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The reactivity of the phosphanyl‐phosphagallene, [H2C{N(Dipp)}]2PP=Ga(Nacnac) (Nacnac=HC[C(Me)N(Dipp)]2; Dipp=2,6‐ i Pr2C6H3) towards a series of reagents possessing E−H bonds (primary amines, ammonia, water, phenylacetylene, phenylphosphine, and phenylsilane) is reported. Two contrasting reaction pathways are observed, determined by the polarity of the E−H bonds of the substrates. In the case of protic reagents (δ−E−Hδ+), a frustrated Lewis pair type of mechanism is operational at room temperature, in which the gallium metal centre acts as a Lewis acid and the pendant phosphanyl moiety deprotonates the substrates. Interestingly, at elevated temperatures both NH2 i Pr and ammonia can react via a second, higher energy, pathway resulting in the hydroamination of the Ga=P bond. By contrast, with hydridic reagents (δ+E−Hδ−), such as phenylsilane, hydroelementation of the Ga=P bond is exclusively observed, in line with the polarisation of the Si−H and Ga=P bonds., We describe the synthesis and reactivity of a phosphanyl phosphagallene towards reagents with protic and hydridic E−H bonds. These studies reveal that there are two competing reactivity pathways available for such bond activation reactions: a frustrated Lewis pair type of mechanism, and a competing pathway which results in the hydroelementation of the Ga=P double bond.

In recent years, the applications of low-valent main group compounds have gained momentum in the field of catalysis. Owing to the accessibility of two lone pairs of electrons, NHC-stabilised phosphinidenes have been found to be excellent Lewis bases; however, they cannot yet be used as catalysts. Herein, an NHC-stabilised phosphinidene, 1,3-dimethyl-2-(phenylphosphanylidene)-2,3-dihydro-1H imidazole (1), for the activation of CO2 is reported.A closer inspection of the CO2 activation process by DFT calculations along with intrinsic bond orbital analysis shows that phosphinidene is associated with phenylsilane through a noncovalent π-π interaction between two phenyl rings which activates the Si-H bond facilitating hydride transfer to the CO2 molecule. Detailed DFT studies along with spectroscopic experiments were combined to understand the mechanism of CO2 activation and its catalytic reductive functionalisation leading to the formylation of a range of chemically inert primary amides under mild reaction conditions.

Herein, we describe a convenient and general method for the oxidation of olefins to ketones using either tris(dibenzoylmethanato)iron(III) [Fe(dbm)3] or a combination of iron(II) chloride and neocuproine (2,9‐dimethyl‐1,10‐phenanthroline) as catalysts and phenylsilane (PhSiH3) as additive. All reactions proceed efficiently at room temperature using air as sole oxidant. This transformation has been applied to a variety of substrates, is operationally simple, proceeds under mild reaction conditions, and shows a high functional‐group tolerance. The ketones are formed smoothly in up to 97 % yield and with 100 % regioselectivity, while the corresponding alcohols were observed as by‐products. Labeling experiments showed that an incorporated hydrogen atom originates from the phenylsilane. The oxygen atom of the ketone as well as of the alcohol derives from the ambient atmosphere., Various iron catalyst systems featuring a range of different ligands have been evaluated for the Wacker‐type oxidation of olefins to ketones in the presence of phenylsilane at room temperature and ambient air. The transformation is operationally simple, sustainable, exhibits a high functional group tolerance, and is applicable to natural product synthesis.

The aluminyl anion K[Al(NONDipp)] {NONDipp = [O(SiMe2NDipp)2]2-; Dipp = 2,6-iPr2C6H3} engages in oxidative additions with the E-H (E = Si, P, N, or O) bonds of phenylsilane (PhSiH3), mesityl phosphane (MesPH2; Mes = 2,4,6-Me3C6H2), 2,6-di-iso-propylaniline (DippNH2), and 2,6-di-tert-butyl-4-methylphenol (ArOH). The resulting (hydrido)aluminate salts are formed regardless of the E-H bond polarity. All of the products were characterized by nuclear magnetic resonance and infrared spectroscopic techniques and single-crystal X-ray diffraction. This study highlights the versatility of aluminyl anions to activate hydridic, acidic, and (essentially) nonpolar E-H bonds.

