Synthesis of structured polysiloxazanes via a Piers–Rubinsztajn reaction

Abstract

The first example of the Piers–Rubinsztajn reaction in the synthesis of molecules containing Si–O–Si–N bonds.

Hyperbranched Polycarbosiloxanes: Synthesis by Piers-Rubinsztajn Reaction and Application as Precursors to Magnetoceramics

“…In particular, developing Si-HBPs via simple, rapid and mild synthetic procedures is highly desirable. The Piers-Rubinsztajn (P-R) reaction, namely the condensation of alkoxysilanes with hydrosilanes, has rapidly developed since it was found in the 1990s [22,23], because this strategy is mild and provides a possibility for the controlled or precise synthesis of silicones, including small molecules, linear polymers, and crosslinked materials [24][25][26][27][28][29][30][31]. For example, the P-R coupling reactions of various organic tris(dimethylsiloxy)silane and trialkoxysilane compounds can generate a series of cyclic polysiloxanes with cyclotetrasiloxane subunits in a simple one-step synthesis [32].…”

Dumbbell‐Shaped, Graft and Bottlebrush Polymers with All‐Siloxane Nature: Synthetic Methodology, Thermal, and Rheological Behavior

“…It is also worth noting that the synthesizing of well‐defined siloxane (macro)structures with SiO R groups ( R = H, Me, Et) as the building blocks is a challenge in organosilicon chemistry; at the same time, they are “greener” reagents than chlorosilanes, silazanes, etc. [ 44–57 ]…”

“…[44,45] Thus, a few main types of processes for synthesizing (macro) structures with a SiOSi group can be distinguished: [44,45] 1) polycondensation of chloro-and alkoxysilanes; 2) metathesis (or redistribution) of (cyclo)siloxanes; 3) condensation of silanols or silanolates with chlorosilanes; 4) processes based on the Piers-Rubinsztajn reaction, that is, reactions of hydride silanes with alkoxysilanes or silanols. [46][47][48][49][50][51][52][53][54][55] As a rule, the processes belonging to groups (1) and 2are not applicable for synthesizing individual siloxanes or polysiloxanes with a required structure as they give equilibrium mixtures of cyclic, linear, and branched products with different molecular weights, depending on the structure of the starting compounds and reaction conditions. The processes of groups 3and 4are more applicable for the controlled synthesis of siloxanes with well-defined structures.…”

“…It is also worth noting that the synthesizing of well-defined siloxane (macro)structures with SiOR groups (R = H, Me, Et) as the building blocks is a challenge in organosilicon chemistry; at the same time, they are "greener" reagents than chlorosilanes, silazanes, etc. [44][45][46][47][48][49][50][51][52][53][54][55][56][57] To summarize the above, the development of a methodology for the synthesis of both well-defined all-siloxane branched building blocks and macrostructures based on them with an all-siloxane backbone (without a hydrocarbon or carbosilane moiety in the macromolecule skeleton) is a complex synthetic problem. However, this approach is promising and much-indemand.…”

Catalytic Synthesis of Oligosiloxanes Mediated by an Air Stable Catalyst, (C6F5)3B(OH2)

“…Main group (and metal-free) catalysts such as B(C 6 F 5 ) 3 have gained great interest as a catalyst activator and as strong Lewis acid for many purposes (Piers, 2004;Lawson and Melen, 2017;Brook, 2018). Several studies have been published for the preparation of siloxanes and hyperbranched siloxanes involving catalytic cross-coupling reactions of oxygen nucleophiles (e.g., alkoxysilanes, silanols, phenols, and ethers) with hydrosilanes (Kawakami et al, 2004;Chojnowski et al, 2005Chojnowski et al, , 2006Chojnowski et al, , 2008Zhou and Kawakami, 2005;Shinke et al, 2007;Thompson and Davies, 2007;Cella and Rubinsztajn, 2008;Kurjata et al, 2009;Feghali and Cantat, 2014;Madsen et al, 2014;Zhang et al, 2014Zhang et al, , 2020Feghali et al, 2015;Laengert et al, 2017;Szawiola et al, 2017;Wu et al, 2017;Brook, 2018;Ai et al, 2019). Recently, Matsumoto and co-workers reported a sequencecontrolled synthesis of oligosiloxanes via dehydrocarbonative coupling of alkoxysilanes and hydrosilanes, named the Piers-Rubinsztajn reaction, and also via hydrosilylation of carbonyl compounds using B(C 6 F 5 ) 3 (Matsumoto et al, 2018).…”