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.

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.

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.

scholarly journals Electrophilic bis-fluorophosphonium dications: Lewis acid catalysts from diphosphines

2015 ◽  
Vol 6 (3) ◽  
pp. 2016-2021 ◽  
Author(s):  
Michael H. Holthausen ◽  
Rashi R. Hiranandani ◽  
Douglas W. Stephan
Keyword(s):  
Lewis Acid ◽  
Lewis Acidity ◽  
Spatial Proximity ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Acid Catalyzed

A series of electrophilic bis-fluorophosphonium dications dervied from diphosphines with naphthalene- and (oligo)methylene-linkers is presented. The resulting Lewis acidity is demonstrated to depend on the spatial proximity between the P moieties as evidenced in several Lewis acid catalyzed transformations.

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 Recent Advances in the Brønsted/Lewis Acid Catalyzed Conversion of Glucose to HMF and Lactic Acid: Pathways toward Bio-Based Plastics

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1395
Author(s):  
Cristina Megías-Sayago ◽  
Sara Navarro-Jaén ◽  
Fabien Drault ◽  
Svetlana Ivanova
Keyword(s):  
Lactic Acid ◽  
Lewis Acid ◽  
Catalyst Design ◽  
Added Value ◽  
Present Review ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Starting Point ◽  
Acid Catalyzed ◽  
Multifunctional Catalyst

One of the most trending topics in catalysis recently is the use of renewable sources and/or non-waste technologies to generate products with high added value. That is why, the present review resumes the advances in catalyst design for biomass chemical valorization. The variety of involved reactions and functionality of obtained molecules requires the use of multifunctional catalyst able to increase the efficiency and selectivity of the selected process. The use of glucose as platform molecule is proposed here and its use as starting point for biobased plastics production is revised with special attention paid to the proposed tandem Bronsted/Lewis acid catalysts.

Dehydrobromination of 1,1-diaryl-1,2-dibromoalkanes catalyzed by iron and iron bromides. An ion-pair-mediated reaction?

1995 ◽  
Vol 73 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Angela R. Suárez ◽  
Alejandra G. Suárez ◽  
Sandra E. Martín ◽  
María R. Mazzieri
Keyword(s):  
Lewis Acid ◽  
Ion Pair ◽  
Lewis Base ◽  
Experimental Results ◽  
Chemical Hardness ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Phenyl Rings ◽  
Acid Catalyzed

The participation of ion-paired Lewis acid/Lewis base in the dehydrohalogenations of 1,2-dibromo-1,1 -diarylalkanes catalyzed by Fe0 and by Fe(II) and Fe(III) bromides was investigated. The reactivities of the catalyst employed were correlated with their chemical hardness. The influence of para substituents on the phenyl rings of the substrates and the results obtained in Lewis-acid-catalyzed and thermal dehydrobromination of the same compounds were compared. The experimental results could not be explained in terms of a Lewis-acid-catalyzed dehydrobromination. Keywords: dehydrohalogenation, bromoalkanes, Lewis acid catalysts, ion-pair mechanism.

Synthesis and Applications of Chiral Bicyclic Bisborane Catalysts

Synthesis ◽  
2021 ◽  
Author(s):  
Zhao-Ying Yang ◽  
Ming Zhang ◽  
Xiao-Chen Wang
Keyword(s):  
Transition Metal ◽  
Lewis Acid ◽  
Asymmetric Hydrogenation ◽  
Acid Catalysts ◽  
Frustrated Lewis Pairs ◽  
Lewis Acid Catalysts ◽  
Lewis Bases ◽  
Metal Free ◽  
Hydrogenation Reactions ◽  
Acid Catalyzed

The development of chiral borane Lewis acid catalysts opened the door for transition-metal-free catalyzed asymmetric organic reactions. Herein, we have summarized our work on the preparation of two classes of novel chiral bicyclic bisborane Lewis acid catalysts derived from C2-symmetric [3.3.0] dienes and [4.4] dienes, respectively. These catalysts not only form frustrated Lewis pairs with Lewis bases to catalyze asymmetric hydrogenation reactions but also activate Lewis basic functional groups in traditional Lewis acid catalyzed asymmetric reactions.

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.

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