Trimethylsilyl Methyl Research Articles

1,2-Bis[bis(pyridin-2-yl-methyl)phosphino]ethane and its PdCl2-based complex: synthesis and crystal structure

1,2-Bis[bis(pyridin-2-ylmethyl)phosphino]ethane, R2PCH2CH2PR2 (R = 2-PyCH2), has been synthesized in 92% yield via the reaction of Cl2PCH2CH2PCl2 with 2-[(trimethylsilyl)methyl]pyridine. Treatment of this phosphine with Pd(COD)Cl2 affords chelating complex of [PdLCl2] type, wherein the Pd(II) ion displays a square-planar [Pd@Cl2P2] geometry.

Visible-light triggered photochemical reaction for the synthesis of dumbbell-like bis aminomethyl-1, 2 dihydrofullerene dimers via addition of α-amino radicals

Single electron transfer-mediated photochemical reaction of C60 fullerene with simple bis-α-silyl tertiary alkyl/benzyl amines has been developed for the straightforward and valuable construction of dumbbell-like single-bonded bis aminomethyl-1, 2-dihydrofullerenes under milder condition. In these studies of photoinduced SET reactions, α-amino radicals serve as the reactive key intermediate, which was selectively obtained by using the bis-α-silyl tertiary alkyl amines as starting materials. The present strategy was compatible with various 2, 2′-oxybis (ethane-2, 1-diyl) bis (2-(alkyl/benzyl-substituted ((trimethylsilyl) methyl) amino) acetate) for the synthesis of bis aminomethyl-1, 2-dihydrofullerenes under a photocatalyst-free condition.

Cold Plasma Deposition of Polymeric Nanoprotrusion, Nanoparticles, and Nanofilm Structures on a Slide Glass Surface

In this study, we coated the surface of glass slides with nanoprotrusion, nanoparticles, and nanofilm structures by one-step plasma deposition of three vinyl monomers. Three functional vinyl monomers with symmetrical polarity sites were used: methyl methacrylate (MMA), trifluoro methylmethacrylate (TFMA), and trimethylsilyl methyl methacrylate (TSMA). The TSMA/MMA (80/20, mol-%) nanoprotrusion-coated surface of slide glass was superhydrophobic, with a 153° contact angle. We also evaluated the transmittance (%) of the slide glass with nanoprotrusions in the infrared (IR) (940 nm), ultraviolet (365 nm) and visible light (380–700 nm) regions. The obtained nanoprotrusion structure surface of slide glass created by plasma deposition transmits more than 90% of visible light.

A New Strategy for the Synthesis of Organosilicon Compounds of Cyclopropane Derivatives

The one-pot reaction of tetra-substituted cyclopropyl benzyl bromide with tris(trimethylsilyl)methyllithium (TsiLi) and carbon disulfide resulted in 3-(4-((((trimethylsilyl)ethynyl)thio)methyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (3) and 3-(4-((trimethylsilyl)methyl)phenyl)cyclopropane-1,2-dicarbonitrile (4) in excellent yield. The reaction in the absence of carbon disulfide yielded 3-(4-(2,2,2-tris(trimethylsilyl)ethyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (5) in excellent yield at 0°C to room temperature. All structures were characterised by IR, 1H NMR, and 13C NMR spectroscopies. The reaction mechanisms are discussed.

Convenient One-Pot Synthesis of Allylsilanes from Enolizable Ketones

A convenient one-pot synthesis of allylsilanes from enolizable methyl aryl ketones has been developed. The first step involves nucleophilic addition of the trimethylsilylmethyl group to ketones using the alkylation method developed by Ishihara with slight modification to generate the corresponding β-silylalkoxides. The second step entails addition of diisobutylaluminum chloride and heating at about 130 °C overnight to afford allylsilanes in fair yields.

Bio-oil from microwave assisted pyrolysis of food waste-optimization using response surface methodology

Municipal solid waste (MSW) contains on an average 40% food waste and needs to be managed in an environment friendly manner. Food wastes have high energy content and offer a good potential feed stock for pyrolysis. Microwave assisted pyrolysis of food waste at different microwave power levels has been carried out in the present study. Maximum bio-oil yield of 30.24 wt.% is obtained under the optimized pyrolysis conditions of 400 °C temperature, 30 min residence time and 50 mL min-1 of nitrogen flow rate at the microwave power of 450 W. The regression model with 95% confidence level resulted in the high value of R2 = 95.4% with R2 adjusted = 91.2% indicates a very good or excellent fit of the data to the model. Main functional groups as detected by the Fourier transform infrared (FTIR) analysis are alcohols, alkenes, aromatic compounds, primary and secondary amines, carboxylic acid, esters and phenols. Oxygenated and non oxygenated compounds, nitrogenated compounds and other compounds such as phosphine, methyl-, propane, 2-fluoro-, (2-hydroxyethyl) trimethylsilyl methyl sulfide, and 1,3-bis(2-hydroxymethyl)urea have been identified by the gas chromatography/mass spectrometry (GC-MS) analysis. The heating value of the bio-oil was 23.94 MJ kg−1.

