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You searched for: Subject term catalysts Remove constraint Subject term: catalysts Subject term dioxane Remove constraint Subject term: dioxane Text availability Citation in PubAg Remove constraint Text availability: Citation in PubAg
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1. A chiral phosphoric acid catalyst for asymmetric construction of 1,3-dioxanes

Author:
Akira Matsumoto; Keisuke Asano; Seijiro Matsubara
Source:
Chemical communications 2015 v.51 no.58 pp. 11693-11696
ISSN:
1364-548X
Subject:
catalysts; chemical reactions; dioxane; enantioselectivity; phosphoric acid; polyketides
Abstract:
... A novel method of enantioselective 1,3-dioxane construction via a hemiacetalization/intramolecular oxy-Michael addition cascade by a chiral phosphoric acid catalyst was developed. The product was successfully transformed into an optically active 1,3-polyol motif, indicating that the proposed reaction can provide useful chiral building blocks for the de novo synthesis of polyketides. ...
DOI:
10.1039/c5cc04124d

2. A green method of adipic acid synthesis: organic solvent- and halide-free oxidation of cycloalkanones with 30% hydrogen peroxide

Author:
Yoko Usui; Kazuhiko Sato
Source:
Green chemistry 2003 v.5 no.4 pp. 373-375
ISSN:
1463-9270
Subject:
adipic acid; alcohols; catalysts; cyclohexanones; dioxane; green chemistry; hydrogen peroxide; oxidation; solvents
Abstract:
... Cyclohexanone and cyclohexanol are oxidized to adipic acid in high yield with aqueous 30% H₂O₂ in the presence of H₂WO₄ as a catalyst under organic solvent- and halide-free conditions. It is important that no solvent is used in order to achieve high reactivity in this heterogeneous reaction. The use of t-butyl alcohol or dioxane as a solvent (homogeneous conditions) significantly decreases the yie ...
DOI:
10.1039/b305847f

3. A new route to α,ω-diamines from hydrogenation of dicarboxylic acids and their derivatives in the presence of amines

Author:
Yiping Shi; Paul C. J. KamerCurrent address: Bioinspired Homo- & Heterogeneous catalysis, Leibniz Institute for Catalysis, Albert-Einstein-Straße 29 a, 18059 Rostock, Germany.; David J. Cole-Hamilton
Source:
Green chemistry 2017 v.19 no.22 pp. 5460-5466
ISSN:
1463-9270
Subject:
amides; biomass; catalysts; diamines; dicarboxylic acids; dioxane; esters; glycols; green chemistry; hydrogenation; polymers; ruthenium; solvents; tetrahydrofuran; wastes
Abstract:
... A new and selective route for the synthesis of polymer precursors, primary diamines or N-substituted diamines, from dicarboxylic acids, diesters, diamides and diols using a Ru/triphos catalyst is reported. Excellent conversions and yields are obtained under optimised reaction conditions. The reactions worked very well using 1,4-dioxane as solvent, but the greener solvent, 2-methyl tetrahydrofuran, ...
DOI:
10.1039/c7gc02838e

4. A novel one-pot process for the preparation of linear and hyperbranched polycarbonates of various diols and triols using dimethyl carbonate

Author:
Jingjiang Sun; Kamal Ibrahim Aly; Dirk Kuckling
Source:
RSC advances 2017 v.7 no.21 pp. 12550-12560
ISSN:
2046-2069
Subject:
atmospheric pressure; byproducts; carbonates; catalysts; condensation reactions; dioxane; glycols; lithium; methanol; molecular weight; polymerization; polymers; sieves; toxicity; transesterification; wastes
Abstract:
... A new eco-friendly strategy for the preparation of linear and hyperbranched polycarbonates was developed. Our work referred to a one-pot condensation polymerization of various alcohols (diols and triols) with equivalent amounts of eco-friendly dimethyl carbonate (DMC) at 120 °C, atmospheric pressure and in 1,4-dioxane solution using 4-dimethylaminopyridine (DMAP) or lithium acetylacetonate (LiAcac ...
DOI:
10.1039/c7ra01317e

5. ATRP grafting of poly(N,N‐dimethylamino‐2‐ethyl methacrylate) onto the fatty‐acid‐modified agarose backbone via the “grafting‐from” technique

