Catalytic Approach to Germanium-Functionalized Silsesquioxanes and Germasilsesquioxanes

Abstract

Silsesquioxanes have attracted considerable attention in recent years due to their unique hybrid structure and versatile properties. Herein, we report the first catalytic approach to the synthesis of completely and partially condensed germaniumfunctionalized silsesquioxanes as well as germasilsesquioxanes, mediated by scandium(III) triflate. We provide a solution for introducing germyl functionalities into various types of silsesquioxanes under mild conditions with excellent yields. This methodology turns out to be a highly efficient and selective synthesis route to obtaining novel germanium-containing silsesquioxanes. These new multielement POSS derivatives may have great potential for further applications as valuable multifunctional building blocks in material chemistry.

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

“…[3] The measurable importance and relevance of this catalytic process in the synthesis of organosilicon compounds is recorded by the rapid increase in the number of publications, monographs and patents on its use recorded annually. [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. These are a group of organosilicon compounds that feature cage-like structures combining an inorganic SiÀ OÀ Si core and organic substituents attached to the silicon atoms.…”

“…The both, the nature and amount of functional groups attached to rigid DDSQ core affects the directions of research development, i. e. molecular and macromolecular organosilicon DDSQ-based systems. [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.…”

A Highly Effective Route to Si−O−Si Moieties through O‐Silylation of Silanols and Polyhedral Oligomeric Silsesquioxane Silanols with Disilazanes

“…These include reactions of hydroxy-substituted derivatives with halo-and alkoxy-substitutedm olecules. [51][52][53][54][55] We also discovered av ery efficient anda tom-economical methodf or O-borylation and hydroboration. Most of these transformationsare also characterized by low chemoselectivity (the formation of unwanted symmetricald isiloxanes), harsh reaction conditions, and low yields.…”

Introduction of Boron Functionalities into Silsesquioxanes: Novel Independent Methodologies

“…[57][58][59][60][61][62] Whereas, as previously described, new synthetic pathways for the synthesis and functionalization of variousS Qs cages via Sc(OTf) 3 -Scheme1.Catalyst-free dehydrocoupling of silanols with boranes. [57][58][59][60][61][62] Whereas, as previously described, new synthetic pathways for the synthesis and functionalization of variousS Qs cages via Sc(OTf) 3 -Scheme1.Catalyst-free dehydrocoupling of silanols with boranes.…”

“…Kaźmierczak catalyzed coupling of SiÀOH groups in silsesquioxane molecules employed various2 -methylallylsilanes [60] and germanes (Scheme 2), [61] we decided to extendt his catalytic approach by also using allylborons pecies, which are commonly appliedi n many organic transformations. J.…”