- Synthesis of glycidol from glycerol and dimethyl carbonate using ionic liquid as a catalyst
-
Transesterification of dimethyl carbonate with glycerol has been investigated using various ionic liquids as catalysts. Synthesis of glycidol with high selectivity (78%) has been achieved using tetramethylammonium hydroxide ([TMA][OH]) as a catalyst at 80°C. Effect of various reaction conditions on the activity and selectivity was investigated and catalyst concentration had a significant influence on conversion as well as selectivity to glycidol. Activity as well as selectivity of the catalyst decreased significantly with increase in moisture content. Recycle experiment indicated slight drop in glycerol conversion and selectivity to glycidol because of dilution of reaction mixture and also the presence of products from the initial experiment.
- Gade, Swapna M.,Munshi, Mudassir K.,Chherawalla, Batul M.,Rane, Vilas H.,Kelkar, Ashutosh A.
-
-
Read Online
- Fluorinated Mg–Al Hydrotalcites Derived Basic Catalysts for Transesterification of Glycerol with Dimethyl Carbonate
-
Abstract: A series of fluorinated Mg–Al hydrotalcite-like (HTl) compounds were prepared by introduction of different amount of (AlF6)3? into HTl sheets via co-precipitation method. The fluorine-modified Mg–Al mixed oxides (CHT-F) with mesoporous structure were then acquired by thermal decomposition of as-prepared HTl precursors. The influence of fluorine modifier on the physicochemical properties of CHT-F samples was studied in detail and the results demonstrated that their structure and basicity were strongly related to the fluorine content. Simultaneously, the CHT-F samples were test for the glycerol carbonate (GC) production via transesterification between glycerol and dimethyl carbonate without organic solvent. For these catalysts, the role of basic sites was examined based on reactant conversion and product selectivities in overall reaction as well as in side reaction identified in this work. The catalytic results showed that the activity of CHT-F catalysts depended on the total number of surface basic sites. However, further study demonstrated that the undesired product was catalyzed by strong basic sites, resulting in decrease of GC selectivity. Thus, the introduction of appropriate amount of (AlF6)3? into the HTl structure can promote the production of GC, and the best catalytic performance was obtained over the catalyst with F:Al = 1.0. Besides, various parameters including reaction time, reaction temperature and catalyst amount were investigated to optimize the reaction conditions. Furthermore, these CHT-F catalysts possessed high stability on the basis of reusability test and catalyst characterization. Graphical Abstract: [Figure not available: see fulltext.].
- Zhang, Xuelan,Wang, Dengfeng,Ma, Jie,Wei, Wei
-
-
Read Online
- Reaction of glycidyl methacrylate at the hydroxyl and carboxylic groups of poly(vinyl alcohol) and poly(acrylic acid): Is this reaction mechanism still unclear?
-
(Chemical Equation Presented) Transesterification and epoxide ring-opening reactions are two mechanism routes that explain chemical modifications of macromolecules by glycidyl methacrylate (GMA). Although the coupling reaction of the GMA with macromolecul
- Reis, Adriano V.,Fajardo, Andre R.,Schuquel, Ivania T. A.,Guilherme, Marcos R.,Vidotti, Gentil Jose,Rubira, Adley F.,Muniz, Edvani C.
-
-
Read Online
- Facile one-pot synthesis of glycidol from glycerol and dimethyl carbonate catalyzed by tetraethylammonium amino acid ionic liquids
-
Four tetraethylammonium amino acid ionic liquids (TAAILs) were prepared and used as catalysts for facile one-pot synthesis of glycidol from glycerol and dimethyl carbonate. The results indicate that tetraethylammonium pipecolinate ([N2222][Pipe]) exhibits the best catalytic activity compared with other three TAAILs, and catalyzes the reaction to reach a glycerol conversion of 96% and a glycidol yield of 79% under optimum conditions. Moreover, DFT calculated results further manifest that such excellent performance originates from the carboxyl group in [N2222][Pipe], which enables [N2222][Pipe] to activate the substrates effectively.
- Zhou, Yan,Ouyang, Fan,Song, Zhi-Bin,Yang, Zhen,Tao, Duan-Jian
-
-
Read Online
- Aerobic oxidation of methyl p-Tolyl sulfide catalyzed by a remarkably labile heteroscorpionate Ru(II)-aqua complex, fac-[RuII(H2O)(dpp)(tppm)]2+
-
fac-[RuII(Cl)(dpp)(L3)]+ (L3 = tris(pyrid-2-yl)methoxymethane (tpmm) = [1A]+ and tris(pyrid-2-yl)pentoxymethane (tppm) = [1B]+ and dpp = di(pyrazol-1-yl)propane) rapidly undergo ligand substitution with water to form fac-[RuII(H2O)(dpp)(L3)]2+ (L3 = tpmm = [2A]2+ and tppm = [2B]2+). In the structure of [2A]2+, the distorted octahedral arrangement of ligands around Ru is evident by a long Ru(1)-O(40) of 2.172(3) A and a large (40)-Ru (1)-N(51) of 96.95(14)° The remarkably short distance between O (40) of H 2O and H (45a) of dpp confirms the heteroscorpionate ligand effect fo dpp H 2O [2B] 2+ aerobically catalyzes methl p-toyl sulfide to methyl p-toyl sulfoxide in 1,2 dichlorobenzene at 25.0 ± 0.1 ° C under 11.4 psi of O2.Experimental facts in support of this aerobic sulfide oxidation are the absence of H 2O2 and the oxidative readctive of the putative Ru(IV)-oxo intermediate toward methl p-tolyl Sulfide, 2- propanol, and allyl alcohal This study provides the first documented example of aerobic-sulfide oxidation catalyzed by the remarkably labile heteroscorpionate Ru (III)- aqua complex without the formation of a highly reactive peroxide as an intemediate. Copyright
- Huynh, My Hang V.,Witham, Laura M.,Lasker, Joanne M.,Wetzler, Modi,Mort, Brendan,Jameson, Donald L.,White, Peter S.,Takeuchi, Kenneth J.
-
-
Read Online
- Efficient synthesis of glycerol carbonate/glycidol using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) based ionic liquids as catalyst
-
Transesterification of dimethyl carbonate with glycerol to glycerol carbonate has been catalyzed efficiently using basic ionic liquids as catalysts. Activity of all the ILs tested is very high and the best result (96% conversion with 82% selectivity to glycerol carbonate and 18% selectivity to glycidol) was obtained using IL1 as catalyst. The effect of catalyst loading has significant influence on the selectivity pattern. The higher activity of the ionic liquid is explained with a plausible mechanism based on the co-operative effect of both cation and anion.
- Munshi, Mudassir K.,Biradar, Pradeep S.,Gade, Swapna M.,Rane, Vilas H.,Kelkar, Ashutosh A.
-
-
Read Online
- A novel titanosilicate with MWW structure III. Highly efficient and selective production of glycidol through epoxidation of allyl alcohol with H2O2
-
The catalytic properties of Ti-MWW in the epoxidation of allyl alcohol (AAL) with hydrogen peroxide to glycidol (GLY) have been studied in detail by a comparison with those of TS-1 and pure silica Ti-Beta, and mechanical considerations have been given to the relation between the catalytic performance and the structural, acidic, and hydrophilic/hydrophobic nature of titanosilicates. Ti-MWW catalyzed the AAL epoxidation more actively and selectively than TS-1 and Ti-Beta in the presence of H2O or MeCN, and exhibited a conversion of 95% for AAL and a selectivity of 99% for GLY when the AAL epoxidation was carried out at 333 K for 30 min and at 12 wt% of catalyst to substrate. Ti-MWW proved to be a reusable and sustainable catalyst as it stood up to Ti leaching and maintained the catalytic activity and the product selectivity in the reaction-regeneration cycles. The acidic character due to the boron framework was very weak, and thus contributed negligibly to the solvolysis of GLY. The AAL epoxidation proceeded mainly within the intralayer sinusoid 10-MR channels which supplied more steric fitness to the substrate molecules than the tunnel-like channels of TS-1 ad Ti-Beta. Ti-MWW was more hydrophilic than TS-1, but much more hydrophobic than Ti-Beta. The hydrophilicity of Ti-MWW was presumed to derive mainly from the defect sites due to the incomplete dehydroxylation between the layers and partially as a result of deboronation. The sinusoidal 10-MR channels serving as the reaction space for the AAL epoxidation were considered to be hydrophobic, thus rendering the Ti-MWW catalyst applicable to the substrates and solvents, both of a polar nature.
- Wu, Peng,Tatsumi, Takashi
-
-
Read Online
- 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU): A highly efficient catalyst in glycerol carbonate synthesis
-
Transesterification of dimethyl carbonate (DMC) with glycerol (GLY) was investigated using various amines as catalysts. Amidines like 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) were found to be the best catalysts for this reaction. Best results: 98% conversion of GLY with 96% selectivity to GC (TON: 9408), were obtained with DBU as a catalyst. Effect of various reaction conditions on activity and selectivity were investigated using DBU as catalyst. The mechanism of the reaction was investigated with the help of 1H, 13C and 15N NMR analysis and DFT calculations.
