1487-18-9Relevant academic research and scientific papers
Ba(OH)2 as Catalyst in Organic Reactions. 20. Structure-Catalytic Activity Relationship in the Wittig Reaction
Climent, M. S.,Marinas, J. M.,Mouloungui, Z.,Bigot, Y. Le,Delmas, M.,et al.
, p. 3695 - 3701 (1989)
Three barium hydroxide catalysts with different surface-area values and amounts of basic and reducing sites are used as catalysts in the Wittig reactions.These catalysts have different microcrystalline structures and therefore different geometrical properties in the active sites, that govern the adsorption of the reagents on the solid surface.Several phosphonium salts (Ph3P+CH2R; R = H, CH2CH2CH3, CO2Et, and COPh) with different pKa, geometrical, and electronic characteristic have been used.The structure-catalytic activity relationship is analyzed.The most active catalyst, C-200, is less active in the Wittig reaction than in the Wittig-Horner reaction.This fact is explained by geometrical reasons.The process takes place in the homogeneous phase with phosphonium salts of a strong acid character (R = CO2Et, COPh) that lead to stable yields.The weak acids (R = H, CH3CH2CH2) lead to reaction products in the heterogeneous solid-liquid conditions.The cell lattice of the solid governs the process that is carried out in the heterogeneous phase.The process with the strongest acid (R = COPh, pKa = 6.0) is not governed by the cell lattice because this acid can react to any kind of basis site in the solid.The reaction with R = CO2Et (pKa = 8.8) is carried out in the homogeneous phase because the ylide is stable.However, the formation of the ylide is controlled by the cell lattice because basic sites with pKa > 8.8 and adequate geometry are necessary to produce the ylide on the solid surface.
SYNTHESIS OF (2-FURYL)-β-ALKYLACETALDEHYDES BY THE HYDROFORMYLATION OF 2-ALKENYLFURANS
Lapidus, A. L.,Rodin, A. P.,Pruidze, I. G.,Ugrak, B. I.
, p. 1509 - 1511 (1990)
A study was carried out on the hydroformylation of 2-vinyl-, and 2-propenylfurans in the presence of HRh(CO)(PPh3)3 as a homogeneous catalyst.The substrate/catalyst mole ratio was 600.Gas-liquid chromatography, PMR, and 13C NMR spectroscopy were used to establish that the reaction proceeds regioselectively in the case of 2-vinylfuran and regiospecifically in the case of 2-propenylfuran.
On the valence shell electronic spectroscopy of 2-vinyl furan
Giuliani,Walker,Delwiche,Hoffmann,Kech,Limao-Vieira,Mason,Hubin-Franskin
, p. 10972 - 10982 (2004)
The vacuum ultraviolet (VUV) absorption spectra of 2-vinyl furan was investigated. The spectroscopic properties of the 2-vinyl furan was analyzed using electron energy loss spectroscopy and synchrotron radiation source with absolute cross section determinations. The semiempirical molecular orbital calculations was used for the interpretation of the HeI photoelectron spectrum. A photoabsorption spectrum was observed in the first band in the UV absorption spectra in solution of furans in position 2 of polyenyl groups of increasing size.
Br?nsted Acid Catalyzed Peterson Olefinations
Britten, Thomas K.,McLaughlin, Mark G.
, p. 301 - 305 (2020)
A mild and facile Peterson olefination has been developed employing low catalyst loading of the Br?nsted acid HNTf2. The reactions are typically performed at room temperature, with the reaction tolerant to a range of useful functionalities. Furthermore, we have extended this methodology to the synthesis of enynes.
Method for synthesizing biomass-based functional monomer based on furfuryl alcohol/methanol catalytic conversion and catalyst application
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Paragraph 0121-0144, (2021/04/17)
The invention provides an application of a solid catalyst in synthesis of a furylethylene functional monomer and a method for synthesizing a biomass-based functional monomer based on furfuryl alcohol/methanol catalytic conversion. The invention provides the application of the solid catalyst in the synthesis of the furylethylene functional monomer for the first time. Cheap and easily available bulk chemical furfuryl alcohol and derivatives thereof and methanol are used as raw materials, and the biomass-based functional monomer is synthesized on solid catalysts such as a molecular sieve and a modified molecular sieve catalyst by a gas-phase one-step method. The functional monomer has the characteristics that a furan group and a carbon-carbon double bond are contained in the structure, the synthesis method has the characteristics of a methanol-to-olefin industrial technology, the operation is simple, the flow is short, harsh experimental conditions are not needed, the cost of raw materials and a catalyst is low, the preparation is easy, and the defects of a conventional synthesis strategy based on a Witting reaction are broken through. The invention provides a green and sustainable new strategy for synthesizing the furylethylene functional monomer, and the method has a good industrial prospect.
A Systems Approach to a One-Pot Electrochemical Wittig Olefination Avoiding the Use of Chemical Reductant or Sacrificial Electrode
Chakraborty, Biswarup,Kostenko, Arseni,Menezes, Prashanth W.,Driess, Matthias
supporting information, p. 11829 - 11834 (2020/08/19)
An unprecedented one-pot fully electrochemically driven Wittig olefination reaction system without employing a chemical reductant or sacrificial electrode material to regenerate triphenylphosphine (TPP) from triphenylphosphine oxide (TPPO) and base-free in situ formation of Wittig ylides, is reported. Starting from TPPO, the initial step of the phosphoryl P=O bond activation proceeds through alkylation with RX (R=Me, Et; X=OSO2CF3 (OTf)), affording the corresponding [Ph3POR]+X? salts which undergo efficient electroreduction to TPP in the presence of a substoichiometric amount of the Sc(OTf)3 Lewis acid on a Ag-electrode. Subsequent alkylation of TPP affords Ph3PR+ which enables a facile and efficient electrochemical in situ formation of the corresponding Wittig ylide under base-free condition and their direct use for the olefination of various carbonyl compounds. The mechanism and, in particular, the intriguing role of Sc3+ as mediator in the TPPO electroreduction been uncovered by density functional theory calculations.