An efficient method has been developed for the reductive amination of CO2 by using readily available and recyclable oxofluorovanadates as catalysts. Various amines are transformed into the desired N-formylated products in moderate to excellent yields at room temperature in the presence of phenylsilane. Mechanistic studies based on in situ infrared spectroscopy suggest a reaction pathway initiated through F-Si interactions. The activated phenylsilane allows for CO2 insertion to produce phenylsilyl formate, which undergoes attack by the amine to generate the target product.

Porous materials with heterogeneous nature occupy a pivotal position in the chemical industry. This work described a facile pre- and post-synthetic approach to modify porous hypercrosslinked polymer with quaternary ammonium bromide, rendering it as efficient catalyst for CO2 conversion. The as-prepared porous ionic polymer (PiP@QA) displayed an improved specific surface area of 301 m2·g−1 with hierarchically porous structure, good selective adsorption of CO2, as well as high ion density. Accordingly, PiP@QA catalyst exhibited excellent catalytic performances for the solvent-free synthesis of various formamides from CO2, amines and phenylsilane under 35 °C and 0.5 MPa. We speculated that the superior catalytic efficiency and broad substrate scope of this catalyst could be resulted from the synergistic effect of flexible ionic sites with unique nanoporous channel that might increase the collision probability of reactants and active sites as well as enhance the diffusion of reactants and products during the reaction process. With the good reusability, PiP@QA was also available for the efficient conversion of simulated flue gas (15% CO2 in N2, v/v) into target formamides with quantitative selectivity at room temperature, which further highlighted its industrial application potential in chemical recycling the real-word CO2 to valuable products.

The one-step C-methylenation of anilines and indoles with CO2 and phenylsilane was catalyzed by a pentanuclear ZnII complex to give diarylmethanes via geminal C–H and C–C bond formation. It is proposed that the zinc–hydride complex generated in situ is a catalytically active species and that bis(silyl)acetal is a key intermediate. When aniline was used as a substrate, both the C-methylenation and N-methylation proceeded.

We propose a new direct anodic electrodeposition process for carbon coatings that is possible at room temperature in ionic liquid (IL) with phenylsilane derivatives, which include dimethylphenylsil...

A methodology employing CO2, amines, and phenylsilane was discussed to access aryl- or alkyl-substituted urea derivatives. This procedure was characterized by adopting hydrosilane to promote the formation of ureas directly, without the need to prepare silylamines in advance. Control reactions suggested that FeCl3 was a favorable additive for the generation of ureas, and this 1,5,7-triazabicyclo[4.4.0]dec-5-ene-catalyzed reaction might proceed through nucleophilic addition, silicon migration, and the subsequent formal substitution of silylcarbamate.

The dehydrocoupling of silanes and alcohols mediated by heavier alkaline-earth catalysts, [Ae{N(SiMe 3) 2} 2⋅(THF) 2] (I–III) and [Ae{CH(SiMe 3) 2} 2⋅(THF) 2], (IV–VI) (Ae=Ca, Sr, Ba) is described. Primary, secondary, and tertiary alcohols were coupled to phenylsilane or diphenylsilane, whereas tertiary silanes are less tolerant towards bulky substrates. Some control over reaction selectivity towards mono-, di-, or tri-substituted silylether products was achieved through alteration of reaction stoichiometry, conditions, and catalyst. The ferrocenyl silylether, FeCp(C 5H 4SiPh(OBn) 2) (2), was prepared and fully characterized from the ferrocenylsilane, FeCp(C 5H 4SiPhH 2) (1), and benzyl alcohol using barium catalysis. Stoichiometric experiments suggested a reaction manifold involving the formation of Ae–alkoxide and hydride species, and a series of dimeric Ae–alkoxides [(Ph 3CO)Ae(μ 2-OCPh 3)Ae(THF)] (3 a–c, Ae=Ca, Sr, Ba) were isolated and fully characterized. Mechanistic experiments suggested a complex reaction mechanism involving dimeric or polynuclear active species, whose kinetics are highly dependent on variables such as the identity and concentration of the precatalyst, silane, and alcohol. Turnover frequencies increase on descending Group 2 of the periodic table, with the barium precatalyst III displaying an apparent first-order dependence in both silane and alcohol, and an optimum catalyst loading of 3 mol % Ba, above which activity decreases. With precatalyst III in THF, ferrocene-containing poly- and oligosilylethers with ferrocene pendent to- (P1–P4) or as a constituent (P5, P6) of the main polymer chain were prepared from 1 or Fe(C 5H 4SiPhH 2) 2 (4) with diols 1,4-(HOCH 2) 2-(C 6H 4) and 1,4-(CH(CH 3)OH) 2-(C 6H 4), respectively. The resultant materials were characterized by NMR spectroscopy, gel permeation chromatography (GPC) and DOSY NMR spectroscopy, with estimated molecular weights in excess of 20,000 Da for P1 and P4. The iron centers display reversible redox behavior and thermal analysis showed P1 and P5 to be promising precursors to magnetic ceramic materials.