- Munshi, Mudassir K.,Gade, Swapna M.,Mane, Manoj V.,Mishra, Deepti,Pal, Sourav,Vanka, Kumar,Rane, Vilas H.,Kelkar, Ashutosh A.
-
-
Read Online
- Synthesis of glycerol carbonate by transesterification of glycerol and dimethyl carbonate over KF/γ-Al2O3 catalyst
-
Series of KF/γ-Al2O3 solid base catalysts were prepared by a wet impregnation method and applied to the synthesis of glycerol carbonate (GC) from glycerol and dimethyl carbonate. The influences of KF loading and calcination temperature of catalyst on the synthesis were investigated. The results showed that KF/γ-A12O3 catalysts could promote glycerol conversion to GC efficiently. The structure and properties of the catalysts were studied by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2-adsorption, CO2-temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS) and Hammett indicator method. It was found that several types of basic centers such as KF, KAlO2, KOH and possibly coordinately unsaturated F-ion existed on the catalysts. The strong basic centers could not only accelerate the conversion of glycerol, but also enhance the formation of glycidol from the decomposition of GC. The recycling of KF/γ-A1 2O3 revealed that deactivation of catalyst was strengthened with the reuse times, which was mainly caused by the partial leaching of active potassium species. High calcination temperature favored the transformation of KF to KAlO2 and alleviated the deactivation of the catalyst. Based on the product distribution and obtained results, a possible reaction mechanism on reaction of glycerol with dimethyl carbonate was proposed.
- Liu, Zhenmin,Wang, Junwei,Kang, Maoqing,Yin, Ning,Wang, Xinkui,Tan, Yisheng,Zhu, Yulei
-
-
Read Online
- Role of cation-anion cooperation in the selective synthesis of glycidol from glycerol using DABCO-DMC ionic liquid as catalyst
-
Transesterification of dimethyl carbonate with glycerol has been investigated using 1,4-diazabicyclo [2.2.2] octane (DABCO) based ionic liquid as a catalyst. DABCO reacted with dimethyl carbonate to form ionic liquid as the reaction progressed. Though the basicity of DABCO based ionic liquid was lower than that of DABCO, the catalytic activity and selectivity to glycidol was higher with DABCO based ionic liquid as a catalyst, indicating that basicity may not be the only criterion in deciding activity and selectivity of the reaction. The cooperative effect of the cation and anion of the ionic liquid is responsible for the observed results. The best results (97% glycerol conversion with 83% selectivity to glycidol and 17% selectivity to glycerol carbonate) were obtained using DABCO based ionic liquid as a catalyst. A plausible mechanism involving the role of both the cation and anion of the ionic liquid has been proposed. the Partner Organisations 2014.
- Munshi, Mudassir K.,Gade, Swapna M.,Rane, Vilas H.,Kelkar, Ashutosh A.
-
-
Read Online
- Consecutive carbonylation and decarboxylation of glycerol with urea for the synthesis of glycidol via glycerol carbonate
-
Zn(OAc)2-catalyzed carbonylation and decarboxylation of glycerol and urea for the synthesis of glycidol were conducted at 150?°C, 2.7?kPa for 2?h and 170?°C, 2.0?kPa for 1.5?h, respectively. When the reaction conducted in a one-pot consecutive way, the yield of glycidol was 20%. However, when the formed zinc glycerolate (Zn(C3H6O3)) was filtered out after the carbonylation, the yield increased to 50% with respect to the amount of glycerol, whereas the yields of glycidol were very low when other zinc salts such as ZnCl2, ZnSO4 and Zn(NO3)2, were used as catalysts. The high catalytic activity of Zn(OAc)2 for this carbonylation and decarboxylation of glycerol and urea could be ascribed to the formation of Zn(NH3)x(OAc)2, which was determined from IR and TOF-SIMS studies.
- Endah, Yohana Kurnia,Kim, Min Soo,Choi, Jisik,Jae, Jungho,Lee, Sang Deuk,Lee, Hyunjoo
-
-
Read Online
- Structural characteristics and harmonic vibrational analysis of the stable conformer of 2,3-epoxypropanol by quantum chemical methods
-
The FT-IR and FT-Raman spectra of H bond inner conformer of 2,3-epoxypropanol have been recorded in the regions 3700-400 and 3700-100 cm-1, respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The normal coordinate analysis was carried out to confirm the precision of the assignments. The structure of the conformers H bond inner and H bond outer1 were optimised and the structural characteristics were determined by density functional theory (DFT) using B3LYP and MP2 methods with 6-31G and 6-311++G basis sets. The vibrational frequencies were calculated in all these methods and were compared with the experimental frequencies which yield good agreement between observed and calculated frequencies. The electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach.
- Arjunan,Rani,Santhanam,Mohan
-
-
Read Online
- Synthesis of glycidol by decarboxylation of glycerol carbonate over Zn-La catalysts with different molar ratio
-
Zinc-Lanthanum (Zn-La) mixed oxides are prepared with different molar ratios and used as catalysts for the synthesis of glycidol by decarboxylation of glycerol carbonate. The prepared catalysts were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption and NH3/CO2 thermal programmed desorption (TPD) methods. The XRD patterns show that Zn-La mixed oxide exhibit both ZnO and La2O3 phases, mixed metal oxides are better in terms of specific surface area and porosity compared to pure metal oxide. From the TPD results, it observed that the ratio of acid/base site on the prepared catalyst is closer to 1 with increase of La molar. The catalytic performance of Zn-La catalysts was strongly dependent on their molar ratio; the highest glycidol yield was observed 76.22% with Zn/La = 1/9 catalyst. Above these results, acidic and basic properties of prepared catalyst were considered to play an important role in the synthesis of glycidol by decarboxylation of glycerol carbonate.
- Ha, Ji Hae,Kim, Ji Sun,Kim, Myung Hwan,Lee, Kwan Young,Lee, Man Sig
-
-
Read Online
- Catalytic epoxidation by perrhenate through the formation of organic-phase supramolecular ion pairs
-
Organic-phase supramolecular ion pair (SIP) host-guest assemblies of perrhenate anions (ReO4-) with ammonium amide receptor cations are reported. These compounds act as catalysts for the epoxidation of alkenes by aqueous hydrogen peroxide under biphasic conditions and can be recycled several times with no loss in activity.
- Cokoja, Mirza,Markovits, Iulius I. E.,Anthofer, Michael H.,Poplata, Saner,P?thig, Alexander,Morris, Danny S.,Tasker, Peter A.,Herrmann, Wolfgang A.,Kühn, Fritz E.,Love, Jason B.
-
-
Read Online
- Synthesis of glycerol carbonate over porous La-Zr based catalysts: The role of strong and super basic sites
-
As important glycerol derivatives, glycerol carbonate (GC) and glycidol (GD) have attracted increasing attention in recent years. In the present work, a series of new solid base catalysts were developed to catalyze the conversion of glycerol to afford GC and GD. These catalysts were prepared by loading KF on the porous La-Zr solid base catalyst and characterized using a series of methods. A large number of various basic sites were generated upon loading KF onto the La-Zr-600 support. The weak basic sites were assigned to the surface hydroxyl groups produced during the formation of LaOF, while the strong and super basic sites were related to the Lewis base produced due to the interaction between KF and the La-Zr-600 support. A glycerol conversion of 91.77% and a GC selectivity of 99% were obtained over 0.3KF/La-Zr, which displayed the best catalytic performance under the optimal reaction conditions. The excellent activity of these catalysts was attributed to the presence of the strong and super basic sites, which favor the transesterification of glycerol with dimethyl carbonate. The production of GD from GC decarbonylation was unfeasible at low temperature using the newly developed catalysts. A plausible reaction mechanism has been proposed based on the experimental results and characterization.
- Song, Xianghai,Pan, Donghui,Wu, Yuanfeng,Cheng, Pin,Wei, Ruiping,Gao, Lijing,Zhang, Jin,Xiao, Guomin
-
-
Read Online
- Synthesis of glycerol 1,2-carbonate by transesterification of glycerol with dimethyl carbonate using triethylamine as a facile separable homogeneous catalyst
-
The synthesis of glycerol 1,2-carbonate (GC) by transesterification of glycerol with dimethyl carbonate (DMC) using triethylamine (TEA) as a facile separable homogeneous catalyst has been studied at different temperatures, DMC/glycerol molar ratios and TE
- Ochoa-Gomez, Jose R.,Gomez-Jimenez-Aberasturi, Olga,Ramirez-Lopez, Camilo,Maestro-Madurga, Belen
-
-
Read Online
- Solvent free transesterification of glycerol into glycerol carbonate over nanostructured CaAl hydrotalcite catalyst
-
Drastic increase in green house gases due to fossil fuels usage urges the mankind to look for alternative fuel resources. Biodiesel is one of the alternative fuels which attracted the attention of many researchers. In recent years, bio-diesel drags much attention as an alternative clean fuel. Glycerol is an unavoidable byproduct in the transesterification process of vegetable oils into bio diesel and therefore market is flooded with glycerol. So it is high time to find ways of utilizing the abundant glycerol into value added products. Herein we report the catalytic transesterification of glycerol using dimethyl carbonate over MgAl-hydrotalcite (MgAl-HT), CaAl-hydrotalcite (CaAl-HT) and nano structured CaAl-HT catalysts. All the catalysts were characterized by XRD, FT-IR, TPDCO2, BET, SEM and HR-TEM techniques. Among them Ca4Al-HT was found to be best in terms of conversion of glycerol (82.4%) and selectivity (95.9%) towards glycerol carbonate. The effect of CTAB template concentration in the nano synthesis of Ca4Al-HT on conversion and selectivity was studied and Ca4Al-HT synthesized with 0.4 moles of CTAB showed the best conversion of glycerol (98.7%) and the highest selectivity towards glycerol carbonate (97.9%). The recyclability test performed with the best catalyst showed that the catalyst was recyclable even after 5 cycles. Valorization of glycerol yields glycerol carbonate (GC) which is a very good polar solvent with high boiling point, building block in several organic syntheses and used in the production of surfactants, poly urethanes etc.
