624-45-3Relevant articles and documents
Design of a highly ordered mesoporous H3PW12O 40/ZrO2-Si(Ph)Si hybrid catalyst for methyl levulinate synthesis
Su, Fang,Ma, Ling,Song, Daiyu,Zhang, Xianghuan,Guo, Yihang
, p. 885 - 890 (2013)
A highly ordered mesoporous ZrO2-based material functionalized by benzene-bridged organosilica groups and the Keggin type heteropolyacid, prepared in a single co-condensation-hydrothermal treatment step, exhibited much higher catalytic activity towards methyl levulinate synthesis compared to alkyl-free H3PW12O40/ZrO2.
Conversion of carbohydrate biomass to methyl levulinate with Al 2(SO4)3 as a simple, cheap and efficient catalyst
Zhou, Lipeng,Zou, Haojie,Nan, Jiaxu,Wu, Lin,Yang, Xiaomei,Su, Yunlai,Lu, Tianliang,Xu, Jie
, p. 13 - 16 (2014)
Al2(SO4)3 was developed as a simple and efficient catalyst for the synthesis of methyl levulinate (MLE) from carbohydrate biomass including fructose, glucose, mannose, sucrose, cellobiose, starch, and cellulose. The maximum MLE yield of 64% from glucose could be obtained at 160 C for 150 min. Important roles of Al3 + and Br?nsted acid sites generated by the hydrolysis/methanolysis of Al 3 + were elucidated. The reaction process was revealed using in situ real-time attenuated total reflection infrared spectroscopy. Al 2(SO4)3 can be regenerated easily and reused at least four times without the loss of activity.
Heteropoly acid and ZrO2 bifunctionalized organosilica hollow nanospheres for esterification and transesterification
Su, Fang,An, Sai,Song, Daiyu,Zhang, Xianghuan,Lu, Bo,Guo, Yihang
, p. 14127 - 14138 (2014)
Single-micelle-templated preparation of heteropoly acid and ZrO2 bifunctionalized organosilica hollow nanospheres (H3PW 12O40/ZrO2-Et-HNS) is developed by co-hydrolysis and -condensation of bissilylated organic precursor, 1,2-bis(trimethoxysilyl)ethane (BTMSE), with a zirconium source (Zr(OC 4H9)4) in the presence of H3PW 12O40, triblock copolymer surfactant F127 and 1,3,5-trimethylbenzene (TMB) followed by boiling ethanol washing. Through tuning the molar ratios of Si/Zr in the initial gel mixture, the morphology transformation from the 3D interconnected mesostructure to the hollow spherical nanostructure is realized. The inner diameter of the H3PW 12O40/ZrO2-Et-HNS materials is in the range of 6-12 nm, and their shell thickness is ca. 2 nm. As novel organic-inorganic hybrid catalysts, the catalytic activity of H3PW12O 40/ZrO2-Et-HNS is evaluated by the model reactions of esterification of levulinic acid (LA) with methanol to methyl levulinate and transesterification of yellow horn oil with methanol to biodiesel at refluxing temperature (65 °C) and atmospheric pressure. The obtained excellent heterogeneous acid catalytic activity of H3PW12O 40/ZrO2-Et-HNS is explained in terms of their strong Broensted and Lewis acidity, unique hollow nanospherical morphology and hydrophobic surface. Finally, the recyclability of the hybrid catalysts is tested through three consecutive catalytic runs. This journal is the Partner Organisations 2014.
1,2-Dioxetanes Derived from 4,5-Dimethyl-2,3-dihydrofuran and 4,5-Dimethyl-2,3-dihydrothiophene: Synthesis via Photooxygenation, Activation Parameters, and Excitation Properties
Adam, Waldemar,Griesbeck, Axel G.,Gollnick, Klaus,Knutzen-Mies, Karen
, p. 1492 - 1495 (1988)
Photooxygenation of 4,5-dimethyl-2,3-dihydrofuran (1a) and 4,5-dimethyl-2,3-dihydrothiophene (1b) in a variety of solvents gave the respective 1,2-dioxetanes 2a,b ( cycloaddition) as major products (82-90percent) and the allylic hydroperoxides 3a,b and 4a,b (ene reaction) as minor products (10-18percent).The 2,3-dihydrofuran-derived dioxetane 2a shows higher thermal stability compared to other known alkoxy-substituted dioxetanes; but more remarkable is the 2,3-dihydrothiophene derivative 2b , the most stable sulfur-substituted dioxetane to date, isolable by molecular distillation.Concerning their excitation properties, both dioxetanes afford preferentially triplet excited state products during thermal decomposition, e.g. ΦT = 3.2 +/- 0.5percent for 2a and ΦT ca. 0.002percent for 2b, the latter being the first triplet exitation yield (ΦT) for a sulfur-substituted dioxetane.Mechanistic rationales for the 1000-fold lower efficiency of generating excited states for the 2,3 -dihydrothiophene dioxetane 2b are presented.
