scholarly journals Optimization of the Synthesis of Glycerol Derived Monoethers from Glycidol by Means of Heterogeneous Acid Catalysis

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2887 ◽  
Author(s):  
Elisabet Pires ◽  
José García ◽  
Alejandro Leal-Duaso ◽  
José Mayoral ◽  
José García-Peiro ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Room Temperature ◽  
Acid Catalysis ◽  
Catalyst Loading ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Amberlyst 15 ◽  
Green Methodology ◽  
Brønsted And Lewis Acid ◽  
Short Times

We present an efficient and green methodology for the synthesis of glycerol monoethers, starting from glycidol and different alcohols, by means of heterogeneous acid catalysis. A scope of Brønsted and Lewis acid catalysts were applied to the benchmark reaction of glycidol and methanol. The selected catalysts were cationic exchangers, such as Nafion NR50, Dowex 50WX2, Amberlyst 15 and K10-Montmorillonite, both in their protonic form and exchanged with Al(III), Zn(II) and Fe(III). Thus, total conversions were reached in short times by using 1 and 5% mol catalyst loading and room temperature, without the need for excess glycidol or the presence of a solvent. Finally, these conditions and the best catalysts were successfully applied to the reaction of glycidol with several alcohols such as butanol or isopropanol.

scholarly journals Reaction of Glycerol with Trimethyl Orthoformate: Towards the Synthesis of New Glycerol Derivatives

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 534 ◽  
Author(s):  
Roberto Calmanti ◽  
Emanuele Amadio ◽  
Alvise Perosa ◽  
Maurizio Selva
Keyword(s):  
Ionic Liquids ◽  
Lewis Acid ◽  
Synthetic Approach ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Catalyst Free ◽  
Acidic Ionic Liquids ◽  
Brønsted And Lewis Acid ◽  
Trimethyl Orthoformate

The reactivity of glycerol with trimethyl orthoformate is here described with an emphasis on developing a reliable synthetic approach for glycerol valorization. The glycerol based orthoester 4-(dimethoxymethoxy)methyl)-2-methoxy-1,3-dioxolane (3) was synthesized, under catalytic as well as catalyst-free conditions, by taking advantage of the thermodynamically controlled equilibrium between intermediates. Both Brønsted and Lewis acid catalysts accelerated the attainment of such an equilibrium, particularly Brønsted acidic ionic liquids BSMImHSO4 and BSMImBr were the most effective compounds for this reaction. The kinetic profiles allowed the proposal of a mechanism that accounts for the selectivity of the reaction.

Friedel–Crafts Chemistry. Part 48. Concise Synthesis of Condensed Azaheterocyclic [1,8]naphthyridinones, Azepino-, Azocino-, and Azoninoquinoline Systems via Friedel–Crafts Ring Closures

2017 ◽  
Vol 70 (10) ◽  
pp. 1082 ◽  
Author(s):  
Hassan A. K. Abd El-Aal
Keyword(s):  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Acid Catalyzed ◽  
Keto Analogues ◽  
Brønsted And Lewis Acid

Unprecedented construction of a novel series of quinoline heteropolycycles (tetracyclic keto-analogues of [1,8]naphthyridinones, azepino-, azocino- and azonino[2,3-b]quinolinones systems) 10a–i by Friedel–Crafts cycliacylation reactions is described. Starting heterocyclic acids precursors 3a–i were prepared from easily accessible 2-chloroquinoline-3-carbaldehyde 1 via a three different synthetic pathways. Acid-catalyzed ring closures of the resulting tosylated acids were achieved under the influence of both Brønsted and Lewis acid catalysts. The present strategy enables a straightforward synthesis to fused tetracyclic quinolinone skeletons as demonstrated by concise and atom-economical syntheses.

Hydrophobic microporous and mesoporous oxides as Brønsted and Lewis acid catalysts for biomass conversion in liquid water

2014 ◽  
Vol 4 (9) ◽  
pp. 2877-2886 ◽  
Author(s):  
Rajamani Gounder
Keyword(s):  
Lewis Acid ◽  
Liquid Water ◽  
Biomass Conversion ◽  
Acid Catalysts ◽  
Hydrophobic Surfaces ◽  
Lewis Acid Catalysts ◽  
Mesoporous Silicates ◽  
Catalytic Reactivity ◽  
Brønsted And Lewis Acid ◽  
Mesoporous Oxides

Microporous and mesoporous silicates with internal or external hydrophobic surfaces show differences in catalytic reactivity and stability in liquid water.

scholarly journals Boron-Based Lewis Acid Catalysis: Challenges and Perspectives

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Valeria Nori ◽  
Fabio Pesciaioli ◽  
Arianna Sinibaldi ◽  
Giuliana Giorgianni ◽  
Armando Carlone
Keyword(s):  
Organic Synthesis ◽  
Lewis Acid ◽  
Gold Standard ◽  
Lewis Acids ◽  
Acid Catalysis ◽  
Acid Catalysts ◽  
Chemical Transformations ◽  
Lewis Acid Catalysis ◽  
Lewis Acid Catalysts ◽  
Better Than

In the last two decades, boron-based catalysis has been gaining increasing traction in the field of organic synthesis. The use of halogenated triarylboranes as main group Lewis acid catalysts is an attractive strategy. It has been applied in a growing number of transformations over the years, where they may perform comparably or even better than the gold standard catalysts. This review discusses methods of borane synthesis and cutting-edge boron-based Lewis acid catalysis, focusing especially on tris(pentafluorophenyl)-borane [B(C6F5)3], and other halogenated triarylboranes, highlighting how boron Lewis acids employed as catalysts can unlock a plethora of unprecedented chemical transformations or improve the efficiency of existing reactions.

Metal Benzenesulfonates/Acetic Acid Mixtures as Novel Catalytic Systems: Application to the Protection of a Hydroxyl Group

2010 ◽  
Vol 65 (11) ◽  
pp. 1349-1352 ◽  
Author(s):  
Min Wang ◽  
Jingjing Gao ◽  
Zhiguo Song
Keyword(s):  
Acetic Acid ◽  
Synergistic Effect ◽  
Lewis Acid ◽  
Room Temperature ◽  
Acid Catalysis ◽  
Hydroxyl Group ◽  
Catalytic Systems ◽  
Double Activation ◽  
High Yields ◽  
Brønsted And Lewis Acid

A surprising synergistic effect has been discovered in mixtures of metal benzenesulfonates (Co, Al, Ni, Zn, Cd, Pr, La, Cu, Mn) and acetic acid, leading to active catalytic systems for the tetrahydropyranylation of alcohols and phenols to produce tetrahydropyranyl ethers. All reactions proceed mildly and efficiently with moderate to high yields at room temperature without solvent. After the reaction, the metal benzenesulfonate can be easily recovered and reused many times. The efficiency of these systems might result from the “double activation” by Brønsted and Lewis acid catalysis.

Homogeneously-acid catalyzed oligomerization of glycerol

2015 ◽  
Vol 17 (8) ◽  
pp. 4307-4314 ◽  
Author(s):  
N. Sayoud ◽  
K. De Oliveira Vigier ◽  
Tatiana Cucu ◽  
Bruno De Meulenaer ◽  
Zhaoyu Fan ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Average Degree ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Acid Catalyzed ◽  
Optimized Conditions ◽  
Brønsted And Lewis Acid

Here, we report the oligomerization of glycerol in the presence of various Brønsted and Lewis acid catalysts. Under optimized conditions, oligoglycerols with an average degree of oligomerization of 3.4 were selectively obtained at 80% conversion of glycerol.

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