- Devarajan, Arulselvan,Thiripuranthagan, Sivakumar,Radhakrishnan, Ramakrishnan,Kumaravel, Sakthivel
-
-
Read Online
- Deuterium magnetic resonance as a probe for organic reaction mechanisms: Epoxidation of 1(3)-tosylglycerol is a pure SN2 cyclisation
-
A stereoselective deuteriation of glycerol acetonide is used to prove by means of deuterium NMR spectroscopy that the cyclisation of glycerol tosylate into glycidol is a pure SN2 mechanism.
- Rabiller,Mesbahi,Levayer
-
-
Read Online
- Regularities of glycidol synthesis by the liquid-phase epoxidation of allyl alcohol with hydrogen peroxide
-
The main features of the liquid-phase epoxidation of allyl alcohol by hydrogen peroxide in an organic solvent in the presence of the titanium-containing zeolite in the batch reactor were studied. The influence of the amount of the solvent, ratio of reactants, and temperature on the rate of glycidol synthesis was revealed.
- Sulimov,Danov,Ovcharova,Ovcharov,Flid
-
-
Read Online
- High-efficiency and low-cost Li/ZnO catalysts for synthesis of glycerol carbonate from glycerol transesterification: The role of Li and ZnO interaction
-
A series of efficient and low-cost Li/ZnO catalysts were prepared by a simple impregnation method and investigated for the synthesis of glycerol carbonate (GC) from the transesterification of glycerol with dimethyl carbonate (DMC). The Li/ZnO catalysts were characterized using XRD, SEM, FT-IR, TG-DSC, TPD and XPS. It was found that the basicity of the catalysts highly depended on the Li loading and calcination temperature. The weak and moderate basic sites on the catalyst surfaces originated from the ZnO and Li+interaction. The strong basic sites were attributed to the substitution of Zn2+by Li+in the ZnO lattice, which led to straining of Zn-O bonds and the formation of [Li+O?] species. It was the strong basic sites rather than the weak and moderate basic sites that catalyzed the transesterification of glycerol with DMC. The highest catalytic activity was observed over the ZnO loaded with 1 wt.% LiNO3and calcined at 500 °C. Glycerol conversion of 97.40% and GC yield of 95.84% were obtained over this catalyst at 95 °C in 4 h.
- Song, Xianghai,Wu, Yuanfeng,Cai, Fufeng,Pan, Donghui,Xiao, Guomin
-
-
Read Online
- Investigation of physicochemical properties for novel perrhenate ionic liquid and its catalytic application towards epoxidation of olefins
-
Abstract: A novel ionic liquid (IL) based on catalytic functional metal rhenium, [Smim][ReO4] (1-heptyl-3-methyl-imidazolium perrhenate) was synthesized and characterized. Density and surface tension values of the IL were determined at different temperatures, and the volume and surface properties were calculated and discussed, respectively. Furthermore, the synthesized ionic liquid [Smim][ReO4] was used as a green solvent and catalyst for homogeneous catalyzed epoxidation of olefin with urea hydrogen peroxide (UHP) oxidant. The effect of factors of catalyst, oxidant, reaction time, and reaction temperature was discussed. The conversion of cyclohexene and cyclooctene is over 99% at optimum conditions. The IL [Smim][ReO4] as catalyst and solvent are characterized by high efficiency, long service life and recoverability, which is a better green homogeneous catalyst for epoxidation of olefins. Graphic Abstract: A novel IL based on catalytic functional metal rhenium, [Smim][ReO4] was synthesized and characterized. The volume and surface properties were calculated and discussed by the density and surface tension values at different temperatures, respectively. Furthermore, the as-synthesized [Smim][ReO4] was used as a green solvent and catalyst for homogeneous catalyzed epoxidation of olefin with urea hydrogen peroxide (UHP) oxidant. The results showed that the yield and selectivity of the reaction were up to 99%, and the catalytic efficiency of [Smim][ReO4] did not decrease significantly after five times recycling. Easy separation, recycle, nontoxicity and homogeneous catalysis are the main advantages of perrhenate ionic liquids over other heterogeneous catalysts containing organic solvents.[Figure not available: see fulltext.].
- Song, Zongren,Liu, Xueke,Zhang, Hao,Fang, Dawei,Ma, Xiaoxue
-
-
- Role of Organic Fluoride Salts in Stabilizing Niobium Oxo-Clusters Catalyzing Epoxidation
-
We present here that easily available organic salts can stabilize/modify niobium (Nb) oxo-clusters. The as-synthesized Nb oxo-clusters have been characterized by various methods. These Nb oxo-clusters were catalytically active for the epoxidation of allylic alcohols and olefins with H2O2 as an oxidant. Notably, Nb-OC@TBAF-0.5 appeared as highly dispersed nanosized particles and showed the highest catalytic activity, which can be attributed to the following reasons on the basis of characterization. First, the strong coordination of fluorine ions with Nb sites and the steric protection with bulky organic cations led to high stabilization and dispersion of the oxo-clusters in the course of the reaction. Second, a hydrogen-bond interaction between the coordinated fluorine atom and the -OH group of allylic alcohol favored the epoxidation reaction. Third, the electron density of Nb sites decreased due to the strong electron-withdrawing ability of F- adjacent to Nb sites, thus promoting the electrophilic oxygen transfer to the CC bond.
- Dai, Sheng,Ding, Bingjie,Gong, Xueqing,Hou, Zhenshan,Li, Difan,Tang, Xuan,Xu, Beibei,Yao, Yefeng,Zhang, Tong,Zheng, Anna,Zhou, Qingqing
-
p. 8190 - 8203
(2021/07/26)
-
- Kinetics and Mechanism of Allyl Alcohol Epoxidation with Hydrogen Peroxide on a Titanium Silicalite Catalyst TS-1. Formulation and Discrimination between Hypothetical Mechanisms
-
Abstract: The kinetics of epoxidation of allyl alcohol with hydrogen peroxide in the presence of a titanium-containing zeolite catalyst TS-1 has been studied. The hypothetical mechanisms of varying degrees of complexity were proposed with further discrimination. The results of the kinetic study allow us to conclude the following: inclusion of rate inhibition of the process by the resulting product (glycidol) is an essential condition for adequate description of the kinetic dependences of epoxidation. It was established that both the Eley–Rideal type mechanism and the Langmuir–Hinshelwood mechanism with activation of allyl alcohol and hydrogen peroxide at different catalyst sites make it possible to describe the kinetic regularities within the experimental error. Further discrimination requires additional studies.
- Bruk, L. G.,Katsman, E. A.,Levitin, V. V.,Pastukhova, Zh. Yu.
-
p. 604 - 620
(2021/09/28)
-
- Preparation of zeolitic bismuth vanadomolybdate using a ball-shaped giant polyoxometalate for olefin epoxidation
-
Zeolitic octahedral metal oxides are interesting materials that have received increasing attention. A bismuth vanadomolybdate-based zeolitic octahedral metal oxide was synthesized using a ball-shaped polyoxovanadomolybdate with different Bi sources. The material was used as a heterogeneous catalyst for olefin epoxidation. Different olefins were converted to their corresponding epoxides by the catalyst under mild conditions. This robust catalyst was reused several times without loss of activity.
- Hara, Michikazu,Li, Denan,Li, Yanshuo,Ueda, Wataru,Zhang, Zhenxin,Zhu, Qianqian
-
p. 21624 - 21630
(2021/12/09)
-
- Preparation method for 1,3-propylene glycol from glycerol
-
The invention relates to a preparation method for 1,3-propylene glycol from glycerol, wherein the preparation method comprises the steps of chlorohydrination reaction, cyclization reaction, hydrogenation reaction and the like. The glycerin conversion rate of the preparation method reaches 99% or above, the yield of 1,3-propylene glycol reaches 65% or above, and the preparation method has the advantages of being simple in process, mild in reaction condition, small in investment, high in technical safety and easy to operate and control.