Direct Synthesis of Heavy Grignard Reagents: Challenges, Limitations, and Derivatization

The direct synthesis of organocalcium compounds (heavy Grignard reagents) by the reduction of organyl halides with activated calcium powder succeeded in a straightforward manner for organic bromides and iodides that are bound at sp2 -hybridized carbon atoms. Extension of this strategy to alkyl halides was very limited, and only the reduction of trialkylsilylmethyl bromides and iodides with activated calcium allowed the isolation of the corresponding heavy Grignard reagents. Substitution of only one hydrogen atom of the methylene moiety by a phenyl or methyl group directed this reduction toward the Wurtz-type coupling and the formation of calcium halide and the corresponding C-C coupling product. The stability of the methylcalcium and benzylcalcium derivatives in ethereal solvents suggests an unexpected reaction behavior of the intermediate organyl halide radical anions. Quantum chemical calculations verify a dependency between the ease of preparative access to organocalcium complexes and the C-I bond lengths of the organyl iodides. The bulkiness of the trialkylsilyl group is of minor importance. Chloromethyltrimethylsilane did not react with activated calcium; however, halogen-exchange reactions allowed the isolation of [Ca(CH2 SiMe3 )(thf)3 (μ-Cl)]2 . Furthermore, the metathetical approach of reacting [Ca(CH2 SiMe3 )I(thf)4 ] with KN(SiMe3 )2 and the addition of N,N,N',N'',N''-pentamethyldiethylenetriamine (pmdeta) allowed the isolation of heteroleptic [CaCH2 SiMe3 {N(SiMe3 )2 }(pmdeta)]. In the reaction of this derivative with phenylsilane, the trimethylsilylmethyl group proved to be more reactive than the bis(trimethylsilyl)amido substituent.

New Regio- and Stereoselective Cascades via Unstabilized Azomethine Ylide Cycloadditions for the Synthesis of Highly Substituted Tropane and Indolizidine Frameworks.

Multisubstituted tropanes and indolizidines have been prepared with high regio- and stereoselectivity by the [3+2] cycloaddition of unstabilized azomethine ylides generated from readily prepared trimethylsilyl-substituted 1,2-dihydropyridines via protonation or alkylation followed by desilylation. Starting from 1,2-dihydropyridines bearing a ring trimethylsilyl substituent at the 6-position, an intermolecular alkylation/desilylation provides endocyclic unstabilized ylides that successfully undergo cycloaddition with a range of symmetrical and unsymmetrical alkyne and alkene dipolarophiles to afford densely substituted tropanes incorporating quaternary carbons in good yields and with high regio- and stereoselectivity. Additionally, an intramolecular alkylation/desilylation/cycloaddition sequence provides convenient and rapid entry to bridged tricyclic tropane skeletons, allowing for five contiguous carbon stereocenters to be set in a single experimental operation and under mild conditions. Starting from 1,2-dihydropyridines with trimethylsilylmethyl groups on nitrogen, protonation followed by desilylation generates exocyclic unstabilized ylides that undergo cycloaddition with unsymmetrical alkynes to give indolizidines with good regio- and stereoselectivity. N-Trimethylsilylmethyl-1,2-dihydropyridines can also be alkylated and subsequently desilylated to give endocyclic unstabilized ylides that undergo intermolecular cycloadditions with carbonyl compounds to give bicyclic oxazolidine products in good overall yields. Moreover, an intramolecular alkylation/desilylation/cycloaddition sequence with the N-trimethylsilylmethyl-1,2-dihydropyridines affords tricyclic indolizidines that incorporate quaternary carbons and up to five stereocenters with good to excellent regio- and diastereoselectivity.

Synthesis of 4-(trifluoromethyl)pyrrolidines Containing Sulfonyl, Iminosulfonyl, Sulfamide, or Phosphonyl Substituent

New 4-(trifluoromethyl)pyrrolidines containing sulfonyl, iminosulfonyl, sulfamide, or phosphonyl group at position 3 were synthesized by 1,3-dipolar cycloaddition reactions of 3,3,3-trifluoropropene derivatives to azomethine ylide generated in situ from N-benzyl-N-(methoxymethyl)-N-[(trimethylsilyl)methyl]amine.

