- Efficient Conversion of Biomass Derived Levulinic Acid to γ-Valerolactone Using Hydrosilylation
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Converting biomass into value-added chemicals is of significant interest and we report an efficient hydrosilylation to convert levulinic acid to γ-valerolactone using cost-effective silanes such as PMHS and TMDS with B(C6F5)3 as catalyst. This metal free methodology works at room temperature reaching TONs and TOFs up to 16000 and 2000 h?1. Insights into the reaction mechanism are reported.
- Garg, Nitish K.,Schmalz, Veronika,Johnson, Magnus T.,Wendt, Ola F.
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supporting information
p. 5243 - 5247
(2021/10/19)
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- Use of Silylated Formiates as Hydrosilane Equivalents
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The present invention relates to a method for preparing organic compounds of formula (I) by reaction between a silylated formiate of formula (II) and an organic compound in the presence of a catalyst and optionally of an additive. The invention also relates to use of the method for preparing organic compounds of formula (I) for the preparation of reagents for fine chemistry and for heavy chemistry, as well as in the production of vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, and pesticides.
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Paragraph 0514
(2021/09/26)
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- Production of acyloxysilane
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[A] a method for producing functional chemicals useful as efficient acyloxysilane. The silanol Si-to-OH bond [a], in the presence of a catalyst, comprising the step of reacting a carboxylic acid anhydride, Si-to-OCO bond (OCO is, oxycarbonyl groups (=O) O-a C shown. ) Having an acyloxysilane manufacturing method, wherein the catalyst, or (2) (1) production of acid catalyst selected from the next acyloxysilane. (1) 3 - 15 Of the periodic table of the first group the first group element selected from the perchlorate salt, trifluoromethanesulfonic acid salt, a bis (trifluoromethanesulfonyl imide) salt, lithium hexafluorophosphate salt, chloride, or bromide; inorganic acids; or an organic acid. (2) Inorganic or organic solid acid compounds[Drawing] no
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Paragraph 0059-0064
(2021/10/30)
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- Silylation of O-H bonds by catalytic dehydrogenative and decarboxylative coupling of alcohols with silyl formates
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The silylation of O-H bonds is a useful methodology in organic synthesis and materials science. While this transformation is commonly achieved by reacting alcohols with reactive chlorosilanes or hydrosilanes, we show herein for the first time that silylformates HCO2SiR3 are efficient silylating agents for alcohols, in the presence of a ruthenium molecular catalyst.
- Chauvier, Clément,Godou, Timothé,Cantat, Thibault
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p. 11697 - 11700
(2017/11/03)
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- An efficient solvent-free route to silyl esters and silyl ethers
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Dinuclear metal complexes, especially (p-cymene)ruthenium dichloride dimer {[RuCl2(p-cymene)]2}, have been found to exhibit high catalytic performance for the dehydrosilylation of various kinds of carboxylic acids and alcohols. The dehydrosilylation with [RuCl2(p-cymene)] 2 proceeded efficiently with only one equivalent of silane with respect to substrate (carboxylic acids or alcohols) under solvent-free conditions to give the corresponding silyl esters and ethers in excellent yields with a high turnover number (TON) and frequency (TOF). The 1H NMR spectrum of a toluene-d8 solution of [RuCl2(p-cymene)] 2 and a silane showed a signal assignable to the ruthenium hydride species. In contrast, no new signals were detected in the 1H NMR spectrum of a toluene-d8 solution of [RuCl2(p-cymene)] 2 and a carboxylic acid or an alcohol. There-fore, the ruthenium metal in [RuCl2(p-cymene)]2 activates a silane to afford the hydride intermediate, possibly a silylmetal hydride species. Then, the nucleophilic attack of a substrate (carboxylic acid or alcohol) to the hydride intermediate proceeds to give the corresponding silylated product. The present dehydrosilylation with an optically active silane proceeded exclusively under inversion of stereochemistry at the chiral silicon center, suggesting that the nucleophilic attack of a substrate to the hydride intermediate occurs from the backside of the ruthenium-silicon bond.