N,N,O-Coordinated tricarbonylrhenium precatalysts for the aerobic deoxydehydration of diols and polyols
Klein Gebbink, Robertus J. M.,Li, Jing,Lutz, Martin
, p. 3782 - 3788 (2020/06/22)
Rhenium complexes are well known catalysts for the deoxydehydration (DODH) of vicinal diols (glycols). In this work, we report on the DODH of diols and biomass-derived polyols using L4Re(CO)3as precatalyst (L4Re(CO)3= tricarbonylrhenium 2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)(methyl)amino)methyl)phenolate). The DODH reaction was optimized using 2 mol% of L4Re(CO)3as precatalyst and 3-octanol as both reductant and solvent under aerobic conditions, generating the active high-valent rhenium speciesin situ. Both diol and biomass-based polyol substrates could be applied in this system to form the corresponding olefins with moderate to high yield. Typical features of this aerobic DODH system include a low tendency for the isomerization of aliphatic external olefin products to internal olefins, a high butadiene selectivity in the DODH of erythritol, the preferential formation of 2-vinylfuran from sugar substrates, and an overall low precatalyst loading. Several of these features indicate the formation of an active species that is different from the species formed in DODH by rhenium-trioxo catalysts. Overall, the bench-top stable and synthetically easily accessible, low-valent NNO-rhenium complex L4Re(CO)3represents an interesting alternative to high-valent rhenium catalysts in DODH chemistry.
Synthetic Entry to Polyfunctionalized Molecules through the [3+2]-Cycloaddition of Thiocarbonyl Ylides
Habiger, Christoph,Haut, Franz-Lucas,Korber, Johannes Nepomuk,Müller, Thomas,Magauer, Thomas,Mayer, Peter,Speck, Klaus,Wurst, Klaus
supporting information, (2019/09/06)
Here we present a comprehensive study on the [3+2]-cycloaddition of thiocarbonyl ylides with a wide variety of alkenes and alkynes. The obtained dihydro- and tetrahydrothiophene products serve as exceptionally versatile intermediates providing access to thiophenes, dienes, dendralenes, and vic-quarternary carbon centers. The use of high-pressure conditions enables thermally unstable, sterically encumbered or moderately reactive substrates to undergo the cycloaddition under mild conditions, thereby increasing the yield by up to 58percent. In addition, we showcase its utility by the formal syntheses of the pharmaceuticals NGB 4420 and tenilapine.
Efficient and Practical Transfer Hydrogenation of Ketones Catalyzed by a Simple Bidentate Mn?NHC Complex
van Putten, Robbert,Benschop, Joeri,de Munck, Vincent J.,Weber, Manuela,Müller, Christian,Filonenko, Georgy A.,Pidko, Evgeny A.
, p. 5232 - 5235 (2019/07/18)
Catalytic reductions of carbonyl-containing compounds are highly important for the safe, sustainable, and economical production of alcohols. Herein, we report on the efficient transfer hydrogenation of ketones catalyzed by a highly potent Mn(I)?NHC complex. Mn?NHC 1 is practical at metal concentrations as low as 75 ppm, thus approaching loadings more conventionally reserved for noble metal based systems. With these low Mn concentrations, catalyst deactivation is found to be highly temperature dependent and becomes especially prominent at increased reaction temperature. Ultimately, understanding of deactivation pathways could help close the activity/stability-gap with Ru and Ir catalysts towards the practical implementation of sustainable earth-abundant Mn-complexes.
Terminal Alkenes from Acrylic Acid Derivatives via Non-Oxidative Enzymatic Decarboxylation by Ferulic Acid Decarboxylases
Aleku, Godwin A.,Prause, Christoph,Bradshaw-Allen, Ruth T.,Plasch, Katharina,Glueck, Silvia M.,Bailey, Samuel S.,Payne, Karl A. P.,Parker, David A.,Faber, Kurt,Leys, David
, p. 3736 - 3745 (2018/08/03)
Fungal ferulic acid decarboxylases (FDCs) belong to the UbiD-family of enzymes and catalyse the reversible (de)carboxylation of cinnamic acid derivatives through the use of a prenylated flavin cofactor. The latter is synthesised by the flavin prenyltransferase UbiX. Herein, we demonstrate the applicability of FDC/UbiX expressing cells for both isolated enzyme and whole-cell biocatalysis. FDCs exhibit high activity with total turnover numbers (TTN) of up to 55000 and turnover frequency (TOF) of up to 370 min?1. Co-solvent compatibility studies revealed FDC's tolerance to some organic solvents up 20 % v/v. Using the in-vitro (de)carboxylase activity of holo-FDC as well as whole-cell biocatalysts, we performed a substrate profiling study of three FDCs, providing insights into structural determinants of activity. FDCs display broad substrate tolerance towards a wide range of acrylic acid derivatives bearing (hetero)cyclic or olefinic substituents at C3 affording conversions of up to >99 %. The synthetic utility of FDCs was demonstrated by a preparative-scale decarboxylation.