Trimethylsilylmethylcalcium Iodide, an Easily Accessible Grignard-Type Reagent of a Heavy Alkaline Earth Metal

The direct synthesis of iodomethyltrimethylsilane with calcium and magnesium in ether yields the corresponding ether adducts [(thf)4Ca(I)(CH2SiMe3)] (1a) and [(Et2O)2Mg(I)(CH2SiMe3)] (2a). The 1,4-dioxane method allows shifting the Schlenk equilibrium toward bis(trimethylsilylmethyl)magnesium 2b. After substitution of ligated thf ligands by tetrahydropyran (thp) crystalline [(thp)4Ca(I)(CH2SiMe3)] (1b) can be isolated. The Ca–C and Ca–I bond lengths of 252.7(3) and 319.11(3) pm represent characteristic values. Steric repulsion between ligated thp ligands and the rather bulky trimethylsilylmethyl group widens the Ca–C–Si angle to 131.19(14)°. NMR data and quantum chemical studies support that hyperconjugative effects might be operative, leading to a shortened Si–C bond of this Ca–C–Si fragment.

Synthesis of 5-(polyfluoroalkyl)-1,3-thiazolidines from polyfluoroalkanethiocarboxylic acid derivatives

Novel 5-(polyfluoroalkyl)-1,3-thiazolidines were synthesized by the reaction of polyfluoroalkanethiocarboxylic acid derivatives with azomethine ylide, generated in situ via acid-catalyzed desilylation of N-benzyl-N-(methoxymethyl)-N-[(trimethylsilyl)methyl]amine.

Reactions of 2-[Lithio(trimethylsilyl)methyl]-2H-tetrazoles: Synthesis of 2-[1-(Trimethylsilyl)alkyl]-2H-tetrazoles and (2H-Tetrazol-2-yl)acetates

The reaction of 2-[(trimethylsilyl)methyl]-2 H -tetrazoles with various alkyl halides and carbonates using n -butyllithium or lithium diisopropylamide (LDA) gave 2-[1-(trimethylsilyl)alkyl]-2 H -tetrazoles and (2 H -tetrazol-2-yl)acetates as useful synthons of modified tetrazoles.

Neutral and Cationic Zirconium Hydrides Supported by a Dianionic (NNNN)-Type Macrocycle Ligand

Hydrogenation of bis(trimethylsilylmethyl) zirconium complex [Zr(Me2TACD)(CH2SiMe3)2] (1), prepared by reacting [Zr(CH2SiMe3)4] with 1,7-dimethyl-1,4,7,10-tetraazacyclododecane (Me2TACD)H2, gave dinuclear alkyl hydride complex [Zr(Me2TACD)(CH2SiMe3)2(μ-H)2Zr(Me2TACD)] (2). According to NMR spectroscopic and single-crystal X-ray diffraction studies, 2 exhibits a Cs-symmetrical structure with two distinct zirconium centers, one eight- and the other seven-coordinate, bridged by an amido donor and two hydrides. Abstraction of the trimethylsilylmethyl groups by the weak Bronsted acid [NEt3H][B(3,5-C6H3Cl2)4] gave the monocationic mono(alkyl) dihydride [Zr(Me2TACD)(CH2SiMe3)(μ-H)2Zr(Me2TACD)][B(3,5-C6H3Cl2)4] (3) and the dicationic hydride complex [Zr(Me2TACD)(THF)2(μ-H)2Zr(Me2TACD)][B(3,5-C6H3Cl2)4]2 (4). X-ray crystallography of the cationic complexes 3 and 4 revealed a Cs-symmetrical dinuclear structure derived from that of 2.

Red fluorescent materials based on julolidine/chromene with the bulky tert-butyl and trimethylsilyl substituents for organic light-emitting diodes.

In this work, we designed and synthesized two red emitters 2-(6,8-di-tert-butyl-2-(2-(1,1-dimethyl-7-(trimethylsilyl)-7-((trimethylsilyl)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl)vinyl)-4H-chromen-4-ylidene)malononitrile (Red 1) and 2-(6,8-di-tert-butyl-2-(2-(1,1,7-trimethyl-7-t-butyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl)vinyl)-4H-chromen-4-ylidene)malononitrile (Red 2). To explore the electro-luminescence properties of these materials, multilayered OLEDs using these materials as dopants in a Alq3 host were fabricated. Particularly, by using Red 1 as a dopant in emitting layer, device 1 showed the luminous and power efficiencies of 0.81 cd/A and 0.43 lm/W at 20 mA/cm2, respectively. The CIE coordinates of this device was (0.65, 0.34) at 7.0 V, which is close to the NTSC standard CIE coordinates of (0.67,0.32) for red emission.

