2157-42-8

Upstream product

• 110-86-1 pyridine 
• 78-10-4 tetraethoxy orthosilicate 
• 1112-48-7 triethyl-bromo-silane 
• 64-17-5 ethanol 
• 998-30-1 Triethoxysilane 
• 4667-99-6 chlorotriethoxysilane 
• 141-52-6 sodium ethanolate 
• 122-51-0 orthoformic acid triethyl ester 
• 109-57-9 Allylthiourea 
• 592-41-6 1-hexene 
• 103-85-5 monophenylthiourea 
• 18134-84-4 hexaisocyanato disiloxane 
• 29167-65-5 tris(silatranyloxyethyl)amine 
• 7647-01-0 hydrogenchloride 

Downstream Products

• 78-10-4 tetraethoxy orthosilicate 
• 75144-60-4 hexavinyldisiloxane 
• 75-00-3 chloroethane 

Relevant academic research and scientific papers

Chemistry of Silicon-Nitrogen Compounds, CLXVI: Organylamino Substitutions on Hexachlorodisiloxane

Reaction of hexachlorodisiloxane with primary and secondary amines leads - in dependence of stoichiometry - to numerous partially and totally organylamino substituted disiloxanes.Partially aminosubstituted chlorodisiloxanes are very sensitive to moisture and can be converted into disiloxanes with different organylamino groups.Exhaustive alkanolysis substitutes amino as well as chloro groups giving hexaalkoxydisiloxanes, but partial alkanolysis may substitute amino in preference to chloro groups.Mass spectra can be interpreted by abstraction of RR'N., RR'N+, RR'NH and (RR'N minus H) units.Most of the compounds are colourless liquids but hexakis(piperidino)-disiloxane melts at 270 deg C.

Direct synthesis of tetraalkoxysilanes from silica and alcohols

A new simple and efficient process for synthesizing tetraalkoxysilanes (TROS) directly from silica and alcohols was developed using molecular sieves as dehydrating agents. Using this method, a variety of TROS (R = ethoxy, n-propoxy, or n-butoxy) were obtained over 70% yields within 6 h. We also employed various natural silica sources in this process for practical applications.

A new route to silicon alkoxides from silica

A novel route to tetraethoxysilane and other silicon alkoxides is described, from amorphous silica (SiO2·H2O) as the raw material. The reaction of amorphous silica with triethanolamine is enhanced by using an alkali metal hydroxide catalyst, to form a range of triethanolamine-substituted silatrane species. These can undergo alkoxide exchange in acidic alcohols to form alkoxysilatranes, tetraalkoxysilanes, hexaalkoxydisiloxanes and higher siloxanes. Reaction of triethanolamine-substituted silatranes with acetic anhydride produces acetoxysilatrane. Products were identified by multinuclear (1H, 13C and 29Si) magnetic resonance spectroscopy, electrospray mass spectrometry or high-resolution gas chromatography electron impact mass spectrometry.

Sustainable Catalytic Synthesis of Diethyl Carbonate

New sustainable approaches should be developed to overcome equilibrium limitation of dialkyl carbonate synthesis from CO2 and alcohols. Using tetraethyl orthosilicate (TEOS) and CO2 with Zr catalysts, we report the first example of sustainable catalytic synthesis of diethyl carbonate (DEC). The disiloxane byproduct can be reverted to TEOS. Under the same conditions, DEC can be synthesized using a wide range of alkoxysilane substrates by investigating the effects of the number of ethoxy substituent in alkoxysilane substrates, alkyl chain, and unsaturated moiety on the fundamental property of this reaction. Mechanistic insights obtained by kinetic studies, labeling experiments, and spectroscopic investigations reveal that DEC is generated via nucleophilic ethoxylation of a CO2-inserted Zr catalyst and catalyst regeneration by TEOS. The unprecedented transformation offers a new approach toward a cleaner route for DEC synthesis using recyclable alkoxysilane.

BRANCHED ORGANOSILOXANES USED AS HEAT TRANSFER FLUID

The invention relates to a method for operating a system at an operating temperature of between 300° C. and 500° C., using a heat transfer fluid comprising branched siloxanes of general formula (I) (R3SiO1/2), (SiO4/2) in which w represents integral values of between 4 and 20, z represents integral values of between 1 and 15, and R represents a methyl group, the sum of the fractions of all siloxanes of general formula (1) being at least 95 mass %, in relation to the whole heat transfer fluid.

