…”

“…Due to the simplicity of materials processing, good solubility, high chain regularity, and POSS content in the hybrids [89,105], more attention has been paid to B-POSS-containing linear composite materials because of the specific nanostructure, hydrophobic core, functionalization, flame retardance, optical transparency, and low thermal conductivity. With a special substituted difluorosilane as a precursor, Tanaka et al [100] reported a substituted difluorosilane prepared from the reaction between BF 3 •Et 2 O and siloxanolate in the synthesis of an amide product. The difluorosilane, bearing a vinyl-or BF 3 -complexed amino group, was used as the raw material to synthesize polycyclic silsesquioxanes under mild conditions.…”

Phase Behavior of Selected Condensed Double-Decker Shaped Silsesquioxane Compounds

“…Reacting tetrasilanol of double-decker shaped octaphenyl silsesquioxane DDSQ(OH) 4 with an appropriate quantity of dichlorosilanes (RR'SiCl 2 ) or difluorosilanes (RR'SiF 2 ) can result in a fully condensed structure (DDSQ-2(RR')) as observed in Scheme 1 [1][2][3][4][5][6][7][8][9]. These compounds have been used to form hybrid polymers with silsesquioxane as a part of the backbone [3,6,10].…”