- -
-
Paragraph 0066-0076
(2021/04/10)
-
- Tris-imidazolinium-based porous poly(ionic liquid)s as an efficient catalyst for decarboxylation of cyclic carbonate to epoxide
-
A series of imidazolinium-based porous poly(ionic liquid)s (PILs) with different anions prepared by free-radical copolymerization of an arene-bridged tris-vinylimidazolium salt and divinylbenzene (DVB) were constructed. The as-prepared PILs were characterized by BET, SEM, TEM, TGA and Elemental Analysis (EA), and the results showed that they had plentiful ionic sites, and abundant and stable mesopores. In particular, the density of ionic sites and pore structure of PILs could be controlled by adjusting the content of DVB. Moreover, the PILs were used as efficient heterogeneous catalysts for the decarboxylation of cyclic carbonates to epoxides for the first time. Results showed that the catalytic activity of PILs was positively correlated with the nucleophilicity of the anions in PILs, and PDVB-[PhTVIM]Cl-1 with a chloride anion-enriched skeleton displayed the best catalytic performance. Without any solvent or cocatalyst, PDVB-[PhTVIM]Cl-1 achieved a TOF value of 108.1 h-1and the yield of butylene oxide of 89.6%, which was even better than the homogeneous IL-based catalysts (TOF value: 8.7 h-1) that had been previously reported. Meanwhile, PDVB-[PhTVIM]Cl-1 also exhibited excellent recyclability and substrate compatibility.
- Li, Yang,Wang, Liguo,Cao, Yan,Xu, Shuang,He, Peng,Li, Huiquan,Liu, Hui
-
p. 14193 - 14202
(2021/04/22)
-
- Tuneable transesterification of glycerol with dimethyl carbonate for synthesis of glycerol carbonate and glycidol on MnO2 nanorods and efficacy of different polymorphs
-
Bioglycerol must be valorized to make biodiesel competitive vis-à-vis petro-diesel price. Glycerol carbonate is a sustainable chemical used by many industries. Various routes are reported but there exists a scope to develop better catalytic routes for selective synthesis of glycerol carbonate. Different polymorphs of MnO2 were explored as catalyst for the first time in the synthesis of glycerol carbonate by transesterification of glycerol with dimethyl carbonate under solvent-free conditions. The effect of microwave condition versus conventional heating was compared vis-a-vis conversion of glycerol, selectivity of glycerol carbonate and glycidol. Microwave heating (80 °C) was advantageous over conventional heating (120 °C). Different mesoporous polymorphs of MnO2 were prepared by hydrothermal synthesis and the activity of each polymorph was screened for transesterification reaction of glycerol. All MnO2 polymorphs were completely characterized. δ-MnO2 was the most active, selective, robust and recyclable catalyst. A kinetic model was developed. The overall process is green and sustainable.
- Deshmukh, Gunjan P.,Yadav, Ganapati D.
-
-
- Mixed tetradentate NHC/1,2,3-triazole iron complexes bearing cis labile coordination sites as highly active catalysts in Lewis and Br?nsted acid mediated olefin epoxidation
-
Two bio-inspired non-heme iron complexes bearing mixed tetradentate N-heterocyclic carbene/1,2,3-triazole ligands with cis labile coordination sites are reported. The compounds are studied in olefin epoxidation catalysis using H2O2 as oxidant. Sc(OTf)3, HClO4 and HOAc are applied as additives resulting in significant improvement of catalytic performance. Under optimized conditions the most active catalyst exhibits activities of 76,000 turnovers per hour, which is the highest reported value for an iron(II) catalyst. The complexes reveal comparably high stability and enable the challenging epoxidation of functionalized olefins. These results prove 1,2,3-triazoles to be promising and tunable ligands for iron catalyzed oxidation reactions.
- Dyckhoff, Florian,Jakob, Christian H. G.,Kühn, Fritz E.,Nguyen, Linda,Reich, Robert M.,Schlagintweit, Jonas F.
-
p. 144 - 152
(2020/02/04)
-
- Three- and two-site heteropolyoxotungstate anions as catalysts for the epoxidation of allylic alcohols by H2O2 under biphasic conditions: Reactivity and kinetic studies of the [Ni3(OH2)3(B-PW9O34){WO5(H2O)}]7?, [Co3(OH2)6(A-PW9O34)2]12?, and [M4(OH2)2(B-PW9O34)2]10? anions, where M?=?Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)
-
The trimetallic phosphopolyoxotungstate anions [Ni3(OH2)3(B-PW9O34){WO5(H2O)}]7? and [Co3(OH2)6(A-PW9O34)2]12? have been studied as epoxidation catalysts for oxygen transfer from 30% H2O2 to a range of allylic alcohols under biphasic conditions (1,2-dichloroethane/H2O) at 15 °C. The reaction mechanism involves coordination of an allylic alcohol at an M(II) site in each case, prior to transfer of a peroxy oxygen from an adjacent W(O2) site. The latter is formed from a terminal W = O unit by reaction with H2O2. Evidence of W(O2) formation was obtained through IR studies. The W(O2) group forms the epoxide by transfer of an oxygen atom to the C[dbnd]C bond of the coordinated allylic alcohol. Kinetic studies using 3-methyl-2-buten-1-ol as the allylic alcohol substrate have been modelled with all three metal sites catalytically active. The reaction involves an autocatalysis mechanism involving an induction period, which can be rationalised by proposing not only coordination of the allylic alcohol to M(II), but also the product hydroxy epoxide, both through their –OH groups. The autocatalysis is generated by formation of the W(O2) group adjacent to a coordinated hydroxy epoxide, which competes with coordination of allylic alcohol. The mechanism requires some twenty-one steps involving just the generic steps listed above, with all three metal sites catalytically active. Temperature-dependent kinetic studies and subsequent Eyring analyses have shown that the Co(II)-containing catalyst is the most active of the two. Analogous studies of the epoxidation of 3-methyl-2-buten-1-ol by the two-site [M4(OH2)2(B-PW9O34)2]10? ions as catalysts, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II), at 15 °C gave an order of reactivity of Cu(II) > Ni(II) > Zn(II), Co(II), Mn(II), which mostly mimics the natural order of stability constants (the Irving-Williams series), suggesting that the formation of the allylic alcohol complexes play a dominant role in this series of related complex anions, with greater replacement of water by allylic alcohol leading to greater reactivity.
- Abram, Paulus Hengky,Burns, Robert C.,Li, Lichun
-
-
- Ionic liquid surfactants as multitasking micellar catalysts for epoxidations in water
-
We present a single-component catalyst system for the epoxidation of hydrophobic olefins in aqueous solution. The aggregation of surface-active 1-alkyl-3-methylimidazolium ionic liquids (IL) containing the catalytically active tungstate dianion leads to micelles, which solubilise apolar olefins in aqueous media. The micellisation of tungstate allows for the epoxidation of cyclooctene and other olefins in water, using environmentally benign hydrogen peroxide as oxidant. The structural characterisation of the micelles under catalysis conditions as well as the substrate uptake have been studied by cryo-TEM. 183W-NMR studies revealed that the catalytically active species is a tetraperoxotungstate complex. The addition of organophosphonic acids results in a significant boost of the catalytic activity by formation of a tungstate-phosphonate adduct, investigated using electrospray ionisation mass spectrometry (ESI-MS). The versatile functionalisability of the imidazolium cation enables a covalent linkage of a phosphonate group, which is further increasing the catalytic activity.
- Cokoja, Mirza,Jess, Andreas,Korth, Wolfgang,Schmidt, Fabian,Zehner, Bastian
-
p. 4448 - 4457
(2020/07/14)
-
- One-step synthesis of ethanol from glycerol in a gas phase packed bed reactor over hierarchical alkali-treated zeolite catalyst materials
-
The gas-phase conversion of glycerol into ethanol in a "green" one-step synthesis over a cesium metal-promoted zeolite catalyst has been reported for the first time. To our knowledge, the CsZSM-5 based catalyst presented in this work showed one of the best yields of ethanol in the gas-phase glycerol conversion. The catalyst sample's structure, texture, and acid-base properties were characterized using numerous materials characterization techniques. The catalytic evaluation was carried out in a packed-bed continuous flow reactor. The highest ethanol yield achieved was 99.6 mol% over a 20 wt% CsZSM-5 catalyst with SiO2/Al2O3 = 1500, 10 wt% glycerol feed concentration, 350 °C reaction temperature, and GHSVtotal = 625 h-1. It was demonstrated that the best catalytic performance was related to the ample amount of surface basic sites, synergistic interaction between Cs species and the HZSM-5 zeolite and to its smaller crystallite size obtained from XRD analysis. The achieved results exhibit great potential of utilizing the alkali-treated CsZSM-5 catalyst for the gas-phase conversion of glycerol into bio-based ethanol. The possible reaction route from glycerol to renewable ethanol was proposed based on direct glycerol conversion to ethanol via the thermal monodehydration, radical fragmentation, methylation and transfer hydrogenation reactions. Finally, for the first time, methanol was directly converted into ethanol in the gas-phase continuous flow packed-bed reactor over a 20 wt% CsZSM-5 catalyst.
- Kostyniuk, Andrii,Bajec, David,Likozar, Bla?