We report a safe and convenient method to prepare a new class of network polysilane, or polysilyne ([RSi]n). Simple thermolysis of a readily accessible linear poly(phenylsilane), [PhSiH]n, affords polysilyne [PhSi]n with concomitant evolution of monosilanes. This new polymer shows a hyperbranched structure with unique features not observed in known polysilynes prepared via hazardous Wurtz coupling routes. Despite these differences, our soluble, yellow polysilyne exhibits some important properties associated with the traditional random network structure: it absorbs up to 400 nm in the UV spectrum, yet is stable to photolysis under inert atmosphere. This efficient new synthetic route opens the door to exciting applications for these hyperbranched polymers in materials and device technologies.

Here we present the results of our DFT study of triethylborohydride-catalysed CC bond hydrosilylation reactions. On the basis of the investigation of the potential energy hypersurface at the M06-2X/6-31++G(d,p)//M06-2X/6-31+G(d) level of theory, we propose a detailed mechanism and energy profile for the reaction of styrene with phenylsilane and describe geometric and electronic structures of stationary points corresponding to each step. The model proposed is also applied to a number of other potential reagents, namely 1,1-diphenylethene, propene, dimethylphenylsilane, and trimethylsilane. The results of quantum-chemical computations not only provide a consistent explanation of the high regioselectivity of NaHBEt3-catalysed hydrosilylation, but are also in good agreement with the experimental yields depending on the substrates used, hence they not only further support the mechanism presented, but also make a computational toolkit for predicting reactivities.

Reactions of dichlorodimethylsilane with 2,3,4,5-tetrafluorophthalic acid bis(trimethylsilyl) ether (1:1, 20°C, 24 h) without a solvent and dichloro(chloromethyl)methylsilane and dichloro(methyl)phenylsilane with bis(trimethylsilyl) ester of ortho-phthalic acid (1:1, 20°C, 168–264 h) in hexane lead to the formation of previously unknown 14-membered cyclic organosilicon esters of ortho-phthalic acids (silacyclophanones) in 36–85% yields. Molecular structures of 14-membered cyclic ethers 4,10-dimethyl-4,10-diphenyl-3,5,9,11-tetraoxo-4,10-disyla-1,7(1,2)-dibenzacyclododecaphane-2,6,8,12-tetraone, 4,4,10,10-tetramethyl-3,5,9,11-tetraoxo-4,10-disila-1,7(1,2)-di-(tetrafluorobenza)cyclododecaphane-2,6,8,12-tetraone, along with bis(trimethylsilyl) esters of 2,3,4,5-tetrafluorophthalic and orthophthalic acids, were studied by X-ray structural analysis.

Abstract In this paper hydrophobization of cotton fabric with a range of silanes, differing in number of chlorine atoms and in other substituents, was explored. The fabric modification was carried out in silane solutions in anhydrous toluene and in n-hexane. Water contact angles were measured to characterize hydrophili/phobicity of the modified fabrics. Surfaces of the fibers were analyzed using SEM, EDS and ATR-FTIR. Treatment with dichlorodimethylsilane, dichloro(methyl)phenylsilane, 3-chloropropylmethyldichlorosilane and (3,3,3-trifluoropropyl)dichloromethylsilane resulted in hydrophobization, whereas trimethylchlorosilane and 3-aminopropyl(diethoxy)methylsilane were inefficient. Mechanisms of coating with the silanes were proposed. Dielectric spectroscopy of the modified fabric demonstrated that resistance was sensitive to efficiency of reactions removing water from the cotton fibers. Graphic abstract

Selective syntheses of symmetrical siloxanes and cyclotetrasiloxanes are attained from reactions of silanes and dihydrosilanes, respectively, with water, and the reactions are catalyzed by a NNNHtBu cobalt(II) pincer complex. Interestingly, when phenylsilane was subjected to catalysis with water, a siloxane cage consisting 12 silicon and 18 oxygen centers was obtained and remarkably the reaction proceeded with liberation of 3 equiv of molecular hydrogen (36 H2) under mild experimental conditions. Upon reaction of silane with different silanols, highly selective and controlled syntheses of higher order monohydrosiloxanes and disiloxymonohydrosilanes were achieved by cobalt catalysis. The liberated molecular hydrogen is the only byproduct observed in all of these transformations. Mechanistic studies indicated that the reactions occur via a homogeneous pathway. Kinetic and independent experiments confirmed the catalytic oxidation of silane to silanol, and further dehydrocoupling processes are involved in syn...

Functionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2 . In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N-formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.

This work focuses on the synthesis of polysiloxane ABx macromonomers with functional groups (A [Si-H] and B [vinyl]) incorporated on to the polymer backbone, and the coupling of these functionalities to form randomly, but highly, branched polymers. The synthesis of the ABx macromonomers was performed by the anionic copolymerization of hexamethylcyclotrisiloxane (D3) and 1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane (V3) monomers, followed by an end-capping/termination reaction with chloro(methyl)phenylsilane. The resulting macromonomers were coupled by a Pt(0) catalyzed hydrosilylation reaction, to yield highly branched polysiloxanes. The coupling reaction was investigated at different solution concentrations and using macromonomers with different extents of vinyl content. It was shown that a higher solution concentration resulted in higher degrees of chain coupling and branching, arising from efficient intermolecular coupling in preference to (the competing) intramolecular coupling (cyclization) reaction. Moreover, an increase in the mole fraction of vinyl monomer also resulted in higher levels of branching. With the ability to control the degree of branching, the strategy reported here provides a facile route to synthesize branched polysiloxanes (silicones) with varying flexibility and elasticity.

A quantum-chemical study of the reaction mechanism of 2-mercaptobenzothiazole with (iodomethyl)(dimethyl)phenylsilane in the presence of iodine was performed by the B3LYP/6-311G(d,p) method. Possible routes of formation of annulated heterocyclic systems were proposed. It was found the molecular iodine involved in the reaction has a decisive effect on the thermodynamic and kinetic characteristics of the cyclization process.

Despite being one of the most frequently carried out chemical reactions in industry, there is currently no amidation protocol that is regarded as safe, high yielding, environmentally friendly and inexpensive. The direct amidation of a carboxylic acid with an amine is viewed as an inherently good solution for developing such a protocol. Since the 1960s, there has been a gradual development in the use of silicon reagents for direct amidation. This review covers the methods published to April 2021 for silicon reagent mediated direct amidation of a carboxylic acid with an amine. This review also covers the use of polymeric SiO2 to promote direct amidation.

Hydroperoxides were synthesized in one step from various alkenes using Co(pic)(2) as the catalyst with molecular oxygen and tetramethyldisiloxane (TMDSO). The hydration product could be obtained using a modified catalyst, Co(3-mepic)(2), with molecular oxygen and phenylsilane. Formation of hydroperoxides occurred through a rapid Co─O bond metathesis of a peroxycobalt compound with isopropanol.

We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced., We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles.

Several research studies have been conducted on N-formylation of amines using phenylsilane and CO2. However, most of these studies involved tedious processes of catalyst preparation or complex procedures. In the present study, we describe the use of a simple and commercially available ZnO catalyst for selective N-formylation of amines under mild condition. High-yielding N-formylation products with good recyclability and wide substrate scope were obtained, which can promote fine chemical synthesis and CO2 capture.

International audience; We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N-oxides. Moreover, we discovered that a large variety of aliphatic amine N-oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal–free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N-oxides.Supporting information for this article is given via a link at the end of the document.

International audience; An enantioselective phosphine-catalyzed transformation has been developed for the synthesis of chiral cyclobutene triesters and fluorinated spirocyclic compounds. The strategy involved a P(III)/P(V) redox cycling process, via in situ reduction of phosphine oxide with phenylsilane. This catalytic methodology has enabled the enantioselective synthesis of functionalized cyclobutenes (24 examples, up to 94% ee). On the occasion of the extension of this study to alpha-ketoester indenone substrates, a surprising reactivity has been discovered for the synthesis of spiroindenone products.