Conformational structure of N-(silylmethyl)anilines PhNHCH2SiMe n (OEt)3-n (n = 0–3)

As show the data of IR spectroscopy and quantum-chemical calculations (B3LYP/6-311+G**), N-(silylmethyl)anilines PhNHCH2SiMen(OEt)3−n in inert media have an intramolecular hydrogen bond NH⋯OSi. N-[(Trimethylsilyl)methyl]aniline PhNHCH2SiMe3 in inert solvents exists as a mixture of two conformers close in energy.

Novel germanetellones: XYGeTe (X, Y = H, F, Cl, Br, I and CN) – structures and energetics. Comparison with the first synthetic successes

No stable germanetellone was described until Tbt(Dis)Ge=Te and Tbt(Tip)Ge=Te (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, Dis = bis(trimethylsilyl)methyl and Tip = 2,4,6-triisopropylphenyl) were reported in 1997. Following these initial experiments, there has arisen considerable interest in Ge[double bond, length as m-dash]Te systems. An obvious question is: why have the simple XYGe=Te (X, Y = H, F, Cl, Br, I and CN) molecules not yet been isolated? In view of the present situation, theoretical information may be of great help for further advances in germanetellone chemistry. A systematic investigation of the XYGe=Te molecules is carried out using the second order Møller-Plesset perturbation theory (MP2) and density functional theory (DFT). The structures and energetics, including ionization potentials (IPad and IPad(ZPVE)), four different forms of neutral-anion separations (EAad, EAad(ZPVE), VEA and VDE) and the singlet-triplet gaps, are reported. The electronegativity (χ) reactivity descriptor for the halogens (F, Cl, Br and I) and the natural charge separations of the Ge=Te moiety are used to assess the interrelated properties of germanetellone and its derivatives. The results are analyzed, discussed and compared with analogous studies of telluroformaldehyde, silanetellone and their derivatives. The thermodynamic viabilities of some of the novel germanetellones have also been evaluated in terms of the bond dissociation enthalpies of Tbt(Dis)Ge=Te and Tbt(Tip)Ge=Te. The simple mono-substituted germanetellones appear to be slightly more thermodynamically favored than Tbt(Dis)Ge=Te and Tbt(Tip)Ge=Te, since the bond dissociation enthalpies of these kinetically stabilized germanetellones are about 28 and 51 kcal mol(-1) lower, respectively.

Synthesis, Characterization, and Structure of Some Silicon Containing Diorganotin(IV) Complexes of Salicylaldehyde Thiosemicarbazones

Four diorganotin(IV) complexes, bis[(trimethylsilyl)methyl]tin salicylaldehyde thiosemicarbazonate monohydrate(1), bis[(trimethylsilyl)methyl]tin 3-methoxysalicylaldehyde thiosemicarbazonate (2), bis[(trimethylsilyl)methyl]tin 5-tert-butyl-3-methylsalicylaldehyde thiosemicarbazonate (3), and bis[(trimethylsilyl)methyl]tin 2-oxylnaphthaldehyde thiosemicarbazonate (4) have been synthesized by reactions of (Me3SiCH2)2SnCl2 with the corresponding semicarbazone. The four complexes were characterized by IR and NMR spectroscopy and elemental analyses. The X-ray studies of compounds 1 and 4 showed that the thiosemicarbazone ligands act as tridentate ligands chelating to the central tin atoms, and thus the tin atoms were five coordinated in trigonal bipyramidal geometry for both compounds. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Syntheses and Characterization of Cyclohexyl(phenyl)-[(trimethylsilyl)methyl]stannyl Aromatic Carboxylates

合成了11个芳香酸环己基（苯基）[（三甲基硅基）甲基]锡酯,并通过1H NMR,13C NMR,IR和元素分析对目标化合物结构进行了表征.生物活性测试的初步结果表明,该类化合物具有一定的杀螨活性.

ChemInform Abstract: Chemistry of Aromatic Compounds Containing a Heavier Group 14 Element

AbstractReview: ca. 50 refs.

Hydroboration of Disilyne RSi≡SiR (R = SiiPr[CH(SiMe3)2]2), Giving Boryl-Substituted Disilenes

The reaction of 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasila-2-yne (1) with hydroboranes afforded boryl-substituted disilenes R(R′2B)Si═SiHR 3a and 3b (R = SiiPr[CH(SiMe3)2]...