-
p. 753 - 765
(2020/02/27)
-
- A mononuclear tantalum catalyst with a peroxocarbonate ligand for olefin epoxidation in compressed CO2
-
A new class of tantalum-based peroxocarbonate ionic liquid ([P4,4,4,4]3[Ta(η2-O2)3(CO4)]) has been generated through the reaction of pressurized CO2 with [P4,4,4,4]3[Ta(O)3(η2-O2)] in the presence of H2O2 during the reaction process. The newly formed species has been verified by NMR, FT-IR, HRMS and density functional theory (DFT) calculations. The CO2-induced monomeric peroxocarbonate anion-based ionic liquid is more advantageous than the monomeric peroxotantalate analogue for the epoxidation of olefins under very mild conditions. Interestingly, the transformation between peroxotantalate and peroxocarbonate species is completely reversible, and CO2 can actually act as a trigger agent for epoxidation reaction. The further mechanism studies by DFT calculation reveal that peroxo η2-O2 (site a) affords higher reactivity towards the CC bond than that of peroxocarbonate-CO4 (site b). These quantitative illustrations of the relationship between structural properties and kinetic consequences enable rational design for an efficient and environmental IL catalyst for the epoxidation of olefins.
- Ma, Wenbao,Qiao, Yunxiang,Theyssen, Nils,Zhou, Qingqing,Li, Difan,Ding, Bingjie,Wang, Dongqi,Hou, Zhenshan
-
p. 1621 - 1630
(2019/04/10)
-
- Diastereoselective Desymmetrization of p-Quinamines through Regioselective Ring Opening of Epoxides and Aziridines
-
A highly diastereoselective desymmetrization of p-quinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. A chairlike six-membered transition state with minimized 1,3-diaxial interactions explains the relative stereoselectivity of the cyclization reaction. This transition-metal free [3 + 3] annulation reaction provides rapid access to fused bicyclic morpholines and piperazines with a tetrasubstituted carbon center in high yields. In addition, it also allows the synthesis of enantioenriched products by using easily accessible chiral nonracemic epoxides and aziridines.
- Jadhav, Sandip B.,Chegondi, Rambabu
-
supporting information
p. 10115 - 10119
(2019/12/24)
-
- Highly selective and efficient olefin epoxidation with pure inorganic-ligand supported iron catalysts
-
Over the past two decades, there have been major developments in the transition iron-catalyzed selective oxidation of alkenes to epoxides; a common structure found in drug, isolated natural products, and fine chemicals. Many of these approaches have enabled highly efficient and selective epoxidation of alkenes via the design of specialized ligands, which facilitates to control the activity and selectivity of the reactions catalyzed by iron atom. Herein, we report the development of the olefin epoxidation with inorganic-ligand supported iron-catalysts using 30% H2O2 as an oxidant, and the mechanism is similar to iron-porphyrin type. With the catalyst 1, (NH4)3[FeMo6O18(OH)6], various aromatic and aliphatic alkenes were successfully transformed into the corresponding epoxides with excellent yields as well as chemo- and stereo-selectivity. This catalytic system possesses the advantages of being able to avoid the use of expensive, toxic, air/moisture sensitive and commercially unavailable organic ligands. The generality of this methodology is simple to operate and exhibits high catalytic activity as well as excellent stability, which gives it the potential to be used on an industrial scale, and maybe opens a way for the catalytic oxidation reaction via inorganic-ligand coordinated iron catalysis.
- Zhou, Zhuohong,Dai, Guoyong,Ru, Shi,Yu, Han,Wei, Yongge
-
supporting information
p. 14201 - 14205
(2019/10/02)
-
- Continuous flow upgrading of glycerol toward oxiranes and active pharmaceutical ingredients thereof
-
A robust continuous flow procedure for the transformation of bio-based glycerol into high value-added oxiranes (epichlorohydrin and glycidol) is presented. The flow procedure features a central hydrochlorination/dechlorination sequence and provides economically and environmentally favorable conditions involving an organocatalyst and aqueous solutions of hydrochloric acid and sodium hydroxide. Pimelic acid (10 mol%) shows an exceptional catalytic activity (>99% conversion of glycerol, a high selectivity toward 1,3-dichloro-2-propanol and 81% cumulated yield toward intermediate chlorohydrins) for the hydrochlorination of glycerol (140 °C) with 36 wt% aqueous HCl. These conditions are validated on a sample of crude bio-based glycerol. The dechlorination step is effective (quantitative conversion based on glycerol) with concentrated aqueous sodium hydroxide (20 °C) and can be directly concatenated to the hydrochlorination step, hence providing a ca. 2:3 separable mixture of glycidol and epichlorohydrin (74% cumulated yield). An in-line membrane separation unit is included downstream, providing usable streams of epichlorohydrin (in MTBE, with an optional concentrator) and glycidol (in water). The scalability of the dechlorination step is then assessed in a commercial pilot-scale continuous flow reactor. Next, bio-based epichlorohydrin is further utilized for the continuous flow preparation of β-amino alcohol active pharmaceutical ingredients including propranolol (hypertension, WHO essential), naftopidil (prostatic hyperplasia) and alprenolol (angina pectoris) within a concatenable two-step procedure using a FDA class 3 solvent (DMSO). This work provides the first example of direct upgrading of bio-based glycerol into high value-added pharmaceuticals under continuous flow conditions.
- Morodo, Romain,Gérardy, Romaric,Petit, Guillaume,Monbaliu, Jean-Christophe M.
-
p. 4422 - 4433
(2019/08/21)
-
- Versatile and scalable synthesis of cyclic organic carbonates under organocatalytic continuous flow conditions
-
The benchmark route for the preparation of cyclic organic carbonates starts from toxic, volatile and unstable epoxides. In this work, cyclic organic carbonates are prepared according to alternative sustainable and intensified continuous flow conditions from the corresponding 1,2-diols. The process utilizes dimethyl carbonate (DMC) as a low toxicity carbonation reagent and relies on the organocatalytic activity of widely available and cheap organic ammonium and phosphonium salts. Glycerol is selected as a model substrate for preliminary optimization with a library of homogeneous ammonium and phosphonium salts. The nature of the anion dramatically influences the catalytic activity, while the nature of the cation does not impact the reaction. Upon optimization, glycerol carbonate is obtained in 95% conversion and 79% selectivity within 3 min residence time at 180 °C (11 bar) with 3.5 mol% of tetrabutylammonium bromide as the organocatalyst. A straightforward liquid-liquid extraction procedure enables both the purification of glycerol carbonate and the recycling of the homogeneous catalyst. The conditions are amenable to refined and crude bio-based glycerol, although conversions are lower in the latter case. Control experiments suggest that water present in the crude samples induces significant hydrolysis of glycerol carbonate. The reaction conditions are then successfully applied on a wide variety of substrates, affording the corresponding cyclic carbonates in overall good to excellent yields (20 examples, 45-95%). The substrate scope notably encompasses bio-based starting materials such as glycerol ethers and erythritol-derived diols. In-line NMR is featured as a qualitative analytical tool for real-time reaction monitoring. The scalability of this carbonation procedure on glycerol is assessed in a commercial pilot-scale silicon carbide continuous flow reactor of 60 mL internal volume. Glycerol carbonate is obtained in 76% yield, corresponding to a productivity of 13.6 kg per day.
- Gérardy, Romaric,Estager, Julien,Luis, Patricia,Debecker, Damien P.,Monbaliu, Jean-Christophe M.
-
p. 6841 - 6851
(2019/12/24)
-
- PROCESS FOR THE PREPARATION OF GLYCIDOL
-
This invention relates to a process for the preparation of glycidol from the thermal decarboxylation of glycerol carbonate. In one aspect, the present invention provides a process for the preparation of glycidol by thermal decarboxylation of glycerol carbonate, said process comprising the steps of: d)contacting liquid glycerol carbonate with a decarboxylation promotor, having a boiling point of at least 160°Cat atmospheric pressure and consisting essentially of an aliphatic mono-ol, an aliphatic polyol, or mixtures thereof, to form a liquid phase mixture; e)applying heat to the liquid phase mixture formed in step a) to induce thermal decarboxylation of the glycerol carbonate;and f)separating glycidol formed in step b) from the liquid phase mixture by evaporation of glycidol; and wherein the process does not comprise the use of a decarboxylation catalyst.
- -
-
Page/Page column 34-38
(2019/10/23)
-
- Catalytic synthesis of glycerol carbonate from biomass-based glycerol and dimethyl carbonate over Li-La2O3 catalysts
-
The trans-esterification of glycerol and dimethyl carbonate (DMC) for the synthesis of glycerol carbonate was investigated over a series of Li-La2O3 catalysts with different Li contents under mild reaction conditions. Li-La2O3 catalysts were prepared by simple precipitation and impregnation methods, and characterized using ICP, XRD, BET, XPS, CO2-TPD and TEM techniques. It was found that the basicity of La2O3 was obviously changed and the interaction between Li and La2O3 occurred after doping Li component, and the catalytic activity of Li-La2O3 was highly relevant to the strength and content of basic sites on the catalysts. Li doping influenced the crystal phase growth of La2O3, and also changed the exposed crystal planes of the Li-La2O3 catalysts. The highest catalytic performance was obtained over 3.50Li-La2O3 catalyst calcined at 600 °C for 5 h. The glycerol conversion of 94.4% and glycerol carbonate selectivity of 92.1% were obtained over this catalyst under the proper reaction conditions of 85 °C, 3 h, and the molar ratio of glycerol and DMC being 1/3 with using 0.1 g 3.50Li-La2O3 catalyst.