Author:
Farzad Seidi; Armin Zarei
Source:
Stärke = 2016 v.68 no.7-8 pp. 644-650
ISSN:
0038-9056
Subject:
Fourier transform infrared spectroscopy; acylation; agarose; aggregation behavior; catalysts; composite polymers; dioxane; pH; palmitates; polymerization; solubility; temperature
Abstract:
... In this research, we prepared hydrophobically modified agarose‐g‐poly(N,N‐dimethylamino‐2‐ethyl methacrylate) via the “grafting from” ATRP technique. First, agarose was hydrophobically modified by acylation of some of its OH groups with palmitoyl chloride. Then, the macroinitiator for ATRP was prepared by acylation of some remaining hydroxyl groups of agarose palmitate with 2‐bromopropionyl bromid ...
DOI:
10.1002/star.201500352

6. Acetalization of glycerol and benzaldehyde to synthesize biofuel additives using SO42-/CeO2–ZrO2 catalyst

Author:
Rajeswari M. Kulkarni; N. Arvind
Source:
Heliyon 2021 v.7 no.1 pp. e06018
ISSN:
2405-8440
Subject:
acidity; benzaldehyde; biofuels; catalysts; combustion; desorption; dioxane; glycerol; hexane; kinetics; pentanols; porosity; temperature; thermal stability; toluene
Abstract:
... Synthesis of 1,3- dioxane and 1,3-dioxolane, using sulfated CeO₂–ZrO₂ catalyst for acetalization of glycerol with benzaldehyde, is the focus of present work. SO₄²⁻/CeO₂–ZrO₂ catalyst was synthesized using combustion method. Experiments were carried out to analyze the effect of various solvents (n-hexane, toluene, tert-butyl alcohol, pentanol), molar ratios (1:3, 1:5, 1:7), catalyst loadings (3 wt% ...
DOI:
10.1016/j.heliyon.2021.e06018

7. Acidolysis of a lignin model: Investigation of heterogeneous catalysis using Montmorillonite clay

Author:
Bouxin, Florent; Baumberger, Stéphanie; Pollet, Brigitte; Haudrechy, Arnaud; Renault, Jean-Hugues; Dole, Patrice
Source:
Bioresource technology 2010 v.101 no.2 pp. 736-744
ISSN:
0960-8524
Subject:
dioxane; catalysts; high performance liquid chromatography; hydrochloric acid; gel chromatography; solvents; montmorillonite; acid hydrolysis; mass spectrometry; lignin
Abstract:
... The use of heterogeneous conditions involving Montmorillonite K10 clay was investigated as a mild alternative to homogeneous acidolysis of a lignin model. Guaiacyl Dehydrogenation Oligomers (DHOs) synthesized by horseradish peroxidase were selected as starting material. Hydrolysis products were analyzed by gel permeation chromatography and by HPLC/mass spectrometry. Several experimental parameters ...
DOI:
10.1016/j.biortech.2009.08.037
PubMed:
19747820

8. Activity and Stability of Chloroperoxidase in the Presence of Small Quantities of Polysaccharides: A Catalytically Favorable Conformation Was Induced

Author:
Chaonan Li; Limin Wang; Yucheng Jiang; Mancheng Hu; Shuni Li; Quanguo Zhai
Source:
Applied biochemistry and biotechnology 2011 v.165 no.7-8 pp. 1691-1707
ISSN:
0273-2289
Subject:
additives; biotransformation; catalysts; dimethyl sulfoxide; dioxane; enzyme stability; enzymes; fluorescence; industrial applications; methanol; pollutants; solvents; starch; temperature
Abstract:
... Chloroperoxidase (CPO) is thought to be the most versatile heme-containing enzyme with enormous applications in organic synthesis, biotransformation, pharmaceutical production, and detoxification of environmental pollutants. Any improvement in the stability of this enzyme will greatly enhance its application in the mentioned areas. In the present study, the effects of three polysaccharides (solubl ...
DOI:
10.1007/s12010-011-9388-7
PubMed:
21947712

