- One-pot production of diethyl maleate via catalytic conversion of raw lignocellulosic biomass
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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.
- Cai, Zhenping,Chen, Rujia,Zhang, Hao,Li, Fukun,Long, Jinxing,Jiang, Lilong,Li, Xuehui
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supporting information
p. 10116 - 10122
(2021/12/24)
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- Sulfonamide compound and medical applications thereof
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The invention discloses a compound containing a sulfonamide structure, a preparation method thereof, and medical applications of the compound, and more specifically discloses the compound with a structure represented by formula I, and a pharmaceutically acceptable salt or a prodrug or a solvate thereof. The compound is used for tumor treatment through inhibiting ATP-citrate lyase.
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Paragraph 0056-0059
(2019/02/13)
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- Continuous Flow Synthesis under High-Temperature/High-Pressure Conditions Using a Resistively Heated Flow Reactor
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A cheap, easy-to-build, and effective resistively heated reactor for continuous flow synthesis at high temperature and pressure is herein presented. The reactor is rapidly heated directly using an electric current and is capable of rapidly delivering temperatures and pressures up to 400 °C and 200 bar, respectively. High-temperature and high-pressure applications of this reactor were safely performed and demonstrated by selected transformations such as esterifications, transesterifications, and direct carboxylic acid to nitrile reactions using supercritical ethanol, methanol, and acetonitrile. Reaction temperatures were between 300 and 400 °C with excellent conversions and good to excellent isolated product yields. Examples of Diels-Alder reactions were also carried out at temperatures up to 300 °C in high yield. No additives or catalysts were used in the reactions.
- Adeyemi, Ahmed,Bergman, Joakim,Br?nalt, Jonas,S?vmarker, Jonas,Larhed, Mats
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supporting information
p. 947 - 955
(2017/07/26)
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- Synthesis of C3-substituted enantiopure 2-(p-tolylsulfinyl)-furans: The sulfoxide group as a chiral inductor for furan dienes as precursors of a wide variety of chiral intermediates
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(-)-(1R,2S,5R)-Menthyl (SS)-p-toluenesulfinate and its enantiomer are a common source for a chiral sulfoxide group in organic synthesis, by means of nucleophilic substitution. The replacement of the menthyloxy group, with complete inversion of configuration at the sulfur center of the chiral sulfoxide, allows the inclusion of this organic function into numerous substrates, with defined stereochemistry and high enantiomeric purity. Nine C3-substituted, enantiomerically pure, 2-sulfinylfurans were prepared by this synthetic methodology with moderate to high yields. These enantiopure C3-substituted 2-sulfinylfurans can be used as chiral dienes for [4+3] cycloaddition reactions and in other chemical transformations, in which π-facial selectivity should be induced in order to obtain enantioselective reactions.
- Montana, Angel M.,Grima, Pedro M.,Batalla, Consuelo,Kociok-Koehn, Gabriele
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p. 677 - 689
(2014/05/20)
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- Cycloaddition of C-3 substituted furans. Stereoselectivity induced by coordination effects
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Several C-3 substituted furans with chelating groups have been reacted with 2,3-dibromo-3-pentanone in the presence of a reducing metal, resulting in the formation of [4+3]-cycloadducts with complete cis-trans and endo-exo diastereoselectivity and in excellent yield. A certain variability of the conversion and reaction yield could be observed, when changing the reaction conditions, but in all cases the stereoselectivity was complete, compared to that of C-3 substituted furans with non-chelating groups. Also, a general method of assignment of stereochemistry of cycloadducts has been established by NMR, considering diagnostic patterns of signals with different multiplicity and chemical shifts depending on the stereochemistry of diastereomeric cycloadducts.
- Montana, Angel M.,Castellvi, Maria,Batalla, Consuelo,Grima, Pedro M.,Font-Bardia, Merce
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p. 9982 - 9998,17
(2012/12/12)
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- Cycloaddition of C-3 substituted furans. Stereoselectivity induced by coordination effects
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Several C-3 substituted furans with chelating groups have been reacted with 2,3-dibromo-3-pentanone in the presence of a reducing metal, resulting in the formation of [4+3]-cycloadducts with complete cis-trans and endo-exo diastereoselectivity and in excellent yield. A certain variability of the conversion and reaction yield could be observed, when changing the reaction conditions, but in all cases the stereoselectivity was complete, compared to that of C-3 substituted furans with non-chelating groups. Also, a general method of assignment of stereochemistry of cycloadducts has been established by NMR, considering diagnostic patterns of signals with different multiplicity and chemical shifts depending on the stereochemistry of diastereomeric cycloadducts.
- Monta?a, ángel M.,Grima, Pedro M.,Castellví, María,Batalla, Consuelo,Font-Bardia, Mercè
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p. 9982 - 9998
(2013/01/14)
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- Convenient synthesis of furan-3-carboxylic acid and derivatives
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A convenient synthesis of furan-3-carboxylic acid and derivatives from aromatization of 4-trichloroacetyl-2,3-dihydrofuran followed by nucleophilic displacement of the trichloromethyl group by hydroxide, alcohols, and amines, is presented.
- Zanatta, Nilo,Faoro, Débora,Silva, Simone C.,Bonacorso, Helio G.,Martins, Marcos A.P.