- Li, Yajin,Liu, Jiaxiong,He, Dehua
-
p. 234 - 242
(2018/08/04)
-
- Identifying catalytically active mononuclear peroxoniobate anion of ionic liquids in the epoxidation of olefins
-
The organic carboxylic acid coordinated monomeric peroxoniobate-based ionic liquids (ILs) [TBA][NbO(OH)2(R)] (TBA = tetrabutylammonium; R = lactic acid (LA), glycolic acid (GLY), malic acid (MA)) were prepared and fully characterized by elemental analysis, NMR, IR, Raman, TGA, 93Nb NMR, and HRMS. These IL catalysts exhibited not only high catalytic activity for the epoxidation of olefins under very mild reaction conditions, as the turnover frequency of [TBA][NbO(OH)2(LA)] reached up to 110 h-1, but also satisfactory recyclability in the epoxidation by using only 1 equiv of hydrogen peroxide as an oxidant. Meanwhile, this work revealed that the ILs underwent structural transformation from [NbO(OH)2(R)]- to [Nb(O-O)2(R)]- (R = LA, GLY, MA) in the presence of H2O2 by a subsequent activity evaluation, characterization, and first-principles calculations. Moreover, the organic carboxylic acid coordinated monomeric peroxoniobate-based ILs were investigated using density functional theory (DFT) calculations, which identified that [Nb(O-O)2LA]- was more advantageous than [Nb(O-O)2(OOH)2]- for the epoxidation of olefins. Due to the coordination between the α-hydroxy acids and the monomeric peroxoniobate anions, the functionalized ILs can efficiently catalyze the epoxidation of a wide range of olefins and allylic alcohols under very mild conditions. Additionally, the effect of solvents on the reaction is illustrated. It was found that methanol can lower the epoxidation barriers by forming a hydrogen bond with a peroxo ligand attached to the niobium center.
- Ma, Wenbao,Yuan, Haiyang,Wang, Haifeng,Zhou, Qingqing,Kong, Kang,Li, Difan,Yao, Yefeng,Hou, Zhenshan
-
p. 4645 - 4659
(2018/05/08)
-
- Oxidation method for allyl alcohol
-
The invention relates to an oxidation method for allyl alcohol. The oxidation method comprises a step of, under oxidation reaction conditions, allowing a reaction feed containing allyl alcohol, an oxidizing agent and at least one optional solvent to sequentially flow through a first catalyst bed to an n last catalyst bed, wherein each catalyst bed is filled with at least one titanium silicon molecular sieve; the titanium silicon molecular sieve is at least partially modified; and the modified titanium silicon molecular sieve has undergone modification treatment, and the modification treatment comprises a step of contacting the raw material titanium silicon molecular sieve with a modification solution containing nitric acid and peroxide. The method can prolong the single-pass service life of a catalyst, and can stabilize the conversion rate of raw materials, the effective utilization rate of the oxidizing agent and the selectivity of a target oxidation product at high levels even inthe case of long-period continuous operation.
- -
-
Page/Page column 17-25
(2018/07/30)
-
- Cu-Mn composite oxides: Highly efficient and reusable acid-base catalysts for the carbonylation reaction of glycerol with urea
-
A series of Cu-Mn composite oxides were prepared by co-precipitation. Interestingly, catalysts with varied Cu/Mn molar ratios showed different catalytic performances for glycerol carbonylation. The physicochemical properties of the catalysts are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, temperature-programmed desorption (TPD) of CO2 and NH3 and temperature-programmed reduction (H2-TPR) technology. The results showed that the Cu1.4Mn1.6O4 crystal phase is the active component of the catalysts for the carbonylation of glycerol, this phase can effectively provide Mn4+ and lattice oxygen (O2-), and the existence of the Mn4+-O2- Lewis acid-base pair can promote the formation of glycerol carbonate. Various reaction parameters, such as reaction temperature, time, the molar ratio of glycerol to urea and the amount of catalysts, are studied. Under optimizing reaction conditions, the conversion of glycerol is 91.0% with 99.1% glycerol carbonate selectivity.
- Luo, Wei,Sun, Lei,Yang, Yue,Chen, Yanqiu,Zhou, Zhou,Liu, Junhua,Wang, Fang
-
p. 6468 - 6477
(2019/01/03)
-
- Continuous-Flow Synthesis of (R)-Propylene Carbonate: An Important Intermediate in the Synthesis of Tenofovir
-
(R)-Propylene carbonate is an important intermediate in the synthesis of tenofovir pro-drugs such as tenofovir alafenamide fumarate (TAF) and tenofovir diisoproyl fumarate (TDF). Independent of the pro-drug type, tenofovir presents a chiral secondary hydroxy derivative, which can be obtained directly from (R)-propylene carbonate. Herein, we report our chemo-enzymatic continuous-flow strategy towards (R)-propylene carbonate starting from a very cheap and renewable raw material, glycerol. We were able to synthesize (R)-propylene carbonate in seven continuous-flow steps, starting from glycerol, in good-to-excellent yields (66–93 %) and excellent selectivity (E > 200).
- Suveges, Nicolas S.,Rodriguez, Anderson A.,Diederichs, Carla C.,de Souza, Stefania P.,Le?o, Raquel A. C.,Miranda, Leandro S. M.,Horta, Bruno A. C.,Pedraza, Sérgio F.,de Carvalho, Otavio V.,Pais, Karla C.,Terra, José H. C.,de Souza, Rodrigo O. M. A.
-
supporting information
p. 2931 - 2938
(2018/06/27)
-
- GLYCIDOL SYNTHESIS METHOD
-
The invention relates to a method for obtaining glycidol in a semi-continuous or continuous manner by decarboxylating glycerol carbonate at reduced pressure, at a temperature less than or equal to 130° C. and in the presence of alkoxide catalysts of alkaline metals and alkaline earth metals, metal oxides, mixed metal oxides, metal stannates and mixed metal stannates, all of which optionally supported via SiO2, γ-Al2O3, MgO and ZrO2.
- -
-
Paragraph 0030-0032; 0034-0048
(2018/11/26)
-
- Peroxotantalate-Based Ionic Liquid Catalyzed Epoxidation of Allylic Alcohols with Hydrogen Peroxide
-
The efficient and environmentally benign epoxidation of allylic alcohols has been attained by using new kinds of monomeric peroxotantalate anion-functionalized ionic liquids (ILs=[P4,4,4,n]3[Ta(O)3(η-O2)], P4,4,4,n=quaternary phosphonium cation, n=4, 8, and 14), which have been developed and their structures determined accordingly. This work revealed the parent anions of the ILs underwent structural transformation in the presence of H2O2. The formed active species exhibited excellent catalytic activity, with a turnover frequency for [P4,4,4,4]3[Ta(O)3(η-O2)] of up to 285 h?1, and satisfactory recyclability in the epoxidation of various allylic alcohols under very mild conditions by using only one equivalent of hydrogen peroxide as an oxidant. NMR studies showed the reaction was facilitated through a hydrogen-bonding mechanism, in which the peroxo group (O–O) of the peroxotantalate anion served as the hydrogen-bond acceptor and hydroxyl group in the allylic alcohols served as the hydrogen-bond donor. This work demonstrates that simple monomeric peroxotantalates can catalyze epoxidation of allylic alcohols efficiently.
- Ma, Wenbao,Chen, Chen,Kong, Kang,Dong, Qifeng,Li, Kun,Yuan, Mingming,Li, Difan,Hou, Zhenshan
-
p. 7287 - 7296
(2017/05/31)
-
- A Kinetic Model for the Epoxidation of Allyl Alcohol with Hydrogen Peroxide on Titanium Silicate TS-1
-
The kinetic regularities of the oxidation of allyl alcohol into glycidol in the presence of titanium silicate are studied at varied initial concentrations of the reagents, products, and temperature. The probable mechanism is used as the basis to develop a substantial kinetic model, which adequately describes the obtained experimental data.
- Sulimov,Danov,Ovcharova,Flid,Bruk
-
p. 673 - 678
(2018/03/08)
-
- Synthesis of glycerol carbonate from glycerol and diethyl carbonate over Ce-NiO catalyst: The role of multiphase Ni
-
A series of Ce-NiO catalysts prepared by co-precipitation method were tested for glycerol transesterification with diethyl carbonate (DEC) to produce glycerol carbonate (GC). The microstructural and physicochemical properties of the catalysts were determined by XRD, XPS, SEM, EDX, CO2-TPD, N2-adsorption, FT-IR, and TG-DTG. The results showed that the particle size (100–350 nm) of the Ce-NiO was smaller than that of pure NiO (400–900 nm), suggesting addition of Ce in the catalyst synthesis could lessen the aggregation or facilitate the dispersion of NiO particles. The highest catalyst activity was observed over the Ce-NiO catalyst with Ce/Ni atomic ratio of 0.2 and calcined at 400 °C. 94.14% of glycerol conversion and 90.95% selectivity to GC were obtained over this catalyst under the optimum conditions (5 wt.% catalyst of glycerol, 85 °C, 8 h, glycerol/DEC ratio of 1:3). This catalyst can be reused up to three cycles with a slight decrease in its catalytic activity. It was found the well dispersed NiO particles and the strong basic sites derived from the substitution of Ce4+ by Ni2+ in the CeO2 lattices synergistically promoted the glycerol conversion.