Reaction of silicon with alcohols in autoclave

A reaction of activated silicon with alcohols in an autoclave at 240—270 °C was studied. It was found that primary alcohols form tetraalkoxysilanes Si(OR)4 with high selectivity (up to 97%), while the secondary PriOH gave a mixture of compounds HSi(OPri)3, Si(OPri)4, HSi(OPri)2OSi(OPri)2H, HSi(OPri)2OSi(OPri)3, and Si(OPri)3OSi(OPri)3 with the predominance of trialkoxysilane (up to 67%). Carrying out the reaction under the indicated conditions has the advantage of experimental simplicity, reagent availability, high conversion of silicon, good isolated yields of products.

Bis(acetylacetonato)Ni(II)/NaBHEt3-catalyzed hydrosilylation of 1,3-dienes, alkenes and alkynes

The utility of commercially available Ni(II) salts, Ni(acac)2 (acac = acetylacetonato) (1a) and its derivatives bis(hexafluoroacetylacetonato)nickel(II) (1b) and bis(2,2,6,6-tetramethyl-3,5-heptanedionato)nickel(II) (1c) as versatile hydrosilylation catalyst precursors is described. Complexes 1a-c catalyze 1,4-selective hydrosilylation of 1,3-dienes in the presence of NaBHEt3 at ambient temperature. The reactions exhibit good regioselectivity to give the branched isomers as major products. The catalytic system also catalyzes hydrosilylation of alkenes including industriary important siloxy-, amino-, and epoxy-substituted ones as well as both terminal and internal alkynes.

Mononuclear Heteroscorpionate Zwitterionic Zinc Terminal Hydride: Synthesis, Reactivity, and Catalysis for Hydrosilylation of Aldehydes

Treatment of heteroscorpionate zinc benzyloxy complex LZnOBn (1, L = (MePz)2CP(Ph)2NPh, MePz = 3,5-dimethylpyrazolyl) with phenylsilane (PhSiH3) gave a zinc hydride complex LZnH (2) containing a rare terminal hydride fragment. X-ray diffraction analysis and the DFT calculation confirm the zwitterionic structure of complex 2. The stoichiometric reaction of 2 with CS2 readily afforded a dithioformate complex LZnSCH(S) (3) of the C = S insertion into the Zn-H product. Moreover, complex 2 was an efficient catalyst for the hydrosilylation reaction of a series of silanes and aldehydes under mild conditions, featuring excellent functional group tolerance. The preliminary mechanistic study revealed that both zinc benzyloxy complex 1 and zinc hydride complex 2 were involved in the hydrosilylation process as the reaction intermediates. (Chemical Equation Presented).

Copper-catalyzed formic acid synthesis from CO2 with hydrosilanes and H2O

A copper-catalyzed formic acid synthesis from CO2 with hydrosilanes has been accomplished. The Cu(OAc)2?H 2O-1,2-bis(diphenylphosphino)benzene system is highly effective for the formic acid synthesis under 1 atm of CO2. The TON value approached 8100 in 6 h. The reaction pathway was revealed by in situ NMR analysis and isotopic experiments.

Hydrosilylation of cyclohexene and allyl chloride with trichloro-, dichloro(methyl)-, and chlorodimethylsilanes in the presence of Pt(0) complexes

Hydrosilylation of cyclohexene and allyl chloride in the presence of Pt(0) complexes with tetramethyldivinyldisiloxane (Karstedt catalyst) and hexavinyldisiloxane was studied. It was shown that these catalysts are much more active in the hydrosilylation of cyclohexene with trichloro-, dichloro(methyl)-, and chlorodimethylsilane than the Pt(II)-containing Speier catalyst. In the hydrosilylation of allyl chloride in the presence of Pt(0) complexes, the ratio of the fraction of addition products to the fraction of reduction products increases from 5.7 (Speier catalyst) to 10-16. Quantum-chemical calculations showed that Pt(0) complexes are more active than Pt(II) complexes on the stage of formation of platinum silicon hydride complexes. Pleiades Publishing, Inc., 2006.