25104-37-4Relevant articles and documents
Phosphine-Catalyzed Vinylation at Low Acetylene Pressure
Bienewald, Frank,Comba, Peter,Hashmi, A. Stephen K.,Menche, Maximilian,Rominger, Frank,Schafer, Ansgar,Schaub, Thomas,Sitte, Nikolai A.,Tuzina, Pavel
, p. 13041 - 13055 (2021/09/18)
The vinylation of various nucleophiles with acetylene at a maximum pressure of 1.5 bar is achieved by organocatalysis with easily accessible phosphines like tri-n-butylphosphine. A detailed mechanistic investigation by quantum-chemical and experimental methods supports a nucleophilic activation of acetylene by the phosphine catalyst. At 140 °C and typically 5 mol % catalyst loading, cyclic amides, oxazolidinones, ureas, unsaturated cyclic amines, and alcohols were successfully vinylated. Furthermore, the in situ generation of a vinyl phosphonium species can also be utilized in Wittig-type functionalization of aldehydes.
Photosonoelectrochemical analysis of Lawsonia inermis (henna) and artificial dye used in tattoo and dye industry
Chandrakalavathi,Sudha,Sindhuja,Harinipriya,Jeyalakshmi
, p. 44 - 57 (2018/04/30)
Photosonoelectrochemical (PSEC) analysis of Lawsonia inermis, lawsone and ?-Phenylenediamine were investigated in ethanol to understand the degradation mechanism and harmful byproducts. To simulate the operating conditions of the tattoo ink, dye solutions
Decomposition of a Β-O-4 lignin model compound over solid Cs-substituted polyoxometalates in anhydrous ethanol: acidity or redox property dependence?
Wu, Xuezhong,Jiao, Wenqian,Li, Bing-Zheng,Li, Yanming,Zhang, Yahong,Wang, Quanrui,Tang, Yi
, p. 1216 - 1228 (2017/07/10)
Production of aromatics from lignin has attracted much attention. Because of the coexistence of C–O and C–C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for developing a lignin catalytic decomposition process could be developed by exploring the transformation mechanisms of various model compounds. Herein, decomposition of a lignin model compound, 2-phenoxyacetophenone (2-PAP), was investigated over several cesium-exchanged polyoxometalate (Cs-POM) catalysts. Decomposition of 2-PAP can follow two different mechanisms: an active hydrogen transfer mechanism or an oxonium cation mechanism. The mechanism for most reactions depends on the competition between the acidity and redox properties of the catalysts. The catalysts of POMs perform the following functions: promoting active hydrogen liberated from ethanol and causing formation of and then temporarily stabilizing oxonium cations from 2-PAP. The use of Cs-PMo, which with strong redox ability, enhances hydrogen liberation and promotes liberated hydrogen transfer to the reaction intermediates. As a consequence, complete conversion of 2-PAP (>99%) with excellent selectivities to the desired products (98.6% for phenol and 91.1% for acetophenone) can be achieved.
Iridium Pincer-Catalyzed Dehydrogenation of Ethers Featuring Ethylene as the Hydrogen Acceptor
Lyons, Thomas W.,Bzier, David,Brookhart, Maurice
, p. 4058 - 4062 (2015/09/01)
We describe efficient methods to dehydrogenate ethers by using iridium pincer complexes (iPr4Anthraphos)-Ir(H)(Cl), 4, iPr4PC(sp3)P-Ir(H)(Cl), 5, and (iPr4PCP)-Ir(H)(Cl), 6. At 120°C, cyclic ethers were dehydrogenated with tert-butylethylene as the hydrogen acceptor with high turnover numbers (over 400 in many cases). Acyclic ethers such as diethyl ether can also be dehydrogenated catalytically with TONs up to 90. The efficient dehydrogenation of cyclic and acyclic ethers using ethylene as a more practical hydrogen acceptor has been demonstrated for the first time. (Figure Presented)
Ruthenium-Catalyzed Olefin Cross-Metathesis with Tetrafluoroethylene and Analogous Fluoroolefins
Takahira, Yusuke,Morizawa, Yoshitomi
supporting information, p. 7031 - 7034 (2015/06/25)
This Communication describes a successful olefin cross-metathesis with tetrafluoroethylene and its analogues. A key to the efficient catalytic cycle is interconversion between two thermodynamically stable, generally considered sluggish, Fischer carbenes. This newly demonstrated catalytic transformation enables easy and short-step synthesis of a new class of partially fluorinated olefins bearing plural fluorine atoms, which are particularly important and valuable compounds in organic synthesis and medicinal chemistry as well as the materials and polymer industries.
