623-91-6Relevant articles and documents
Hydration of Diethyl Maleate in the Presence of Bimetallic Hydroxy Palladium(II) Complexes of 1,2-Bis(diphenylphosphino)ethane(dppe) as Catalysts
Ganguly, Sanjoy,Roundhill, D. Max
, p. 639 - 640 (1991)
The hydration of diethyl maleate is catalysed by the presemce of 2(BF4)2 in solution.
Thiyl radical induced isomerisations of maleate esters provide a convenient route to fumarates and furanones
Harrowven, David C.,Hannam, Joanne C.
, p. 9341 - 9346 (1999)
Maleate esters can be converted into fumarate esters in near quantitative yield through exposure to thiyl radicals generated in refluxing hexane by photolysis of diphenyl disulfide. When conditions are applied to dialkyl (hydroxyalkyl)maleate esters akin to 3, 2(5H)-furanones are given in good yield.
Bottom-Up Synthesis of Acrylic and Styrylic RhII Carboxylate Polymer Beads: Solid-Supported Analogs of Rh2(OAc)4
Levchenko, Vladimir,Sundsli, B?rd,?ien-?degaard, Sigurd,Tilset, Mats,Hansen, Finn K.,Bonge-Hansen, Tore
, p. 6150 - 6157 (2018)
We have developed a short and efficient bottom-up synthesis of acrylic and styrylic polymer beads containing dirhodium(II) tetracarboxylates. The solid supported dirhodium(II) tetracarboxylate catalysts were synthesized in as little as two steps overall from dirhodium tetratrifluoroacetate and commercially available carboxylic acids, making the bottom-up approach a viable alternative to the post-modification approach commonly used. The dirhodium(II) tetracarboxylate polymer beads have a convenient size (ca. 100 μm), are easy to handle, and can be considered solid-supported analogs of Rh2(OAc)4. Beads generated from dirhodium(II) tetracarboxylates with four polymerizable carboxylate ligands displayed the best catalytic performance and compared favorably to Rh2(OAc)4 in benchmarked cyclopropanation reactions. The results imply that the cumbersome synthesis of monomeric dirhodium(II) tetracarboxylates with mixed ligands systems can be avoided and that immobilized dirhodium(II)-catalysts with a higher degree of crosslinking is a viable option to catalysts linked in an anchor-like fashion. We demonstrate recovery and recycling, and a potential use of the beads as catalysts in a cyclopropanation reaction towards the insecticide chrysanthemic acid.
Synthesis of 17-epi-calcitriol from a common androstane derivative, involving the ring B photochemical opening and the intermediate triene ozonolysis
Kurek-Tyrlik, Alicja,Michalak, Karol,Wicha, Jerzy
, p. 8513 - 8521 (2005)
An efficient synthesis of 17-epi-calcitriol 2, an epimer of natural hormone, via 17-epi-cholesterol 5a is described. Synthesis of 5a includes palladium-catalyzed cyclopropanation of the common androstane derivative 7 with an alkyl diazoacetate, reductive fission of the less shielded side of cyclopropane carboxylic acid esters 6, oxidation of the products into acid 11a, and alkylation of ester 11b. Photolysis of 7,8-dedydro-17-epi-25- hydroxycholesterol 19b and consecutive thermal rearrangement gave a mixture of several products that was subjected to ozonolysis to provide, after chromatography, hydroxy ketone 3a. The silyl derivative 3b was coupled with the respective ring A building block.
Phosphine-Catalyzed Cycloaddition of 2,3-Butadienoates or 2-Butynoates with Electron-Deficient Olefins. A Novel Annulation Approach to Cyclopentenes
Zhang, Chunming,Lu, Xiyan
, p. 2906 - 2908 (1995)
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One-pot production of diethyl maleate via catalytic conversion of raw lignocellulosic biomass
Cai, Zhenping,Chen, Rujia,Jiang, Lilong,Li, Fukun,Li, Xuehui,Long, Jinxing,Zhang, Hao
supporting information, p. 10116 - 10122 (2021/12/24)
The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g-1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment.
Mechanochemical defect engineering of HKUST-1 and impact of the resulting defects on carbon dioxide sorption and catalytic cyclopropanation
Barozzino-Consiglio, Gabriella,Filinchuk, Yaroslav,Grégoire, Nicolas,Hermans, Sophie,Steenhaut, Timothy
, p. 19822 - 19831 (2020/06/03)
Metal-organic frameworks (MOFs) are recognized as ideal candidates for many applications such as gas sorption and catalysis. For a long time the properties of these materials were thought to essentially arise from their well-defined crystal structures. It is only recently that the importance of structural defects for the properties of MOFs has been evidenced. In this work, salt-assisted and liquid-assisted grinding were used to introduce defects in a copper-based MOF, namely HKUST-1. Different milling times and post-synthetic treatments with alcohols allow introduction of defects in the form of free carboxylic acid groups or reduced copper(i) sites. The nature and the amount of defects were evaluated by spectroscopic methods (FTIR, XPS) as well as TGA and NH3temperature-programmed desorption experiments. The negative impact of free -COOH groups on the catalytic cyclopropanation reaction of ethyl diazoacetate with styrene, as well as on the gravimetric CO2sorption capacities of the materials, was demonstrated. The improvement of the catalytic activity of carboxylic acid containing materials by the presence of CuIsites was also evidenced.
