312-40-3Relevant academic research and scientific papers
Isolable Silicon-Based Polycations with Lewis Superacidity
Hermannsdorfer, André,Driess, Matthias
, p. 23132 - 23136 (2020)
Molecular silicon polycations of the types R2Si2+ and RSi3+ (R=H, organic groups) are elusive Lewis superacids and currently unknown in the condensed phase. Here, we report the synthesis of a series of isolable terpyridine-stabilized R2Si2+ and RSi3+ complexes, [R2Si(terpy)]2+ (R=Ph 12+; R2=C12H8 22+, (CH2)3 32+) and [RSi(terpy)]3+ (R=Ph 43+, cyclohexyl 53+, m-xylyl 63+), in form of their triflate salts. The stabilization of the latter is achieved through higher coordination and to the expense of reduced fluoride-ion affinities, but a significant level of Lewis superacidity is nonetheless retained as verified by theory and experiment. The complexes activate C(sp3)?F bonds, as showcased by stoichiometric fluoride abstraction from 1-fluoroadamantane (AdF) and the catalytic hydrodefluorination of AdF. The formation of the crystalline adducts [2(F)]+ and [5(H)]2+ documents in particular the high reactivity towards fluoride and hydride donors.
Nucleophilic fluorination of alkoxysilane with alkali metal hexafluorophosphate 1 - part 1
Farooq, Omar
, p. 189 - 197 (1997)
Alkali metal hexafluorophosphates were used to effect nucleophilic fluorination of a few selected alkoxysilanes both in the presence and absence of polar solvents. Near-quantitative yields of fluorinated silanes were obtained using both alkoxy-equivalent of the complex salt and fluoride equivalents of alkoxysilanes. Some of the intermediate fluorosilanes and fluorophosphorus compounds were identified and the mechanism of fluorination is proposed.
METHOD FOR MANUFACTURING SILSESQUIOXANE COMPOUND
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Paragraph 0094-0095, (2021/03/05)
Provided is a method for manufacturing a silsesquioxane compound represented by general formula (III) shown below, the method having a step of reacting a compound represented by general formula (I) shown below and a compound represented by general formula (II) shown below. In general formulas (I) to (III): each of R1 and R2 independently represents a hydrogen atom, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 14 carbon atoms, an aminoalkyl group, an amino group-containing group, a nitrile group-containing group, a vinyl group-containing group, a (meth)acryloyl group-containing group, a chloro group-containing group, a bromo group-containing group, or a functional group containing a boron trifluoride-complexed amino group, each of R3 to R10 independently represents an alkyl group of 1 to 8 carbon atoms or an aryl group of 6 to 14 carbon atoms, and M represents at least one element selected from the group consisting of hydrogen, lithium, sodium and potassium.
Synthesis method of diphenyl difluorosilane
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Paragraph 0013-0023, (2020/11/23)
The invention discloses a synthesis method of diphenyl difluorosilane, belonging to the technical field of additives for battery electrolytes. The synthesis method comprises the following steps: withphenyldiethoxysilane as a raw material, adding phenyldiethoxysilane into a dry container; carrying out heating to 80-100 DEG C, and adding sodium trichloropyridinol and ethanol while stirring; then dropwise adding chlorobenzene into a mixture obtained in the previous step; after dropwise adding is finished, carrying out a reflux reaction for 3-8 hours, and conducting cooling to 30-35 DEG C; carrying out reduced-pressure suction filtration, adding sodium tetrafluoroborate into a filtrate, performing heating to 180-220 DEG C, and carrying out reacting for 4-6 hours; then conducting cooling to room temperature, performing diluting with dichloromethane, conducting quenching with water, and separating out an organic layer; and carrying out drying, carrying out vacuum concentration, and carryingout reduced-pressure distillation to obtain diphenyl difluorosilane. The synthesis method is simple, raw materials are cheap and easily available, reaction is stable, yield is high, and purity is high.
C?H and C?F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO-1234yf
Talavera, Maria,von Hahmann, Cortney N.,Müller, Robert,Ahrens, Mike,Kaupp, Martin,Braun, Thomas
supporting information, p. 10688 - 10692 (2019/07/10)
The reaction of [Rh(H)(PEt3)3] (1) with the refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt3)3] (3) by C?F bond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh3. In the presence of a fluorosilane, 3 provides a C?H bond activation followed by a 1,2-fluorine shift to produce [Rh{(E)-C(CF3)=CHF}(PEt3)3] (4). Similar rearrangements of HFO-1234yf were observed at [Rh(E)(PEt3)3] [E=Bpin (6), C7D7 (8), Me (9)]. The ability to favor C?H bond activation using 3 and fluorosilane is also demonstrated with 3,3,3-trifluoropropene. Studies are supported by DFT calculations.
Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane
Tanaka, Toru,Hasegawa, Yasuharu,Kawamori, Takashi,Kunthom, Rungthip,Takeda, Nobuhiro,Unno, Masafumi
supporting information, p. 743 - 747 (2019/03/04)
A novel synthetic method for the construction of a double-decker silsesquioxane from fluorosilanes was developed. Phenyl-substituted double-decker silsesquioxane was prepared under mild conditions by coupling difluorodiphenylsilane and a tetrasiloxanolate precursor. A similar reaction was performed using difluorovinylsilane, and a divinyl double-decker silsesquioxane was obtained. The one-step reaction of a functional difluorosilane containing an aminopropyl group afforded a novel double-decker silsesquioxane with two amino groups complexed with BF3, which can react with carboxylic acid anhydrides to afford an amide product. This synthetic method using difluorosilane is tolerant of a wide range of functional groups and is applicable to the synthesis of polycyclic silsesquioxanes bearing amino groups, which are difficult to directly obtain from dichlorosilane.
Synthesis and kinetics of disassembly for silyl-containing ethoxycarbonyls using fluoride ions
Camerino, Eugene,Daniels, Grant C.,Wynne, James H.,Iezzi, Erick B.
, p. 1884 - 1888 (2018/02/06)
In this study, a series of silyl-containing ethoxycarbonates and ethoxycarbamates on electron poor anilines and phenols were synthesized and their kinetics of disassembly determined in real-time upon exposure to fluoride ion sources at room temperature. The results provide a greater understanding of stability and kinetics for silyl-containing protecting groups that eliminate volatile molecules upon removal, which will allow for simplification of orthogonal protection in complex organic molecules.
Synthesis and applications of tert-alkoxysiloxane linkers in solid-phase chemistry
Meloni, Marco M.,White, Peter D.,Armour, Duncan,Brown, Richard C.D.
, p. 299 - 311 (2007/10/03)
Straightforward syntheses of two tert-alkoxysilyl chloride functionalised resins 3 and 31 that allow facile attachment of 1°, 2°, 3° alcohols and phenols to the solid-phase have been achieved. Resin 3 displayed useful loading levels (0.7 mmol/g), and it was stable to storage in activated form. Siloxanes from reaction of 3 with alcohols and phenols were compatible with a variety of reaction conditions commonly used in solid-phase synthesis.
Reaction of germanium tetrachloride with chloro(phenyl)silanes in the presence of aluminum chloride
Zhun',Sbitneva,Chernyshev
, p. 867 - 869 (2007/10/03)
The effect of the quantity of aluminum chloride on the direction and depth of reaction of germanium tetrachloride with chloro(phenyl)silanes of the general formula PhnSiCl4-n (n = 1 - 3) was studied to show that radical exchange between germanium and silicon is initiated only if the mixture contains no less than 2.5-5 wt % of aluminum chloride. With trichloro(phenyl)silane, the radical exchange is initiated at 5 wt % of aluminum chloride and results in exclusive formation of trichloro(phenyl)germane. The reactions of GeCl4 with dichlorodiphenylsilane and chlorotriphenylsilane in the presence of 2.5-7.5 wt % of aluminum chloride give dichlorodiphenylgermane as the major product, and at AlCl3 concentrations of above 10 wt % the major product becomes to be trichloro(phenyl)germane.
Silicon-based metalloprotease inhibitors: Synthesis and evaluation of silanol and silanediol peptide analogues as inhibitors of angiotensin-converting enzyme
Mutahi, Mwangi Wa,Nittoli, Thomas,Guo, Luxuan,Sieburth, Scott McN.
, p. 7363 - 7375 (2007/10/03)
Silanols are best known as unstable precursors of siloxane (silicone) polymers, substances generally considered stable and inert, but have the potential to mimic a hydrated carbonyl and inhibit protease enzymes. While previous testing of simple silanediol and silanetriol species as inhibitors of hydrolase enzymes found them ineffective, this study reports polypeptide mimics with a central methylsilanol [SiMeOH] or silanediol [Si(OH)2] group and their assessment as effective transition state analogue inhibitors of the well-studied metalloprotease angiotensin-converting enzyme (ACE). Central to the synthesis strategy, phenylsilanes were employed as acid-hydrolyzable precursors of the silanol group. The N-benzoyl Leu-[SiMeOH]-Gly benzyl amides proved to be stable and readily characterized. In contrast, the Leu-[Si(OH)2]-Gly structure was difficult to characterize, possibly because of self-association. Capping the silanediols with chlorotrimethylsilane gave a well-defined trisiloxane, demonstrating that the silanediol was monomeric. The Leu-[Si]-Gly structures were converted to Leu-[Si]-Ala analogues by enolate alkylation. Coupling of the silanol precursors with proline tert-butyl ester gave N-benzoyl Leu-[Si]-Gly-Pro and N-benzoyl Leu-[Si]-Ala-Pro tripeptide analogues. Treatment of these with triflic acid formed the corresponding methylsilanols and silanediols, all of which were monomeric. The silanediol tripeptide mimics inhibited ACE with IC50 values as low as 14 nM. Methylsilanols, in contrast, were poor inhibitors, with IC50 values above 3000 nM. These data, including comparisons with inhibition data from carbon analogues, are consistent with binding of the silanediols by chelation of the ACE active site zinc, whereas the methylsilanols ligate poorly.