Experimental and theoretical study of the 2-alkoxyethylidene rearrangement
Graves, Kimberly S.,Thamattoor, Dasan M.,Rablen, Paul R.
experimental part, p. 1584 - 1591 (2011/05/19)
The rearrangement of 2-ethoxyethylidene, generated photochemically from a nonnitrogenous precursor, leads to ethyl vinyl ether. Although this product could result, in principle, from a 1,2-hydrogen shift and/or a 1,2-ethoxy shift in the carbene, a deuterium labeling study indicates an essentially exclusive preference for hydrogen migration. The experimental results are in agreement with CCSD and W1BD calculations for the simpler 2-methoxyethylidene system that show a prohibitively large barrier for the methoxy shift and a negligible barrier for the hydride shift. 2011 American Chemical Society.
A Simple, effective boron-halide ethoxylation catalyst
Moloy, Kenneth G.
body text, p. 821 - 826 (2010/07/05)
Boron esters B(OR)3, readily derived from boric acid and alcohols, combine with iodide or bromide to catalyze the ethoxylation of alcohols and phenols, giving good rates and narrow product distributions. The combined action of a weak electrophile [B(OR)3] and a weak nucleophile (halide) allows for the ethoxylation of base-sensitive alcohols. Experiment suggests a new mechanism for this commercially important reaction proceeding through key β-haloalkoxy intermediates.
METHOD FOR PRODUCING , -UNSATURATED ETHER
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Page/Page column 9-12; 16-17, (2008/12/04)
Disclosed is a method for producing an α,β-unsaturated ether efficiently and stably for a long time. In the method for producing an α,β-unsaturated ether, an acetal is thermally decomposed in the presence of a catalyst containing an apatite represented by any of the following formulae (1)-(4). ????????(M)5-y(HZO4)y(ZO4)3-y(X)1-y?????(1) ????????(M)5-y(HPO4)y(PO4)3-y(X)1-y?????(2) ????????(M)5-y+2n(HZO4)y(ZO4)3-y(X)1-y(SiO4)n?????(3) ????????(M)5-y+m(HZO4)y(ZO4)3-y(X)1-y(CO3)m?????(4)
Process and catalysts for the oxidation of methanol and/or ethanol
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Page/Page column 7, (2008/06/13)
A process for oxidation of methanol, ethanol, or a mixture of methanol and ethanol comprising contacting the methanol and/or ethanol with an oxygen-containing gas and a supported catalyst comprising one or more platinum group oxides. The process conditions and/or catalyst may be selected to as to selectively produce methyl formate from methanol or diethoxyethane from ethanol. The invention also includes certain novel supported platinum group metal oxide catalysts. Preferred catalysts include one or more ruthenium oxides.
New fluoromonomers and methods of production, and new fluoropolymers produced therefrom
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, (2008/06/13)
The present invention provides new fluoromonomers having the generic structure: CF2═CF(OCH2CH2)nOR where n is an integer and R is a functional group and methods for producing same. A new method of synthesizing the fluoromonomers is provided. The present invention also relates to new fluoropolymers prepared from any one or combination of the new fluoromonomers and having the generic structure: —[—CF2CF{(OCH2CH2)nOR}—]m— where n is an integer, m is an integer and R represents an unsubstituted or inertly substituted hydrocarbyl group. The method also relates to new copolymers or terpolymers prepared from the new fluoromonomers alone, the new fluoromonomers and existing fluoromonomers or the new fluoromonomers and existing hydrocarbon or functionalized hydrocarbon monomers.
