15486-24-5Relevant academic research and scientific papers
Novel nor-harmal alkaloid from Adhatoda vasica
Jain,Koul,Dhar,Atal
, p. 1880 - 1882 (1980)
A novel alkaloid and a galactoside isolated from the roots of Adhatoda vasica have been characterized as 9-acetamido-3,4-dihydropyrido-(3,4-b)-indole and O-ethyl-α-D-galactoside respectively by chemical and spectroscopic methods. In addition sitosterol β-D-glucoside, D-galactose and deoxyvasicinone have also been isolated from the roots of this plant.
Ethanolysis of selected catalysis by functionalized acidic ionic liquids: An unexpected effect of ILs structural functionalization on selectivity phenomena
Nowakowska-Bogdan, Ewa,Nowicki, Janusz
, p. 1857 - 1866 (2022/02/05)
A series of functionalized hydrogen sulfate imidazolium ILs were synthesized and applied as catalysts in the reaction of glucose, xylose and fructose with ethanol. In this research, an unexpected selectivity phenomenon was observed. It showed that in this reaction functionalized ILs should be considered as a special type of catalyst. Functionalization of alkyl imidazolium ILs, especially the addition of electronegative OH groups, causes a clear and unexpected effect manifested via visible changes in the selectivity of the reaction studied. In the case of fructose, an increase in the number of OH groups affects an increase in the selectivity towards ethyl levulinate from 14.2% for [bmim]HSO4 to 20.1% for [glymim]HSO4 with an additional increase in selectivity to 5-hydroxymethyfurfural. In turn, for xylose, the introduction of OH groups to the alkyl chain was manifested by a decrease in selectivity to furfural as its ethyl acetal and an increase in selectivity to ethylxylosides. This journal is
Bio-based Surfactants
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, (2022/03/31)
Bio-based surfactants have great opportunity for use in a variety of applications such as laundry detergents, industrial cleaners, adjuvants, and oil and gas. Surfactants in these applications can be nonionic, anionic, cationic, or amphoteric. Utilizing high oleic soybean oil as a platform chemical, a variety of surfactants and properties can be produced. While early work focused solely on surfactant use in laundry cleaning and fracking, recent work has expanded functional groups and application evaluations in hard surface cleaning. The current invention expands on Battelle's high oleic soybean oil (HOSO) surfactant technology. Use of HOSO overcomes the limitations of regular soybean oil and significantly reduces or eliminates undesirable byproducts in most chemistries. However, with use of select reagents, a few candidates were achievable with regular epoxidized soybean oil (ESO). The HOSO surfactant platform offers several key advantages including: a highly water miscible (not typical of C18 surfactants) and water stable surfactant; ability to adjust and vary hydrophilic-lipophilic (HLB) values for stain removal performance; and increased biodegradability without toxic or persistent by-products.
Applications of Shoda's reagent (DMC) and analogues for activation of the anomeric centre of unprotected carbohydrates
Fairbanks, Antony J.
, (2020/12/07)
2-Chloro-1,3-dimethylimidazolinium chloride (DMC, herein also referred to as Shoda's reagent) and its derivatives are useful for numerous synthetic transformations in which the anomeric centre of unprotected reducing sugars is selectively activated in aqueous solution. As such unprotected sugars can undergo anomeric substitution with a range of added nucleophiles, providing highly efficient routes to a range of glycosides and glycoconjugates without the need for traditional protecting group manipulations. This mini-review summarizes the development of DMC and some of its derivatives/analogues, and highlights recent applications for protecting group-free synthesis.
Synthesis of alkyl α- and β-d-glucopyranoside-based chiral crown ethers and their application as enantioselective phase-transfer catalysts
Pálv?lgyi, ádám,Rapi, Zsolt,Ozohanics, Olivér,Tóth, Gábor,Keglevich, Gy?rgy,Bakó, Péter
, p. 1627 - 1645 (2017/11/16)
Chiral monoaza-15-crown-5-type lariat ethers annelated to alkyl 4,6-O-benzylidene-α- and β-d-glucopyranosides have been synthesized. These macrocycles generated significant asymmetric induction as phase-transfer catalysts in a few two-phase reactions. The catalytic effect of the lariat ethers with methoxy, ethoxy, and i-propoxy substituents on C-1 of the sugar unit in both α and β positions was compared. In liquid–liquid two-phase reactions, the nature and position of the substituents did not have much effect. The α-anomers were somewhat more efficient in terms of enantioselectivity than the β forms. In asymmetric Darzens condensations, in the epoxidation of trans-chalcone, in the Michael addition of β-nitrostyrene and diethyl acetamidomalonate, and in the reaction of 2-benzylidene-1,3-indandione with diethyl bromomalonate, maximum enantioselectivities of 73, 94, 78, and 72%, respectively, were obtained in presence of glucopyranoside-based lariat ethers as catalysts.
