Selective Boryl Silyl Ether Formation in the Photoreaction of Bisboryloxide/Boroxine with Hydrosilane Catalyzed by a Transition-Metal Carbonyl Complex

Widening the Landscape of Small Molecule Activation with Gold-Aluminyl Complexes: A Systematic Study of E-H (E=O, N) Bonds, SO2 and N2 O Activation

The electronic features of gold-aluminyl complexes have been thoroughly explored. Their similarity with Group 14 dimetallenes and other metal-aluminyl complexes suggests that their reactivity with small molecules beyond carbon dioxide could be accessed. In this work, the reactivity of the [^t Bu₃ PAuAl(NON)] (NON=4,5-bis(2,6 diisopropylanilido)-2,7-ditert-butyl-9,9-dimethylxanthene) complex towards water, ammonia, sulfur dioxide and nitrous oxide is computationally explored. The reaction mechanisms computed for each substrate strongly suggest that all activation processes are in principle experimentally feasible. Electronic structure analysis highlights that, in all cases, the reactivity is driven by the presence of the poorly polarized electron-sharing gold-aluminyl bond, which induces a radical-like reactivity of the complex towards all the substrates. A flat topology of the potential energy surface (PES) has been found for the reaction with N₂ O, where two almost isoenergetic transition states can be located along the same reaction coordinate with different geometries, suggesting that the N₂ O binding mode may not be a good indicator of the nature of N₂ O activation in a cooperative bimetallic reactivity. In addition, the catalytic potentialities of these complexes have been explored in the framework of nitrous oxide reduction. The study reveals that the [^t Bu₃ PAuAl(NON)] complex might be an efficient catalyst towards oxidation of phosphines (and boranes) via N₂ O reduction. These findings underline recurring trends in the novel chemistry of gold-aluminyl complexes and call for experimental feedbacks.

Polyborosiloxanes (PBS): Evolution of Approaches to the Synthesis and the Prospects of Their Application

The mini-review deals with borosiloxanes as a class of organoelement compounds that comprise Si-O-B bonds, including individual compounds and polymeric structures. The borosiloxanes first synthesized in the 1950s using simple methods demonstrated very unusual properties but were hydrolytically unstable. However, in recent times, synthetic methods have changed significantly, which made it possible to synthesize borosiloxanes that are resistant to external factors, including atmospheric moisture. Borosiloxanes became important due to their unique properties. For example, borosiloxane liquids acquire a thixotropic behavior due to donor-acceptor interchain interactions. In addition, borosiloxanes are used to produce flame-retardant ceramics. An analysis of the literature sources shows that no review has yet been completed on the topic of borosiloxanes. Therefore, we decided that even a brief outlook of this area would be useful for researchers in this and related fields. Thus, the review shows the evolution of the synthesis methods and covers the studies on the properties of these unique molecules, the latest achievements in this field, and the prospects for their application.

Deoxygenation of Nitrous Oxide and Nitro Compounds Using Bis(N-Heterocyclic Silylene)Amido Iron Complexes as Catalysts

Herein, we report the efficient degradation of N₂ O with a well-defined bis(silylene)amido iron complex as catalyst. The deoxygenation of N₂ O using the iron silanone complex 4 as a catalyst and pinacolborane (HBpin) as a sacrificial reagent proceeds smoothly at 50 °C to form N₂ , H₂ , and (pinB)₂ O. Mechanistic studies suggest that the iron-silicon cooperativity is the key to this catalytic transformation, which involves N₂ O activation, H atom transfer, H₂ release and oxygenation of the boron sites. This approach has been further developed to enable catalytic reductions of nitro compounds, producing amino-boranes with good functional-group tolerance and excellent chemoselectivity.

A catalyst- and additive-free synthesis of alkoxyhydrosiloxanes from silanols and alkoxyhydrosilanes

A convenient method for the selective synthesis of alkoxyhydrosiloxanes that bear SiH and SiOR² groups on the same silicon atom, R¹₃Si-O-SiR³_2-n(OR²)_nH (n = 0, 1, or 2), via a simple catalyst- and additive-free dealcoholization reaction between silanols and alkoxyhydrosilanes has been developed. These alkoxyhydrosiloxanes can be easily converted into Si(OR²)₃-containing siloxanes by zinc catalyzed alkoxylation and alkoxy-containing silphenylene polymers by platinum catalyzed hydrosilylation.