Carbon dioxide can play a vital role as a sustainable feedstock for chemical synthesis. To be viable, the employed protocol should be as mild as possible. Herein we report a methodology to incorporate CO2 into primary, secondary, aromatic or alkyl amines catalysed by a Rh(I) complex bearing a perimidine-based NHC/phosphine pincer ligand. The periminide-based ligand belongs to a class of 6-membered NHC ligand accessed through chelate-assisted double C–H activation. N-Formylation and -methylation of amines were performed using a balloon of CO2, and phenylsilane as the reducing agent. Product selectivity between formylated and methylated products was tuned by changing the solvent, reaction temperature and the quantity of phenylsilane used. Medium to excellent conversions, as well as tolerance to a range of functional groups, were achieved. Stoichiometric reactions with reactants employed in catalysis and time course studies suggested that formylation and methylation reactions of interest begin with hydrosilylation of CO2 followed by reaction with amine substrates.

Catalytic fixation of CO2 to produce valuable fine chemicals is of great significance to develop a green and sustainable circulation of excessive carbon in the environment. Herein, a series of non-toxic, biodegradable and recyclable acetylcholine-carboxylate bio-ionic liquids with different cations and anions were simply synthesized for producing formamides and methylamines using atmospheric CO2 as a carbon source, and phenylsilane as a hydrogen donor. The selectivity toward products was tuned by altering the reaction temperature under solvent or solvent-free conditions. N-Methylamines (ca. 96% yield) were obtained in acetonitrile at 50 °C, while N-formamides (ca. 99% yield) were attained without a solvent at 30 °C. The established bio-ionic liquid catalytic system found a wide range of applicability in substrates and possessed a high potentiality in scale-up to gram-grade production. The developed catalytic system was fairly stable, which could be easily reused without an apparent loss of reactivity, possibly due to the strong electrostatic interactions between the cation and anion. The combination of experimental and computational results explicitly elucidated the reaction mechanism: PhSiH3 activated by a bio-IL was favorable for the formation of silyl formate from hydrosilylation of CO2, followed by a reaction with an amine to give an N-formamide, while an N-methylamine was formed by further hydrosilylation of the N-formamide.

We demonstrate the first metal–organic framework (MOF) that catalyzes N-methylation of amines using 1 atm CO2 and phenylsilane under ambient conditions. Compared with its homogeneous analog, the incorporation of N-heterocyclic carbene (NHC) into the MOF provides more efficient catalysis with improved reaction kinetics, turnover numbers and recyclability. Moreover, the metalated NHC functionalized MOF achieves direct N-methylation of amines bearing carboxylate moieties, which are common building blocks in pharmaceutical chemistry.

With increasing ozone depletion, ultraviolet (UV) exposure from sunlight has become a significant health risk. Although commercially available sun protectants provide reasonable protection, they have limitations in terms of safety and aesthetics. Here, we have developed biocompatible and biodegradable sunscreens by facile synthesis of organosilica nanoparticles (o-SNPs) with self-encapsulated phenyl motifs using phenylsilane precursors. The physical structure of o-SNPs is elaborately controlled such that they are large enough to reflect UVA but small enough to be imperceptible when applied on the skin. The chemically attached phenyl motifs to o-SNPs facilitate filtering UVB via their delocalized π-orbitals. The o-SNPs generate a negligible amount of reactive oxygen species under UV exposure. Ex vivo two-photon microscopy reveals that the o-SNPs tend to adhere to the outer layers of skin without further intradermal penetration, resulting in less skin irritation. In vivo UV protection tests confirmed the excellent sunscreen effect of o-SNPs compared with conventional organic and inorganic UV filters.

Six new 2-fold interpenetrated uranyl coordination polymers with two distinct types of (6,3)-net layers, (H3O)[(UO2)(L)]·H2O (1), (Hbipy)[(UO2)(L)]·H2O (2), (Hbib)[(UO2)(L)]·H2O (3), (H2dib)[(UO2)2(L)2]·H2O (4), [Zn(H2O)6][(UO2)2(L)2]·5H2O (5), and (NH4)[(UO2)(L)]·H2O (6), (bipy = 2,2′-bipyridine, bib = 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl, and dib = 1,4-di(1H-imidazol-1-yl)benzene), were hydrothermally prepared from a tripodal polycarboxylate ligand, tri(4-carboxyphenyl)phenylsilane (H3L), with different N-bearing organic templates as the stacking templates and charge compensators. Structural analyses indicate that these compounds comprise two sets of conformational supramolecular isomers because of the same framework compositions but different conformations of the carboxylate ligands. The solid-state emission spectra of compounds 1–6 were recorded. Ion-exchange studies revealed that the ammonia hydrate in 6 can be selectively substituted by alkali metal cations with appropriate ionic radii, and that ...

