Ru-Catalyzed Dehydrogenative Silylation of POSS-Silanols with Hydrosilanes: Its Introduction to One-Pot Synthesis

Reduction of N2O with hydrosilanes catalysed by RuSNS nanoparticles

A series of RuSNS nanoparticles, prepared by decomposition of Ru(COD)(COT) with H₂ in the presence of an SNS ligand, have been found to catalyse the reduction of the greenhouse gas N₂O to N₂ employing different hydrosilanes.

Cobalt-Catalyzed Dehydrogenative C-H Silylation of Alkynylsilanes

Herein, we report that a cobalt catalyst permits the general synthesis of substituted alkynylsilanes through dehydrogenative coupling of alkynylsilanes and hydrosilanes. Several silylated alkynes, including di- and trisubstituted ones, were prepared in a one-step procedure. Thirty-seven compounds were synthesized for the first time by applying our catalyst system. The alkynylsilanes bearing hydrosilyl moieties provide an opportunity for further functionalization (e. g., hydrosilylation). The use of primary silanes as substrates and precatalyst activators permits the use of inexpensive and easily accessible 3d metal precatalysts, and avoids the presence of additional activators.

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

A methodology for synthesizing a wide range of dumbbell-shaped, graft and bottlebrush polymers with all-siloxane nature (without carbosilane linkers) is suggested. These macroarchitectures are synthesized from SiOH-containing compounds-silanol (Et₃ SiOH) and siloxanol dendrons of the first and second generations, with various peripheral substituents (Me or Et)-and from linear siloxanes comprising terminal and internal SiH groups by the Piers-Rubinsztajn reaction. Products and key building blocks are obtained in yields up to 95%. These polymers are heat and frost-resistant siloxanes. As it turns out, the product physical properties are determined not only by the macromolecular structure, the linear chain length, the size and frequency of branched pendant, but also by the type of peripheral substituents-Me or Et-in the pendant. Thus, the viscosity of the graft polymers with branched pendant groups comprising peripheral Me-groups is more than ≈3-5 fold lower than that of analogous polymers with peripheral Et-groups.

Janus ring siloxane: a versatile precursor of the extended Janus ring and tricyclic laddersiloxanes

All-cis-tetrasiloxycyclotetrasiloxanes (Janus ring siloxanes) were facilely prepared from all-cis-cyclotetrasiloxanetetraol or sodium cyclotetrasiloxane silanolates. Moreover, we demonstrated the synthesis of extended Janus rings, [RSi(OR')O]4, containing various functional groups, via the Piers-Rubinsztajn reaction using a Janus ring siloxane as a precursor. Remarkably, we discovered the formation of an unexpected all-cis tricyclic laddersiloxane as a by-product. These synthesized compounds can be potential monomers of well-defined cage silsesquioxanes, Janus-type nanomaterials, and porous materials.

B(C6F5)3-Catalyzed Dehydrocoupling of POSS Silanols with Hydrosilanes: A Metal-Free Strategy for Effecting Functionalization of Silsesquioxanes

We report a highly effective metal-free catalytic procedure for the functionalization of silsesquioxanes via dehydrocoupling of various POSS silanols with hydrosilanes in the presence of commercially available tris(pentafluorophenyl)borane B(C₆F₅)₃. This approach enables the unprecedented one-pot synthesis of valuable silsesquioxane derivatives under mild conditions, with no corrosive byproducts formed in the process.

Silylation of silanols with hydrosilanes via main-group catalysis: the synthesis of unsymmetrical siloxanes and hydrosiloxanes

Apart from some specific synthetic solutions, a dehydrogenative coupling of silanols with hydrosilanes seems to be the most atom-economical and practical method for the formation of unsymmetrical siloxanes.

Half-sandwich ruthenium(ii) complexes with tethered arene-phosphinite ligands: synthesis, structure and application in catalytic cross dehydrogenative coupling reactions of silanes and alcohols

The preparation of the tethered arene-ruthenium(ii) complexes [RuCl₂{η⁶:κ¹(P)-C₆H₅(CH₂)_nOPR₂}] (R = Ph, n = 1 (9a), 2 (9b), 3 (9c); R = ⁱPr, n = 1 (10a), 2 (10b), 3 (10c)) from the corresponding phosphinite ligands R₂PO(CH₂)_nPh (R = Ph, n = 1 (1a), 2 (1b), 3 (1c); R = ⁱPr, n = 1 (2a), 2 (2b), 3 (2c)) is presented. Thus, in a first step, the treatment at room temperature of tetrahydrofuran solutions of dimers [{RuCl(μ-Cl)(η⁶-arene)}₂] (arene = p-cymene (3), benzene (4)) with 1-2a-c led to the clean formation of the corresponding mononuclear derivatives [RuCl₂(η⁶-p-cymene){R₂PO(CH₂)_nPh}] (5-6a-c) and [RuCl₂(η⁶-benzene){R₂PO(CH₂)_nPh}] (7-8a-c), which were isolated in 66-99% yield. The subsequent heating of 1,2-dichloroethane solutions of these compounds at 120 °C allowed the exchange of the coordinated arene. The substitution process proceeded faster with the benzene derivatives 7-8a-c, from which complexes 9-10a-c were generated in 61-82% yield after 0.5-10 h of heating. The molecular structures of [RuCl₂(η⁶-p-cymene){ⁱPr₂PO(CH₂)₃Ph}] (6c) and [RuCl₂{η⁶:κ¹(P)-C₆H₅(CH₂)_nOPⁱPr₂}] (n = 1 (10a), 2 (10b), 3 (10c)) were unequivocally confirmed by X-ray diffraction methods. In addition, complexes [RuCl₂{η⁶:κ¹(P)-C₆H₅(CH₂)_nOPR₂}] (9-10a-c) proved to be active catalysts for the dehydrogenative coupling of hydrosilanes and alcohols under mild conditions (r.t.). The best results were obtained with [RuCl₂{η⁶:κ¹(P)-C₆H₅(CH₂)₃OPⁱPr₂}] (10c), which reached TOF and TON values up to 117 600 h^-1 and 57 000, respectively.

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

A simple and highly practical catalyst-free O-silylation of silanols with commercially available disilazanes has been developed under mild conditions. In the case of polyhedral oligomeric silsesquioxane (POSS) silanols and some other silanols, it was necessary to use catalytic amounts of inexpensive Bi(OTf)₃ as additional catalyst. This efficient chlorine-free protocol involves the synthesis of a wide range of important organosilicon derivatives such as unsymmetrical disiloxanes and functionalized silsesquioxanes.

Copper(ii) triflate-mediated synthesis of functionalized silsesquioxanes via dehydrogenative coupling of POSS silanols with hydrosilanes

In light of the fact that the design of new catalytic routes leading to functionalized silsesquioxanes is currently of high relevance; herein we report a novel, highly effective and convenient catalytic approach for the modification of silsesquioxanes. We present a dehydrogenative coupling reaction of completely as well as incompletely condensed POSS silanols with a wide range of commercially available hydrosilanes mediated by inexpensive copper(ii) trifluoromethanesulfonate. This research also includes mechanistic studies for this process.