9. An innovative synthesis pathway to benzodioxanes: the peculiar reactivity of glycerol carbonate and catechol

Author:
T. Tabanelli; C. Giliberti; R. Mazzoni; R. Cucciniello; F. Cavani
Source:
Green chemistry 2019 v.21 no.2 pp. 329-338
ISSN:
1463-9270
Subject:
alkylation agents; carbonates; catalysts; catechol; dioxane; gas chromatography-mass spectrometry; glycerol; green chemistry; isomers; magnesium oxide; nuclear magnetic resonance spectroscopy; odors; pharmaceutical industry; solvents
Abstract:
... A peculiar reactivity of glycerol carbonate (GlyC) as an innovative and highly reactive alkylating agent for phenolic compounds is investigated in this article. In particular, 2-hydroxymethyl-1,4-benzodioxane (HMB), a key intermediate for the pharmaceutical industry, has been selectively synthesized by the reaction of a slight excess of GlyC with catechol in the presence of a basic catalyst (NaOCH ...
DOI:
10.1039/c8gc02811g

10. Bimetallic Ru–Mo Phosphide Catalysts for the Hydrogenation of CO₂ to Methanol

Author:
Feiyang Geng; Yolanda Bonita; Varsha Jain; Matthew Magiera; Neeraj Rai; Jason C. Hicks
Source:
Industrial & engineering chemistry process design and development 2020 v.59 no.15 pp. 6931-6943
ISSN:
1520-5045
Subject:
X-ray photoelectron spectroscopy; carbon dioxide; catalysts; density functional theory; desorption; dioxane; hydrogen; hydrogenation; methanol; molybdenum; phosphides; ruthenium
Abstract:
... Metal phosphides have been investigated as promising catalysts for many hydrogenation reactions, including CO₂ reduction. Due to the vast compositional space available to discover active and selective transition metal phosphide catalysts for energy-related reactions, we report a variety of Mo-based and Ru-based phosphide catalysts for the hydrogenation of CO₂ to methanol in 1,4-dioxane (200 °C, 1 ...
DOI:
10.1021/acs.iecr.9b06937

11. Binding mode of dihydroquinazolinones with lysozyme and its antifungal activity against Aspergillus species

Author:
K. Hemalatha; G. Madhumitha; Lokesh Ravi; V. Gopiesh Khanna; Naif Abdullah Al-Dhabi; Mariadhas Valan Arasu
Source:
Journal of photochemistry and photobiology 2016 v.161 pp. 71-79
ISSN:
1011-1344
Subject:
Aspergillus fumigatus; Aspergillus niger; active ingredients; antifungal properties; aspergillosis; catalysts; dioxane; fungi; lysozyme; molecular models; palladium; patients; potassium bicarbonate; spectral analysis
Abstract:
... Aspergillosis is one of the infectious fungal diseases affecting mainly the immunocompromised patients. The scarcity of the antifungal targets has identified the importance of N-myristoyl transferase (NMT) in the regulation of fungal pathway. The dihydroquinazolinone molecules were designed on the basis of fragments responsible for binding with the target enzyme. The aryl halide, 1(a-g), aryl boro ...
DOI:
10.1016/j.jphotobiol.2016.05.005

12. Catalyst Support and Solvent Effects during Lignin Depolymerization and Hydrodeoxygenation

Author:
Florent Héroguel; Xuan Trung Nguyen; Jeremy S. Luterbacher
Source:
ACS sustainable chemistry & engineering 2019 v.7 no.20 pp. 16952-16958
ISSN:
2168-0485
Subject:
activated carbon; active sites; adsorption; catalysts; catalytic activity; cyclohexanes; depolymerization; dioxane; iso-octanes; lignin; solubility; solvents; titanium dioxide
Abstract:
... We studied and compared the hydrodeoxygenation (HDO) and depolymerization of aldehyde-stabilized lignin and 4-propylguaiacol (PG), a model lignin monomer. We demonstrated by liquid phase adsorption that PG HDO catalyzed by Ru/C can be achieved in isooctane but not in 1,4-dioxane due to competitive solvent binding to the active sites. Unfortunately, alkanes cannot be used as solvents for real ligni ...
DOI:
10.1021/acssuschemeng.9b03843