- Ojima, Yuko,Yamaguchi, Kazuya,Mizuno, Noritaka
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experimental part
p. 1405 - 1411
(2009/12/07)
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- Acyl iodides in organic synthesis: IX. Cleavage of the Si-O-C and Si-O-Si moieties
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Reactions of acyl iodides RCOI (R = Me, Ph) with organosilicon compounds involve cleavage of the Si-O-C and Si-O-Si fragments. Acetyl iodide reacts with alkyl(alkoxy)silanes with evolution of heat, and cleavage of the Si-O bond results in the formation of oligo-or polysiloxanes, alkyl iodides, and alkyl acetates. 1,3-Diacetoxytetramethyldisiloxane is formed in the reaction of acetyl iodide with dimethoxy(dimethyl)silane. Acyl iodides readily react with 1-ethoxysilatrane to give 1-acyloxysilatranes as a result of cleavage of the C-O bond. The reaction of acetyl iodide with hexaethyldisiloxane yields triethylsilyl acetate and triethyliodosilane, while in the reaction with octamethyltrisiloxane iodo(trimethyl)silane and dimethyl(trimethylsiloxy)silyl acetate are obtained. Nauka/Interperiodica 2007.
- Voronkov,Trukhina,Belousova,Kuznetsova,Vlasova
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p. 501 - 506
(2008/02/02)
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- Two new catalysts for the dehydrogenative coupling reaction of carboxylic acids with silanes - Convenient methods for an atom-economical preparation of silyl esters
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Tris(triphenylphosphine)cuprous chloride [Cu(PPh3)3Cl] has been found to be an efficient catalyst for the dehydrosilylation of carboxylic acids with silanes. In the presence of 4 mol% Cu(PPh3)3Cl, dehydrosilylation reactions in acetonitrile afforded the corresponding silyl esters at 80°C in good yields. It was noted that triphenylphosphine itself also functions as an adequate catalyst for the reaction. Copyright Taylor & Francis Group, LLC.
- Liu, Guo-Bin,Zhao, Hong-Yun,Thiemann, Thies
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p. 2717 - 2727
(2008/02/12)
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- Acyl iodides in organic synthesis: X. Reactions with triorganylsilanes and triphenylgermane
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Reaction of acyl iodides RCOI (R = Me, Ph) with triorganylsilanes R′2R″SiH in toluene gives 50-60% of the corresponding triorganyliodosilanes R′2R″SiI. Triethylsilane reacts with the same acyl iodides under solvent-free conditions to afford the corresponding aldehyde and triethyliodosilane as primary products. Triethyliodosilane undergoes subsequent transformations into hexaethyldisiloxane and triethyl(acyloxy)silane Et3SiOCOR (R = Me, Ph). Reactions of acyl iodides RCOI (R = Me, Ph) with triphenylgermane in the absence of a solvent lead to formation of iodo(triphenyl)germane in more than 90% yield.
- Voronkov,Trukhina,Belousova,Tsyrendorzhieva,Vlasova
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experimental part
p. 1751 - 1753
(2009/09/29)
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- Process for the preparation of vinyl- or allyl-containing compounds
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A vinyl- or allyl-containing compound represented by following Formula (3): wherein R2, R3, R4, R5, and R6 each represent hydrogen atom or a nonmetallic atom-containing group; R7 represents a nonmetallic atom-containing group; Y represents a group selected from the group consisting of —Si(R8) (R9) —, —Si(R10) (R11)—O—, the left hand of which is combined with R7, and —NR12—, wherein R8, R9, R10, R11, and R12 each represent hydrogen atom or a nonmetallic atom-containing group; and “n” represents 0 or 1, is prepared by reacting a vinyl or allyl ester compound represented by following Formula (1): wherein R1 represents hydrogen atom or a nonmetallic atom-containing group; R2, R3, R4, R5, R6, and “n” are as defined above, with a compound represented by following Formula (2): [in-line-formulae]R7—Y—H ??(2)[/in-line-formulae] wherein R7 and Y are as defined above, in the presence of a transition element compound.