Introduction of Boron Functionalities into Silsesquioxanes: Novel Independent Methodologies

Owing to their versatile application possibilities, silsesquioxanes (SQs) are of considerable interest for creating hybrid inorganic-organic materials. In this report, two novel and independent strategies for the direct attachment of boron functionalities to silsesquioxanes are presented. Encouraged by our previous work concerning the synthesis of borasiloxanes through the catalyst-free dehydrogenative coupling of silanols and boranes, we decided to apply our method to a synthesis of various boron-functionalized silsesquioxanes. During our tests, we also investigated the activity of scandium(III) triflate, which we have previously used as an excellent catalyst for the obtaining of Si-O-Si and Si-O-Ge moieties. As a result, we also discovered a novel approach for the O-borylation of Si-OH groups in silsesquioxanes with allylborane. Both routes are highly chemoselective and efficiently lead to the obtaining of Si-O-B moiety under air atmosphere and at room temperature.

Chemoselective and Catalyst-Free O-Borylation of Silanols: A Facile Access to Borasiloxanes

This paper demonstrates the first highly chemoselective syntheses of various borasiloxanes from hydroboranes and silanols, achieved through catalyst-free dehydrogenative coupling at room temperature. This green protocol, which uses easily accessible reagents, allows for the obtaining of borasiloxanes under air atmosphere and solvent-free conditions.

Synthesis of borasiloxanes by oxidative hydrolysis of silanes and pinacolborane using Cu3(BTC)2 as a solid catalyst

This work reports the synthesis of borasiloxanes from silanes and pinacolboranes using Cu₃(BTC)₂ as a heterogeneous catalyst in acetonitrile under mild conditions.

Ruthenium-catalysed multicomponent synthesis of borasiloxanes

Ruthenium-catalysed multicomponent synthesis of borasiloxanes directly from silanes, boranes and water is reported.

A convenient and clean synthetic method for borasiloxanes by Pd-catalysed reaction of silanols with diborons

Pd-Catalysed O-borylation of silanols with diborons selectively proceeded to give the corresponding boryl silyl ethers in high yields.

C4-Ferrocenylsilyl-bridged and -substituted N-heterocyclic carbenes: complexation of germanium chloride

C4-Ferrocenylsilyl-bridged and -substituted N-heterocyclic carbenes and their germanium chloride complexes have been prepared and characterized.

From Stiba- and Bismaheteroboroxines to N,C,N-Chelated Diorganoantimony(III) and Bismuth(III) Cations-An Unexpected Case of Aryl Group Migration

An unprecedented transfer of an aryl group from boron to Sb and Bi is observed in the reaction of heteroboroxines of general formula ArM[(OBR)2O] [where M = Sb, Bi; Ar = C6H3-2,6-(CH2NMe2)2; R = Ph, 4-CF3C6H4, 4-BrC6H4] with corresponding boronic acid RB(OH)2. Using this procedure, ion pairs [ArMR](+)[R4B5O6](-) were obtained [where M = Sb and R = Ph (4), 4-CF3C6H4 (5), 4-BrC6H4 (6); where M = Bi and R = Ph (7), 4-CF3C6H4 (8), 4-BrC6H4 (9)]. All compounds were characterized using elemental analysis, electrospray ionization mass spectrometry, and multinuclear NMR spectroscopy, and molecular structures of 4 and 7 were determined by single-crystal X-ray diffraction analysis. The central metal atoms in 4-9 were arylated by respective boronic acids, which represents, to the best of our knowledge, unprecedented reaction path in the chemistry of heavier group 15 elements. Investigation of the mechanism of this transformation indicated that Lewis pairs consisting of monomeric oxides ArMO and boroxine rings are probably key intermediates. In this regard, molecular structures of ArSbO[(4-CF3C6H4)3B3O3]·(4-CF3C6H4)B(OH)2 (10) and {ArSbO[(3,5-(CF3)2C6H3)3B3O3]} (13) were established by single-crystal X-ray diffraction analysis, and compound 13 was also fully characterized in solution by multinuclear NMR spectroscopy. The bonding in 13 was analyzed in detail by using density functional theory and natural bond order calculations and compared with known adduct ArSbOB(C6F5)3 (14) and hypothetical ArSbO monomer.