13. Catalytic C–H Activation/C–C Coupling Reaction: DFT Studies on the Mechanism, Solvent Effect, and Role of Additive

Author:
Zhang Lei; Fang De-Cai
Source:
Journal of organic chemistry 2013 v.78 no.6 pp. 2405-2412
ISSN:
1520-6904
Subject:
carbon-hydrogen bond activation; catalysts; dioxane; methodology; organic chemistry; regioselectivity; silver; solvents
Abstract:
... A series of density functional theory (DFT) experiments, employing the B3LYP+IDSCRF/BS1 and B3LYP+IDSCRF/DZVP methods, have been carried out for the Pd(OAc)₂-catalyzed enamide–siloxane C–H activation/C–C coupling reactions. The results reveal that there are four processes, namely C–H activation, transmetalation (TM), reductive elimination (RE), and separation of product (SP) and recycling of catal ...
DOI:
10.1021/jo302567s

14. Catalytic Hydrogenation of Renewable Levulinic Acid to γ-Valerolactone: Insights into the Influence of Feed Impurities on Catalyst Performance in Batch and Flow Reactors

Author:
Homer C. Genuino; Henk H. van de Bovenkamp; Erwin Wilbers; Jozef G. M. Winkelman; Andrey Goryachev; Jan P. Hofmann; Emiel J. M. Hensen; Bert M. Weckhuysen; Pieter C. A. Bruijnincx; Hero J. Heeres
Source:
ACS sustainable chemistry & engineering 2020 v.8 no.15 pp. 5903-5919
ISSN:
2168-0485
Subject:
adsorption; carbon monoxide; catalysts; catalytic activity; cysteine; dioxane; formic acid; furfural; hydrogenation; hydroxymethylfurfural; lactones; levulinic acid; methionine; ruthenium; solvents; sulfuric acid; surface area; titanium; titanium dioxide; zirconium oxide
Abstract:
... γ-Valerolactone (GVL) is readily obtained by the hydrogenation of levulinic acid (LA) and is considered a sustainable platform chemical for the production of biobased chemicals. Herein, the performance and stability of Ru-based catalysts (1 wt % Ru) supported on TiO₂ (P25) and ZrO₂ (monoclinic) for LA hydrogenation to GVL is investigated in the liquid phase in batch and continuous-flow reactors us ...
DOI:
10.1021/acssuschemeng.9b07678

15. Catalytic behaviour of TiO₂–ZrO₂ binary oxide synthesized by sol–gel process for glucose conversion to 5-hydroxymethylfurfural

Author:
Luqman Atanda; Adib Silahua; Swathi Mukundan; Abhijit Shrotri; Gilberto Torres-Torres; Jorge Beltramini
Source:
RSC advances 2015 v.5 no.98 pp. 80346-80352
ISSN:
2046-2069
Subject:
catalysts; catalytic activity; dioxane; glucose; hydroxymethylfurfural; oxides; polymers; sol-gel processing; solvents
Abstract:
... The catalytic application of as-synthesized TiO₂–ZrO₂ binary oxides was examined for the conversion of glucose to produce 5-hydroxymethylfurfural (HMF). Highest HMF yield (74%) at glucose concentration of 5 wt% was obtained with TiO₂–ZrO₂ (1/1) and Amberlyst 70 catalyst system in a water–THF biphasic reaction system. Notably, a much higher HMF yield (86%) was achieved when the organic phase of the ...
DOI:
10.1039/c5ra15739k

16. Catalytic depolymerisation of suberin rich biomass with precious metal catalysts

Author:
Christopher S. McCallum; Nicholas Strachan; Stephen C. Bennett; W. Graham Forsythe; Mark D. Garrett; Christopher Hardacre; Kevin Morgan; Gary N. Sheldrake
Source:
Green chemistry 2018 v.20 no.12 pp. 2702-2705
ISSN:
1463-9270
Subject:
biofuels; biomass; catalysts; cork; depolymerization; dioxane; green chemistry; lipids; solvents; suberin; tetrahydrofuran
Abstract:
... Hydrogenolysis of cork has been examined using a range of precious metal catalysts studying the effect of the support, added base and solvent used. The addition of a catalyst and a base resulted in a bio-oil increase of 9.3–158% compared to when no catalyst was used along with an increase in the lipid yield of 113–258%. The change in the solvent to 2-methyl tetrahydrofuran from the original dioxan ...
DOI:
10.1039/c8gc00605a