The reaction of H3 SiR (R=Ph, nBu) with cationic η5 -C5 Me5 - (Cp*) and benzo[h]quinolinyl-based iridacycle [1 b]+ gives rise to new [(IrH)→SiRH2 ]+ adducts. In the presence of THF these adducts readily undergo elimination of H2 gas at subambient temperature to form THF-stabilized metallacyclic IrIII silylene complexes, which were characterized in situ by NMR spectroscopy, trapped in minute amounts by reactive crystallization, and structurally characterized by XRD. Theoretical investigations (static DFT-D reaction-energy profiling, ETS-NOCV) support the promoting role of THF in the H2 elimination step and the consolidation of the Ir-to-Si interaction in the spontaneous (ΔG

Controllable hierarchical reduction of carbon dioxide (CO2) to selectively afford versatile chemicals with specific carbon oxidation state is important but still remains a huge challenge to be realized. Here, we report new zwitterionic covalent organic frameworks ([BE] X%-TD-COFs), prepared by introducing betaine groups (BE) onto the channel walls of presynthesized frameworks via pore surface engineering methodology, as the heterogeneous organocatalysts for CO2 reduction. The adjustable density of immobilized BE groups as well as good preservation of crystallinity and porosity inherited from their parent COFs endow [BE] X%-TD-COFs with highly ordered catalytic site distribution and one-dimensional mass transport pathway in favor of catalysis. By controlling the reaction temperature and amount of CO2, [BE] X%-TD-COFs present high activity in catalyzing reduction of CO2 with amine and phenylsilane (PhSiH3) to produce formamides, aminals, and methylamines, respectively, with high yield and selectivity. Furthermore, high stability and insolubility bring excellent reusability to [BE]X%-TD-COFs with well-maintained catalytic performance after four cycles of use. Notably, this is a novel example that COFs are developed as heterogeneous catalysts for hierarchical two-, four-, and six-electron reduction of CO2 with amines and PhSiH3 to form C-N bonds as well as afford C+II, C0, and C-II species efficiently and selectively.

A main group-catalyzed method for the synthesis of aryl- and heteroarylamines by intermolecular C–N coupling is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane) and a terminal hydrosilane reductant (phenylsilane) to drive reductive intermolecular coupling of nitro(hetero)arenes with boronic acids. Applications to the construction of both C(sp2)–N (from arylboronic acids) and C(sp3)–N bonds (from alkylboronic acids) are demonstrated; the reaction is stereospecific with respect to C(sp3)–N bond formation. The method constitutes a new route from readily available building blocks to valuable nitrogen-containing products with complementarity in both scope and chemoselectivity to existing catalytic C–N coupling methods.

Effects of polysilane additions on CH3NH3PbI3 perovskite solar cells were investigated. Photovoltaic cells were fabricated by a spin-coating method using perovskite precursor solutions with polymethyl phenylsilane, polyphenylsilane, or decaphenyl cyclopentasilane (DPPS), and the microstructures were examined by X-ray diffraction and optical microscopy. Open-circuit voltages were increased by introducing these polysilanes, and short-circuit current density was increased by the DPPS addition, which resulted in the improvement of the photoconversion efficiencies to 10.46%. The incident photon-to-current conversion efficiencies were also increased in the range of 400~750 nm. Microstructure analysis indicated the formation of a dense interfacial structure by grain growth and increase of surface coverage of the perovskite layer with DPPS, and the formation of PbI2 was suppressed, leading to the improvement of photovoltaic properties.

We present a combined experimental and theoretical investigation of the bimolecular gas-phase reaction of the phenyl radical (C6H5) with silane (SiH4) under single collision conditions to investigate the chemical dynamics of forming phenylsilane (C6H5SiH3) via a bimolecular radical substitution mechanism at a tetracoordinated silicon atom. Verified by electronic structure and quasiclassical trajectory calculations, the replacement of a single carbon atom in methane by silicon lowers the barrier to substitution, thus defying conventional wisdom that tetracoordinated hydrides undergo preferentially hydrogen abstraction. This reaction mechanism provides fundamental insights into the hitherto unexplored gas-phase chemical dynamics of radical substitution reactions of mononuclear main group hydrides under single collision conditions and highlights the distinct reactivity of silicon compared to its isovalent carbon. This mechanism might be also involved in the synthesis of cyanosilane (SiH3CN) and methylsilane (CH3SiH3) probed in the circumstellar envelope of the carbon star IRC+10216.