- Wu, Yuanfeng,Song, Xianghai,Cai, Fufeng,Xiao, Guomin
-
p. 360 - 368
(2017/06/05)
-
- Preparation method of glycidol
-
The invention relates to a preparation method of glycidol, belonging to the technical field of synthesis of glycidol. The preparation method of the glycidol comprises the steps: 3-chloro-1,2-propanediol and sodium hydroxide react in an ethanol solution to produce glycidol, NaCl and water; and centrifuging, thin film evaporation, primary short-range distillation and secondary short-range distillation are carried out on the reaction liquid after reaction ends to obtain the glycidol fine product. The preparation method of glycidol is simple in operation, low in cost, high in safety factor and low in reaction temperature, and improves the purity and yield of glycidol.
- -
-
Paragraph 0026; 0027; 0028; 0029; 0030; 0031; 0032-0039
(2017/06/21)
-
- Process for producing dimethyl carbonate
-
The present disclosure relates to a recycling method for producing dimethyl carbonate. The process is unique in that it produces a by-product that can be re-used in the process as a raw material for repeating the process. For example, when the process is directed to synthesizing dimethyl carbonate, glycerol is used as a starting material. Glycerol is also a by-product produced during formation of dimethyl carbonate, and therefore it can be re-used as starting material to generate more dimethyl carbonate.
- -
-
Page/Page column 9
(2017/06/15)
-
- Highly Efficient Epoxidation of Allylic Alcohols with Hydrogen Peroxide Catalyzed by Peroxoniobate-Based Ionic Liquids
-
This work reports new kinds of monomeric peroxoniobate anion functionalized ionic liquids (ILs) designated as [A+][Nb=O(O-O)(OH)2] (A+ = tetrapropylammonium, tetrabutylammonium, or tetrahexylammonium cation), which have been prepared and characterized by elemental analysis, HRMS, NMR, IR, TGA, etc. With hydrogen peroxide as an oxidant, these ILs exhibited excellent catalytic activity and recyclability in the epoxidation of various allylic alcohols under solvent-free and ice bath conditions. Interestingly, subsequent activity tests and catalyst characterization together with first-principles calculations indicated that the parent [Nb=O(O-O)(OH)2]- anion has been oxidized into the anion [Nb(O-O)2(OOH)2]- in the presence of H2O2, which constitutes the real catalytically active species during the reaction; this anion has higher activity in comparison to the analogous peroxotungstate anion. Moreover, the epoxidation process of the substrate (allylic alcohol) catalyzed by [Nb(O-O)2(OOH)2]- was explored at the atomic level by virtue of DFT (density functional theory) calculations, identifying that it is more favorable to occur through a hydrogen bond mechanism, in which the peroxo group of [Nb(O-O)2(OOH)2]- serves as the adsorption site to anchor the substrate OH group by forming a hydrogen bond, while OOH as the active oxygen species attacks the C=C bond in substrates to produce the corresponding epoxide. This is the first example of the highly efficient epoxidation of allylic alcohols using a peroxoniobate anion as a catalyst.
- Chen, Chen,Yuan, Haiyang,Wang, Haifeng,Yao, Yefeng,Ma, Wenbao,Chen, Jizhong,Hou, Zhenshan
-
p. 3354 - 3364
(2016/07/06)
-
- A simplified early stage assessment of process intensification: Glycidol as a value-added product from epichlorohydrin industry wastes
-
The present work deals with the production of glycidol through a new synthetic approach based on the conversion of 2-chloro-1,3-propanediol (β-MCH), a by-product in the epichlorohydrin production plant. β-MCH was converted with high yield (90%) and selectivity (99%) to glycidol using an alcoholic solution of KOH at room temperature in only 30 minutes. A simplified early stage assessment based on the use of the green metrics and a life cycle analysis were adopted in order to evaluate the environmental feasibility of this innovative route if compared with the traditional chain to epichlorohydrin. The waste recovery and the maximization of the overall process efficiency lead to sensible reductions per each indicator considered in the assessment, suggesting the possibility of developing on a full industrial scale. In addition, in order to verify the potentialities behind the substitution of the fossil-based glycidol with the product resulted from the recovery of the β-MCH, a cradle-to-gate analysis and the GREENMOTION tool were adopted.
- Cespi,Cucciniello,Ricciardi,Capacchione,Vassura,Passarini,Proto
-
supporting information
p. 4559 - 4570
(2016/08/18)
-
- Mn(II)-amino acid complexes intercalated in CaAl-layered double hydroxide - Well-characterized, highly efficient, recyclable oxidation catalysts
-
Intercalated composite materials were prepared with CaAl-layered double hydroxide as the host and Mn(II)-amino acid (l-cysteine, l-histidine and l-tyrosine) complex anions as the guest. Two methods (intercalation of the ligand first followed by constructing the complex; preforming the complex first, then introducing it among the layers of the host) and optimization of the auxiliary conditions were performed to arrive at composites having the complex exclusively among the layers. The obtained substances were structurally characterized by powder X-ray diffractometry, mid IR spectroscopy in diffuse reflectance mode and with ATR or photoacoustic detections, and scanning electron microscopy. The structural features of the intercalant (coordination number, coordination sites) were elucidated by classical chemical and energy dispersive X-ray analyses, EPR, X-ray absorption and far IR spectroscopies. Structural models are also given. The catalytic activities, selectivities and recycling abilities of the substances were studied in the oxidation reactions of cyclohexene with peracetic acid and in situ formed iodosylbenzene as oxidants and allylic alcohol with peracetic acid, in the liquid phase. The intercalated substances proved to be efficient and highly selective (with peracetic acid: outstanding epoxide, with iodosylbenzene superior diol selectivities) catalysts with very good recycling abilities.
- Varga, Gábor,Kukovecz, ákos,Kónya, Zoltán,Korecz, László,Muráth, Szabolcs,Csendes, Zita,Peintler, Gábor,Carlson, Stefan,Sipos, Pál,Pálinkó, István
-
p. 125 - 134
(2016/02/18)
-
- Highly efficient epoxidation of cyclohexene with aqueous H2O2 over powdered anion-resin supported solid catalysts
-
Resin supported solid acid catalysts have extended the application of conventional solid acid catalysts in the field of selective oxidations. The present work describes selectively catalytic epoxidation of cyclohexene with aqueous 30% H2O2 over powdered anion-resin supported peroxo phosphotungstic acid heterogeneous catalysts prepared through a simple anion-exchange from powdered chloride-form anion resin without any special pre-exchanged treatment. Among these powdered solid catalysts, anion-exchanged resin D201 supported peroxo phosphotungstic acid exhibits the best activity for the titled reaction to obtain 92.4?mol% conversion and 98.1% selectivity of epoxide, for which D201-PWAR(4) behaves as a truly heterogeneous catalyst. Some factors such as various peroxo phosphotungstic acid concentrations, the oxidants, the solvents, the molar ratios of H2O2/cyclohexene, the catalyst amount, the reaction temperature and time play important roles in controlling the epoxidation.
- Peng,Lu,Ma,Shen,Wei,He,Zhou,Xia
-
p. 393 - 399
(2016/08/02)
-
- Catalytic behaviour of mesoporous metal phosphates in the gas-phase glycerol transformation
-
The catalytic behaviour of mesoporous simple (M = Al, Fe, Co, Mn) and binary (Al/M; M = Fe,V,Ca; molar ratio Al/Fe = 50; Al/V = 2; Al/Ca = 1) metal phosphates, synthesized by an economical gelation method, in the gas-phase glycerol reaction at temperatures between 220 °C and 280 °C, has been investigated. The morphology, textural properties and the acidity by pyridine TPD, of the phosphates were also determined. The activity of the phosphates in the formation of the main reaction product (acrolein) depended not only on their acidity (mainly acid sites of weak-medium strength) but also on the redox sites and morphology exhibited. Thus, the aluminium-vanadium phosphate showed the highest value of yield to acrolein, 62% (equivalent to a productivity of 0.88 gACRgcath) at 280 °C, whereas the amorphous FePO4 and AlPO4 were appreciably more active than the rest of the simple phosphates, exhibiting a high crystalline character. The apparent activation energy values obtained for the acrolein formation ranged between 18 and 91 kJ/mol. Based on the identified products in this study, some possible reactions involved in the glycerol transformation have been suggested.
