A new catalytic approach to germasiloxanes

Introduction of Boron Functionalities into Silsesquioxanes: Novel Independent Methodologies

“…Furthermore, encouraged by the successful use of Sc(OTf) 3 in the O-metalationo fc ompounds containing SiÀOH groups, [57][58][59][60][61] it was decided to extend this methodology and investigate the activity of scandium(III) triflate as the catalyst in the coupling reactionb etween silanols and 2-methylallylborane. In this research, the focusw as primarily on the introduction of boron functionalities into the structures of silsesquioxanes.…”

“…At the same time, the research team has recentlyp laced a strong focus on the use of metal triflates as catalysts in O-silylation,a sw ell as S-a nd O-germylationr eactions. [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 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. [63,64] In this paper,t wo independent strategiesa re described for the construction of boron-functionalized silsesquioxanes ( Figure 1).…”

Ru0‐Catalyzed Coupling of Vinylboronates with Silanols, Disilanols, and Disiloxanediols: a Selective Route to Borasiloxanes

“…The activity of Ru(COD)(COT) in the coupling reaction was lower than that of Ru 3 (CO) 12 . Our recent studies recognized Ru 3 (CO) 12 as an effective and selective catalyst in the O ‐germylation of silanols and proved that it has virtually no activity towards the homocoupling of vinylmetalloids (see ref 13…”

“…The results from our previous report on the reaction of silanols with vinylgermanes, which is catalyzed selectively by the complex Ru 3 CO 12 ,13 prompted us to make use of this general feature of Ru 0 complexes (lack of activity in the homocoupling of vinylmetalloids) in the O ‐metallation of silanols, silanediols, and siloxanediols by vinylboronates. Moreover, we wanted to extend the scope of substrates for the O ‐borylation reaction with dihydroxysilicon derivatives, such as silanediols and siloxanediols.…”

A new selective approach to unsymmetrical siloxanes and germasiloxanes via O-metalation of silanols with 2-methylallylsilanes and 2-methylallylgermanes

“…6 During the course of our recent studies on the catalytic activation of O-H bonds of silanols and alcohols by vinylmetalloids we have developed new catalytic routes for efficient O-silylation of silanols with vinylsilanes catalyzed by [RuHCl(CO)(PCy 3 ) 2 ] 7 and O-germylation of silanols with vinylgermanes catalyzed by [Ru 3 (CO) 12 ]. 8 Recently we have focused our research on the use of 2-methylallylsilanes and 2-methylallylgermanes as metalating agents and hydrogen acceptors for the O-metalation of silanols to form disiloxane or germasiloxane bonds, respectively.…”