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p. 5689 - 5691
(2007/10/03)
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- Investigation of methods for seven-membered ring synthesis: A practical synthesis of 4-oxo-5,6,7,8-tetrahydro-4h-cyclohepta[b]furan-3-carboxylic acid
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Several synthetic routes to 4-oxo-5,6,7,8-tetrahydro-4H-cyclohepta[b]furan-3-carboxylic acid (1) are described, and the scale-up issues with each route are discussed. Seven-membered ring formation is a key issue with these syntheses, and several strategies are presented, including preparation from cycloheptane-1,3-dione, ring-expansion routes, Dieckmann cyclization, acetylene-furan [4 + 2] cycloaddition, and Friedel-Crafts cyclization. Two of the routes were scaled in the pilot plant to provide kilogram quantities of the title compound. The first scale-up route is outlined in Scheme 2 and utilizes a ring-expansion strategy to prepare cycloheptane-1,3-dione from cyclopentanone, via a [2 + 2] cycloaddition between dichloroketene and the silyl enol ether of cyclopentanone. The diketone is converted to the title compound by condensation with ethyl bromopyruvate and base, followed by acid hydrolysis. This route was efficient on laboratory scale but encountered problems upon scale-up due to a competing fragmentation pathway in the Zn/AcOH-mediated retro-aldol of cyclobutanone 11. The second, more successful scale-up route is described in Scheme 15, and involves Friedel-Crafts acylation of 3-carboethoxyfuran selectively at the 5-position. Reduction, lactonization, and hydrogenolysis provide acid 43, which is cyclized via a second Friedel-Crafts reaction to form the seven-membered ketone.
- Ragan, John A.,Murry, Jerry A.,Castaldi, Michael J.,Conrad, Alyson K.,Jones, Brian P.,Bryan, Li,Makowski, Teresa W.,McDermott, Ruth,Sitter, Barb J.,White, Timothy D.,Young, Gregory R.
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p. 498 - 507
(2013/09/07)
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- Substituted heterocyclylisoquinolinium salts and compositions and method of use thereof
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Substitutued heterocyclylisoquinolinium salts, pharmaceutical compositions containing them and methods for the treatment or prevention of neurodegenerative disorders or neurotoxic injuries utilizing them.
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- Substituted 6,11-ethano-6,11-dihydrobenzo[b] quinolizinium salts and compositions and methods of use thereof
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Substituted 6,11-ethano-6,11-dihydrobenzo[b]quinolizinium salts, pharmaceutical compositions containing them, and methods for the treatment of neurodegenerative disorders or neurotoxic injuries utilizing them, wherein the substituted 6,11-ethano-6,11-dihydrobenzo[b]quinolizinium salts have the formula: STR1 wherein: R1, R2, R3, R4, R5, R6, R7, X and p are as defined in the specification.
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- SYNTHESIS OF 3-ACYL AND 3-CARBOALKOXYFURANS BY THE CERIC AMMONIUM NITRATE PROMOTED ADDITION OF 1,3-DICARBONYL COMPOUNDS TO VINYLIC ACETATES
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3-Acyl- and 3-carboalkoxyfurans can be prepared in 30-55percent yield by the oxidative addition of 1,3-dicarbonyl compounds to vinylic acetates induced by ceric ammonium nitrate.
- Baciocchi, Enrico,Ruzziconi, Renzo
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p. 1841 - 1846
(2007/10/02)
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- Isomerization and Fragmentation of Methylfuran Ions and Pyran Ions in the Gas Phase
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The mutual interconversion of the molecular ions +. of 2-methylfuran (1), 3-methylfuran (2) and 4H-pyran (3) before fragmentation to + ions has been studied by collisional activation spectrometry, by deuterium labelling, by the kinetic energy release during the fragmentation, by appearance energies and by a MNDO calculation of the minimum energy reaction path.The electron impact and collisional activation mass spectra show clearly that the molecular ions of 1-3 do not equilibrate prior to fragmentation, but that mostly pyrylium ions + arise by the loss of a H atom.This implies an irreversible isomerization of methylfuran ions 1 and 2 into pyran ions before fragmentation, in contrast to the isomerization of the related systems toluene ions/cycloheptatriene ions.Complete H/D scrambling is observed in deuterated methylfuran ions prior to the H/D loss that is associated with an isotope effect kH/kD=1.67-2.16 for metastable ions.In contrast, no H/D scrambling has been observed in deuterated 4H-pyran ions.However, the loss of a H atom from all metastable +. ions gives rise to a flat-topped peak in the mass-analysed ion kinetic energy spectrum and a kinetic energy release (T50) of 26+/-1.5 kJ mol-1.The MNDO calculation of the minimum energy reaction path reveals that methylfuran ions 1+. and 2+. favour a rearrangement into pyran ions before fragmentation into furfuryl ions, but that the energy barrier of the first rearrangement step is at least of the same height as the barrier for the dissociation of pyran ions into pyrylium ions.This agrees with the experimental results.
- Spilker, Ruediger,Gruetzmacher, H.-F.
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p. 459 - 466
(2007/10/02)
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- A SIMPLE SYNTHESIS OF 3-SUBSTITUTED FURANS. THE PREPARATIONS OF DENDROLASIN, PERILLENE AND CONGENERS
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The Grignard reagent 7, derived from 3-chloromethyl furan, reacts with various alkyl- and allylic halides, in the presence of Li2CuCl4, to provide high yields of 3-substituted furans.
- Tanis, Steven P.
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p. 3115 - 3118
(2007/10/02)
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- Imidazo [2,1-a]isoquinolines
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Imidazo[2,1-a]isoquinolines useful as anorexics and anti-depressants, e.g. 5-(2-thienyl)-2,3,5,6-tetrahydroimidazo[2,1-a]isoquinolin-5-ol, are prepared from a dilithium derivative of a 2-(o-tolyl)-2-imidazoline.
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