Glycosyl Bunte Salts: A Class of Intermediates for Sugar Chemistry
Meguro, Yasuhiro,Noguchi, Masato,Li, Gefei,Shoda, Shin-Ichiro
supporting information, p. 76 - 79 (2018/01/17)
S-Glycosyl thiosulfates have been discovered as a new class of synthetic intermediates in sugar chemistry, named "glycosyl Bunte salts" after 19th-century German chemist, Hans Bunte. The synthesis was achieved by direct condensation of unprotected sugars and sodium thiosulfate using a formamidine-type dehydrating agent in water-acetonitrile mixed solvent. The application of glycosyl Bunte salts is demonstrated with transformation reactions into other glycosyl compounds such as a 1-thio sugar, a glycosyl disulfide, a 1,6-anhydro sugar, and an O-glycoside.
Design of Ordered Mesoporous Sulfonic Acid Functionalized ZrO2/organosilica Bifunctional Catalysts for Direct Catalytic Conversion of Glucose to Ethyl Levulinate
Song, Daiyu,Zhang, Qingqing,Sun, Yingnan,Zhang, Panpan,Guo, Yi-Hang,Hu, Jiang-Lei
, p. 4967 - 4979 (2018/10/02)
Ordered mesoporous sulfonic acid functionalized ZrO2/organosilica catalysts (SO42?/ZrO2-PMO-SO3H) bearing tunable Br?nsted, and Lewis acid site distributions were prepared by a P123-directed sol-gel co-condensation route followed by ClSO3H functionalization. As-prepared catalysts were applied in the conversion of glucose to ethyl levulinate in ethanol medium. The SO42?/ZrO2-PMO-SO3H-catalyzed target reaction followed a glucose-ethyl glucoside-ethyl fructoside-5-ethoxymethylfurfural-ethyl levulinate pathway dominated by the synergistic effect of the super strong Br?nsted acidity, and moderate Lewis acidity of the catalysts. Additionally, by combining the advantages of the considerably high Br?nsted (696 μeq g?1), Lewis acid site density (703 μeq g?1), optimal Br?nsted/Lewis molar ratio (0.99), and excellent porosity properties, the SO42?/ZrO2-PMO-SO3H1.0 obtained at an initial Si/Zr molar ratio of 1.0 exhibited the highest ethyl levulinate yield (42.3 %) among the various tested catalysts. Moreover, the SO42?/ZrO2-PMO-SO3H can be reused three times without obvious changes in activity, morphology, and chemical structure.
Supported Tetrahedral Oxo-Sn Catalyst: Single Site, Two Modes of Catalysis
Beletskiy, Evgeny V.,Hou, Xianliang,Shen, Zhongliang,Gallagher, James R.,Miller, Jeffrey T.,Wu, Yuyang,Li, Tiehu,Kung, Mayfair C.,Kung, Harold H.
supporting information, p. 4294 - 4297 (2016/05/09)
Mild calcination in ozone of a (POSS)-Sn-(POSS) complex grafted on silica generated a heterogenized catalyst that mostly retained the tetrahedral coordination of its homogeneous precursor, as evidenced by spectroscopic characterizations using EXAFS, NMR, UV-vis, and DRIFT. The Sn centers are accessible and uniform and can be quantified by stoichiometric pyridine poisoning. This Sn-catalyst is active in hydride transfer reactions as a typical solid Lewis acid. However, the Sn centers can also create Br?nsted acidity with alcohol by binding the alcohol strongly as alkoxide and transferring the hydroxyl H to the neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions.
Direct catalytic transformation of biomass derivatives into biofuel component γ-valerolactone with magnetic nickel-zirconium nanoparticles
Li, Hu,Fang, Zhen,Yang, Song
, p. 135 - 142 (2016/02/05)
A series of mixed oxide nanoparticles were prepared by a coprecipitation method and characterized by many techniques. Nickel-zirconium oxide catalysts and their partially reduced magnetic counterparts were highly efficient in the direct transformation of biomass derivatives, including ethyl levulinate, fructose, glucose, cellobiose, and carboxymethyl cellulose, into γ-valerolactone (GVL) without the use of an external hydrogen source, producing a maximum GVL yield of 95.2 % at 200 °C for 3 h with hydrogen-reduced magnetic Zr5Ni5 nanoparticles (-1 h-1). Moreover, the magnetic Zr5Ni5 nanoparticles were conveniently recovered by means of a magnet for five cycles with almost constant activity. Attractive separation: Acid-base bifunctional NiZr nanocatalysts with strong magnetism show high activity and reusability in the transformation of biomass derivatives, including EL, fructose, glucose, cellobiose, and carboxymethyl cellulose, into γ-valerolactone (GVL) with 95.2 % yield and 98 % selectivity (see figure).
Metal-catalyzed stereoselective and protecting-group-free synthesis of 1,2-cis-glycosides using 4,6-dimethoxy-1,3,5-triazin-2-yl glycosides as glycosyl donors
Tanaka, Tomonari,Kikuta, Naoya,Kimura, Yoshiharu,Shoda, Shin-Ichiro
supporting information, p. 846 - 848 (2015/06/22)
4,6-Dimethoxy-1,3,5-triazin-2-yl glycosides, glycosyl donors prepared in one step from free saccharides without protection of the hydroxy groups, were stereoselectively and equivalently converted to the corresponding 1,2-cis-glycosides by using a catalytic amount of metal catalyst. This reaction was successfully applied not only to monosaccharides, but also to di- and oligosaccharides.