Time-resolved investigation of deuterium-substituted silylene (SiD2) generated by laser flash photolysis of deuterium-substituted phenylsilane (PhSiD3) was carried out to obtain rate constants for its bimolecular reaction with ethylene (C2H4). The reaction was studied in the gas phase over the pressure range of 1–100 Torr (in SF6 bath gas) at 295 K. The rate constants for SiD2 + C2H4 were found to be independent of pressure and close in magnitude to the rate constants for the reaction of SiH2 + C2H4 at the high-pressure limit. They are consistent with a rapid isotopic scrambling mechanism similar to that of SiH2 + C2D4. While silirane, the main product produced from this reaction, was too labile to be detected, vinylsilane, another possible product, was ruled out by gas chromatography analysis. This reaction shows similarities to those of SiH2 + H2 and its isotopic counterparts.

Two novel ferrocene-containing porous organic polymers, FPOP-1 and FPOP-2, have been prepared by Sonogashira-Hagihara coupling reactions of 1,1′-diethynylferrocene with tri(4-bromophenyl)phenylsilane or tetrakis(4-bromophenyl)silane. The resultant polymers show high thermal stability and high porosity with Brunauer-Emmer-Teller (BET) surface area of up to 954 m2 g−1 (FPOP-2) and total pore volume of up to 0.74 cm3 g−1 (FPOP-2). The porosity comparison with other ferrocene-containing porous polymers indicates that the introduction of tetrahedral silicon-centered units is beneficial to enhancing the porosity. The gas sorption investigations reveal that these polymers possess comparable CO2 capacities of 1.44 mmol g−1 (6.3%) at 273 K and 1.0 bar, and 0.91 mmol g−1 (4.0 wt%) at 298 K and 1.0 bar (FPOP-2), and comparable H2 uptakes of 7 mmol g−1 (1.4 wt%) (FPOP-2). The values are higher than other non-ferrocene-containing porous polymers with higher porosity, thereby indicating that the incorporation of ferrocene units can improve the gas sorption property. Furthermore, these results demonstrate that these materials can be promisingly utilized as solid absorbents for storing CO2 and H2.

A small-ring phosphacycloalkane (1,2,2,3,4,4-hexamethylphosphetane, 3) catalyzes intramolecular C–N bond forming heterocyclization of o-nitrobiaryl and –styrenyl derivatives in the presence of a hydrosilane terminal reductant. The method provides scalable access to diverse carbazole and indole compounds under operationally trivial homogeneous organocatalytic conditions, as demonstrated by 17 examples conducted on one-gram scale. In situ NMR reaction monitoring studies support a mechanism involving catalytic PIII/PV=O cycling, where tricoordinate phosphorus compound 3 represents the catalytic resting state. For the catalytic con-version of o-nitrobiphenyl to carbazole, the kinetic reaction order was determined for phosphetane catalyst 3 (first order), substrate (first order), and phenylsilane (zeroth order). For differentially 5-substituted 2-nitrobiphenyls, the transformation is accelerated by electron–withdrawing substituents (Hammett factor ρ = +1.5), consistent with the accrual of negative charge on the nitro substrate in the rate-determining step. DFT modeling of the turnover-limiting deoxygenation event implicates a rate-determining (3+1) cheletropic addition between the phosphetane catalyst 3 and 2-nitrobiphenyl substrate to form an unobserved pentacoordinate spiro-bicyclic dioxazaphosphetane, which decomposes via (2+2) cycloreversion giving one equivalent of phosphetane P-oxide 3•[O] and 2-nitrosobiphenyl. Experimental and computational investigations into the C–N bond forming event suggest the involvement of an oxazaphosphirane (2+1) adduct between 3 and 2-nitrosobiphenyl, which evolves through loss of phosphetane P-oxide 3•[O] to give the observed carbazole product via C–H insertion in a nitrene-like fashion.

An amide-promoted protocol was developed for the reductive functionalization of CO2 with amines/imine and phenylsilane to produce methylamine. Secondary amines and an imine were methylated successfully to methylamines with up to 98% yield under atmospheric pressure of CO2 and 80°C. Furthermore, a tentative mechanism involving amide-promoted CO2 reduction to the silyl acetal species was proposed. Striking features of this metal-free protocol are selective six-electron reduction of CO2 with hydrosilane as a reductant in the presence of amine.