Conversion of carbohydrates to methyl levulinate catalyzed by sulfated montmorillonite
Xu, Xingliang,Zhang, Xianlong,Zou, Weijian,Yue, Huijuan,Tian, Ge,Feng, Shouhua
, p. 67 - 70 (2015)
We reported a highly efficient conversion of carbohydrates such as glucose to methyl levulinate (ML) in methanol with a series of sulfated montmorillonite (MMT) as simple and inexpensive catalysts. Among these catalysts, the MMT treated by H2SO4 after calcination (especially the MMT treated by 20% H2SO4) showed a high catalytic activity. Under the optimal conditions, the conversion of glucose and fructose was up to 100%, and the ML yields obtained from glucose and fructose were 48% and 65%, respectively. The reaction conditions were optimized. Further, the structure and properties of sulfated MMT were characterized.
Acid-catalysed direct transformation of cellulose into methyl glucosides in methanol at moderate temperatures
Deng, Weiping,Liu, Mi,Zhang, Qinghong,Tan, Xuesong,Wang, Ye
, p. 2668 - 2670 (2010)
Cellulose can be transformed into methyl glucosides in methanol with yields of 50-60% in the presence of several acid catalysts under mild conditions (≤473 K); H3PW12O40 provides the highest turnover number (～73 in 0.5 h)
One-pot synthesis of dimethyl succinate from D-fructose using Amberlyst-70 catalyst
He, Liangtu,Huang, Yuzhang,Len, Christophe,Liu, Lei,Miao, Xinge,Wang, Yantao,Yang, Weiran
, (2021/05/19)
Dimethyl succinate (DMS), an important building block of bio-based platform chemicals, was produced from D-fructose under one-pot and metal-free conditions for the first time. In the presence of 1.5 mmol D-fructose, 75 mg Amberlyst-70 and 10 bar O2/
Esterification of levulinic acid over Sn(II) exchanged Keggin heteropolyacid salts: An efficient route to obtain bioaditives
Da Silva, Márcio José,Chaves, Diego Morais,Teixeira, Milena Galdino,Oliveira Bruziquesi, Carlos Giovani
, (2021/03/04)
In this paper, we describe a process to add value to the biomass derivatives (i.e., levulinic acid), converting it to bioadditives over solid Sn(II) exchanged Keggin heteropolyacid salts. These solid catalysts are an attractive alternative to the traditional soluble and corrosive Br?nsted acid catalysts. Among Sn(II) heteropoly salts, the Sn1.5PW12O40 was the most active and selective catalyst, achieving high conversions (ca. 90 %) and selectivity (90–97 %) for alkyl esters and angelica lactone, the main reaction products. The impacts of the main reaction parameters (i.e., catalyst load, temperature, and the molar ratio of alcohol to acid) were investigated. The use of renewable raw material, and an efficient and recyclable catalyst are the main positive features of this process. The Sn1.5PW12O40 catalyst was easily recovered and reused without loss activity.
Efficient alcoholysis of furfuryl alcohol to n-butyl levulinate catalyzed by 5-sulfosalicylic acid
Zhao, Wenguang,Ding, Hui,Tian, Yi,Xu, Qiong,Liu, Xianxiang
, p. 1339 - 1345 (2021/02/26)
It is urgent to study the utilization of biomass energy to solve the environmental problems caused by the excessive use of fossil fuels. In this study, a rapid and efficient route for the conversion of furfuryl alcohol (FA) into n-butyl levulinate (BL) has been catalyzed by 5-sulfosalicylic acid. The nearly complete conversion of FA and a considerable 99.7% selectivity of BL are obtained under the optimal conditions. Based on the experimental results, a possible mechanism for the alcoholysis of FA is proposed. The present study provided a promising way for alkyl levulinates synthesis over economical and environmentally benign catalysts.
Eco-Friendly Natural Clay: Montmorillonite Modified with Nickel or Ruthenium as an Effective Catalyst in Gamma-Valerolactone Synthesis
?erveny, Libor,Trejbal, Ji?í,Vaňková, Michaela,Vrbková, Eva,Vysko?ilová, Eli?ka
, (2021/07/25)
Ni/Ru metals supported on cheap and available support montmorillonite K10 were used for the selective hydrogenation of levulinic acid to γ-valerolactone. Different loadings of the metals were applied by the impregnation method, and detailed characterization was performed (UV–VIS, XRD, TPR, TPD, particle size distribution, SEM, XRF). Metals’ homogeneous distribution on the surface was confirmed. The selectivity to the desired product was almost independent on the used material. A detailed study of the influence of solvents on the studied reaction was also performed—protic alcohol-based solvents caused the formation of levulinic and valeric acid esters in the reaction mixture. The selectivity was influenced mainly by the alcohol structure (the highest selectivity obtained using isopropyl alcohol and sec-butanol). Mainly the solvent’s donor number (except ethanol) influenced the reaction rate. The prepared catalysts are promising, available, and cheap materials for the studied reaction. Solvent may significantly influence the yield of γ-valerolactone. Graphic Abstract: [Figure not available: see fulltext.].