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Page/Page column 5-6
(2008/06/13)
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- Preparation of silyl esters by ZnCl2-catalyzed dehydrogenative cross-coupling of carboxylic acids and silanes
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An efficient route to silyl esters by dehydrogenative cross-coupling of silanes and carboxylic acids was investigated. Treatment of silanes and carboxylic acids in the presence of 15mol% of ZnCl2 in DMF at 120 °C afforded the corresponding silyl esters in good yields under relatively mild conditions. Georg Thieme Verlag Stuttgart.
- Liu, Guo-Bin
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p. 1431 - 1433
(2007/10/03)
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- Silyl methallylsulfinates: Efficient and powerful agents for the chemoselective silylation of alcohols, polyols, phenols and carboxylic acids
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Alcohols, phenols and carboxylic acids are silylated with very good yields in the presence of silyl methallylsulfinates under non-basic conditions and with the formation of volatile co-products. The Royal Society of Chemistry 2005.
- Huang, Xiaogen,Craita, Cotinica,Awad, Loay,Vogel, Pierre
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p. 1297 - 1299
(2008/03/28)
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- An efficient Pd-catalyzed route to silyl esters
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A one-step, highly selective catalytic route to silyl esters is reported. Commercially available silanes with Si-H functionality were converted to silyl or siloxy esters in the presence of Pd(OAc)2 under mild reaction conditions. This protocol was found to be equally applicable for the modification of multiple silicon centers in one framework and lead to the corresponding polysilyl esters in high yields. A comparison of catalytic efficiency of Pd(OAc)2 versus Pd on carbon was also undertaken.
- Chauhan, Moni,Chauhan, Bhanu P. S.,Boudjouk, Philip
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p. 1027 - 1029
(2007/10/03)
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- Thermolysis of alkoxyaluminum and siloxyaluminum acylates
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Thermolysis of alkoxyaluminum acylates (RO)nAl(OCORt)3-n (n = 1, 2; R = i-Pr, s-Bu, t-Bu, Rt = Ph, CH2I; R = PhCH2, Rt = Me, Et, Ph; R = Me3Si, Et3Si, Rt = Me) was studied. The main direction of thermolysis of derivatives of primary and secondary alcohols and of unsubstituted carboxylic acids is ester and alcohol formation. Trialkylsiloxyaluminum acylates termolyze to give in the first stage no other products than trialkylacyloxysilanes. Thermolysis of iodoacylates (RO)2AlOCOCH2I (R = Pr, s-Bu) involves oxidation of the alkoxy group to carbonyl compounds with simultaneous formation of a ketene and hydrogen iodide. tert-Butoxyaluminum acylates regardless of the structure of substituent in the acyloxy group undergo symmetrization to aluminum tert-butylate.
- Stepovik,Kazakina,Martynova
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p. 1371 - 1377
(2007/10/03)
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- Migration of trimethylsilyl groups in enolates of silyl esters
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The lithium enolate of trimethylsilyl acetate (1) undergoes a 1,3-0 → C migration of the trimethylsilyl group.
- Hudrlik, Paul F.,Roberts, Ralph R.,Ma, Da,Hudrlik, Anne M.
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p. 4029 - 4032
(2007/10/03)
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- Process for carbapenem intermediates
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A novel intermediate for synthesizing 1 β-alkyl-1-carbapenem, i.e., 4 β-(1 β-alkyl-2-carboxyprop-2-enyl)azetidin-2-one (II), is prepared stereoselectively by treating 4-(leaving group substituted)azetidin-2-one (I) with trans-2-(leaving group substituted)-methyl-3-alkylacrylic acid (III) and a reducing metal. STR1 wherein R1 is hydrogen, alkyl, or substituted alkyl; R2 is optionally substituted alkyl; R3 is hydrogen or a carboxy-protecting group; and R4 and R5 each is a leaving group.
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