17. Catalytic transfer hydrogenation of biomass-derived furfural to furfuryl alcohol over in-situ prepared nano Cu-Pd/C catalyst using formic acid as hydrogen source

Author:
Juan Du; Jiaren Zhang; Yong Sun; Wenlong Jia; Zhihao Si; He Gao; Xing Tang; Xianhai Zeng; Tingzhou Lei; Shijie Liu; Lu Lin
Source:
Journal of catalysis 2018 v.368 pp. 69-78
ISSN:
0021-9517
Subject:
adsorption; alloys; catalysts; copper; cupric oxide; dioxane; formic acid; furfural; furfuryl alcohol; hydrogen; hydrogenation; leaching; palladium
Abstract:
... Catalytic transfer hydrogenation (CTH) of bio-derived furfural (FF) to furfuryl alcohol (FFA) was performed using the physically mixed CuO-Pd/C as catalyst and formic acid (FA) as hydrogen donor. The evolution investigation of Cu showed the precursor CuO firstly dissolved into Cu2+ by FA and then formed coordination polymer-copper(II), which uniformly dispersed in reaction solution of 1, 4-dioxane ...
DOI:
10.1016/j.jcat.2018.09.025

18. Construction of solvent-dependent self-assembled porous Ni(ii)-coordinated frameworks as effective catalysts for chemical transformation of CO₂

Author:
Zhen Zhou; Lu Yang; Yefei Wang; Cheng He; Tao Liu; Chunying Duan
Source:
RSC advances 2016 v.6 no.109 pp. 108010-108016
ISSN:
2046-2069
Subject:
X-ray diffraction; active sites; carbon dioxide; carbonates; catalysts; catalytic activity; cycloaddition reactions; dimethyl sulfoxide; dioxane; epoxides; ethanol; moieties; nickel; solvents; wastes
Abstract:
... Coordinated frameworks having large pores can accommodate organic molecules and adsorb gas, such as waste carbon dioxide, to transform into valuable chemical products. By incorporating a tetraphenylethylene moiety as the four-point connected node, herein, two types of Ni(ii)-based coordinated frameworks have been solvothermally synthesized via solvent driven self-assembly and structurally characte ...
DOI:
10.1039/c6ra22971a

19. Convenient synthesis of s-triazine based urea derivatives via a palladium catalyzed C–N coupling reaction

Author:
Jignesh P. Dalvadi; Poojan K. Patel; Kishor H. Chikhalia
Source:
RSC advances 2013 v.3 no.23 pp. 8960-8966
ISSN:
2046-2069
Subject:
catalysts; catalytic activity; dioxane; nitrogen; palladium; urea
Abstract:
... A series of s-triazine based urea derivatives have been synthesized by a palladium catalyzed C–N coupling reaction. The synthetic route developed involves the Pd-catalyzed C–N coupling reaction from 2-chloro-4,6-disubstituted-s-triazine with a variety of ureas using the catalyst system Pd₂(dba)₃, Xantphos and Cs₂CO₃ as the base in the presence of 1,4-dioxane under a nitrogen atmosphere. Under thes ...
DOI:
10.1039/c3ra40490k

20. Conversion of platform chemical glycerol to cyclic acetals promoted by acidic ionic liquids

Author:
Bo Wang; Yue Shen; Jiankui Sun; Feng Xu; Runcang Sun
Source:
RSC advances 2014 v.4 no.36 pp. 18917-18923
ISSN:
2046-2069
Subject:
ambient temperature; benzaldehyde; biomass; catalysts; chemistry; dioxane; distillation; glycerol; ionic liquids; nuclear magnetic resonance spectroscopy; sulfates
Abstract:
... The condensation of glycerol, a platform chemical from renewable materials, with benzaldehyde to generate cyclic acetals was investigated using acidic ionic liquid as catalyst. Evidence was presented that the product mixture of 4-hydroxymethyl-2-phenyl-1,3-dioxolane and 5-hydroxyl-2-phenyl-1,3-dioxane, with cis and trans two stereo-isomers for each one identified by ¹H NMR were obtained. Further m ...
DOI:
10.1039/c4ra01443j