- Lopez-Pedrajas,Estevez,Navarro,Luna,Bautista
-
-
- METHOD FOR PREPARING GLYCIDOL USING GLYCEROL AND GLYCIDOL OBTAINED THEREBY
-
A method for preparing glycidol using glycerol includes mixing glycerol with urea in the presence of at least one zinc-based catalyst selected from the group consisting of Zn(NO3)2, ZnCl2, ZnO and Zn(OAc)2 under a pressure of 0.5-10 kPa at a temperature of 100-170° C. to obtain glycerol carbonate; filtering the glycerol carbonate mixed with the zinc-based catalyst through an adsorbent including a polymer resin coordinated with amine groups to separate the zinc-based catalyst and glycerol carbonate from each other; and carrying out reaction of the glycerol carbonate separated from the zinc-based catalyst in the presence of an anion alkali metal salt catalyst that is Na, K, Rb, Cs or a mixture thereof containing at least one anion selected from the group consisting of Cl?, Br?, I?, NO3?, NO2? and acetate under a pressure of 0.13-6.67 kPa at a temperature of 140-250° C. to obtain glycidol.
- -
-
Paragraph 0053;0054;0055;0056;0057
(2016/09/26)
-
- A high-purity 3 - methylamino - 1, 2 - propylene glycol green synthetic method
-
The invention provides a green synthetic method of high-purity 3-methylamino-1,2-propandiol. The method comprises the steps of preparation of glycidol and synthesis of 3-methylamino-1,2-propandiol, wherein the preparation of the glycidol comprises the steps of adding chloro-glycerin and sodium methoxide in methanol, reacting and distilling, and the synthesis of the 3-methylamino-1,2-propandiol comprises the steps of testing pressure, charging, performing amination, recycling monomethylamine and distilling. The green synthetic method has the beneficial effects that the purity of a product prepared by using the green synthetic method is high, the impurity and moisture contents are reduced, the product is colorless transparent sticky liquid in appearance, the purity of the product is 99.87 to 99.96%, and the yield is 98.52 to 98.99%; the yield of the glycidol is 92.61 to 93.76%, and the purity is 99.25 to 99.40%; the production cycle is shortened; the effects of safety and environmental friendliness are achieved; secondary reaction such as polymerization and the like almost does not occur; the effects of energy conservation and consumption reduction are obvious.
- -
-
Paragraph 0163-0185
(2017/10/14)
-
- GLYCIDOL PREPARATION
-
This invention relates to an improved one-pot synthetic process for the preparation of glycidol from the reaction of glycerol and dimethyl carbonate. More specifically, the invention relates to a one-pot synthetic process for the preparation of glycidol comprising the reaction of glycerol and dimethyl carbonate in the presence of an ionic liquid catalyst having the formula: [Cat+][X] wherein: [Cat] represents one or more cationic species, and [X] represents one or more anionic species; wherein the reaction is conducted at a temperature of from 100°C to 160°C and wherein the molar ratio of glycerol to dimethylcarbonate is from 1:4 to 1:10.
- -
-
Page/Page column 31
(2015/02/25)
-
- Physicochemical relationships of the synthesis of epoxy compounds
-
Quantitative information on the effect of process parameters on the main relationships of the liquid-phase epoxidation of propylene, allyl chloride, and allyl alcohol with hydrogen peroxide in an organic solvent in the presence of powdered titanium silicalite in a batch reactor was obtained and summarized for the first time. The influence of the solvent amount, reactant ratio, and temperature was examined, and the area of the process parameters ensuring high yields of the epoxy compounds (propylene oxide, epichlorohydrin, and glycidol) was localized.
- Sulimov,Danov,Ovcharova,Ovcharov,Flid
-
-
- Post-synthetic modification of nanoporous Cu3(BTC)2 metal-organic framework via immobilization of a molybdenum complex for selective epoxidation
-
In the present work, nanoporous Cu3(BTC)2 (abbreviated as CuBTC and BTC = benzene-1,3,5-tricarboxylate) metal-organic framework (MOF) was modified in a two-step post-synthetic reaction by covalent attachment of aminopyridine groups followed by the reaction with bis(acetylacetonato) dioxomolybdenum(VI). The prepared molybdenum containing MOF was utilized as a heterogeneous catalyst in the epoxidation of olefins and allylic alcohols. Characterization of the prepared catalyst was performed using Fourier transform infrared, atomic absorption spectroscopies, CHN elemental analysis, powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis and nitrogen adsorption/desorption techniques. The resulting catalyst showed high selectivity and catalytic activity toward the epoxidation reaction. Moreover, the catalyst demonstrated size-selective properties suggested the reaction occurred inside the pores.
- Abednatanzi, Sara,Abbasi, Alireza,Masteri-Farahani, Majid
-
-
- Influence of impurities on the epoxidation of allyl alcohol to glycidol with hydrogen peroxide over titanium silicate TS-1
-
The epoxidation of allyl alcohol to glycidol by hydrogen peroxide over titanium silicate TS-1 ZSM-5 has been studied under conditions relevant for an industrial-scale process. In particular, the effects of different solvents, impurities and some side reactions known to occur due to those impurities have been examined. It was found that certain aldehydes (in particular, acrolein) are especially detrimental to glycidol yield. Conversely, some of the impurities added to the reaction mixture were found to promote the conversion of allyl alcohol. Possible mechanisms for this are discussed.
- Harvey, Luke,Kennedy, Eric,Dlugogorski, Bogdan Z.,Stockenhuber, Michael
-
p. 241 - 246
(2015/05/05)
-
- Preparation of SnO2/graphene nanocomposite and its application to the catalytic epoxidation of alkenes with H2O2
-
The in situ growth of SnO2 nanoparticles on graphene have been achieved via a hydrothermal method and the nanocomposites were used as an efficient catalyst for the epoxidation of alkenes with aqueous hydrogen peroxide in nitrile based systems for the first time. Furthermore, the SnO2/graphene nanocomposites could be readily recovered and reused for at least ten consecutive cycles without significant loss of activity and selectivity.
- Liu, Min,Wang, Xiaozhong,Chen, Yingqi,Dai, Liyan
-
p. 61481 - 61485
(2015/08/03)
-
- Enhanced catalytic activity of nanoporous Cu3(BTC)2 metal-organic framework via immobilization of oxodiperoxo molybdenum complex
-
Molybdenum(vi) oxodiperoxo complex was immobilized into a post synthetically modified Cu3(BTC)2 metal-organic framework (abbreviated as CuBTC MOF, BTC = benzene-1,3,5-tricarboxylate). Characterization of the modified CuBTC MOF by Fourier transform infrared and atomic absorption spectroscopies as well as thermogravimetric and CHN elemental analyses confirmed successful modification of the framework. Powder X-ray diffraction revealed a shift for all peaks to smaller 2 angles during the molybdenum complex attachment as the result of MOF expansion. Nitrogen adsorption/desorption techniques demonstrated a significant decrease in BET surface area and total pore volume during the modification process. The resulting molybdenum-containing MOF showed higher catalytic activity and selectivity than the CuBTC MOF due to the presence of the molybdenum(vi) oxodiperoxo complex.
- Abednatanzi, Sara,Abbasi, Alireza,Masteri-Farahani, Majid
-
p. 5322 - 5328
(2015/07/07)
-
- Oxidovanadium(V) Anchored to Silanol-Functionalized Polyoxotungstates: Molecular Models for Single-Site Silica-Supported Vanadium Catalysts
-
The metalation of two different types of silanol-decorated polyoxotungstates, [XW9O34-x(tBuSiOH)3]3- (X = P, x = 0; X = Sb, x = 1) and [PW10O36(tBuSiOH)2]3-, by Cl3VO or (iPrO)3VO has been achieved. The characterization of the resulting oxidovanadium(V) complexes [XW9O34-x(tBuSiO)3VO]3- (X = P, 3; X = Sb, 3′) and [PW10O36(tBuSiO)2VO(iPrO)]3- (4) has been fully detailed, including X-ray analysis. These compounds are present in monomeric forms and therefore represent original molecular models for tris-grafted and bis-grafted isolated (V=O)3+ species dispersed onto silica. Their ability as precatalysts for the epoxidation of cyclic olefins and allylic alcohols with tert-butyl hydroperoxide (TBHP) has been studied. The results suggested that a confined tris-grafted species, such as 3 or 3′, does not act as an efficient catalyst whereas a more labile bis-grafted species, such as 4, does. To gain a better understanding, we have assessed their suitability for ligand exchange with alcohols and TBHP and performed reaction progress kinetic analysis by monitoring the epoxidation of 3-methyl-2-buten-1-ol by 1H and 51V nuclear magnetic resonance.
- Guillemot, Geoffroy,Matricardi, Edoardo,Chamoreau, Lise-Marie,Thouvenot, René,Proust, Anna
-
p. 7415 - 7423
(2015/12/11)
-
- Synthesis of biodiesel without formation of free glycerol
-
A new approach to the synthesis of biodiesel has been developed on the basis of alcoholysis of a triglyceride in combination with acetalization of glycerol with lower carbonyl compounds or acetals derived therefrom. A model synthesis of biodiesel not involving free glycerol has been accomplished using rapeseed oil and acid catalysts, as well as without a catalyst under generation of ethanol supercritical fluid; in the latter case, monoalkyl glycerol ethers are formed in addition to the expected cyclic ketals.
- Vol'eva,Belostotskaya,Komissarova,Koverzanova,Kurkovskaya,Usmanov,Gumerov
-
p. 915 - 917
(2015/08/25)
-
