scholarly journals MgAl-Layered Double Hydroxide Solid Base Catalysts for Henry Reaction: A Green Protocol

Catalysts ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 133 ◽  
Author(s):  
Magda Abdellattif ◽  
Mohamed Mokhtar
Keyword(s):  
Layered Double Hydroxide ◽  
Solid Base ◽  
Henry Reaction ◽  
Green Protocol ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Double Hydroxide

scholarly journals MgAl-Layered Double Hydroxide Solid Base Catalysts for Henry Reaction: A Green Protocol

2018 ◽  
Author(s):  
Magda H. Abdellattif ◽  
Mohamed Mokhtar
Keyword(s):  
Layered Double Hydroxide ◽  
Catalytic Efficiency ◽  
Mesoporous Structure ◽  
Product Yield ◽  
Solid Catalyst ◽  
Solid Base ◽  
Henry Reaction ◽  
Test Reaction ◽  
Green Protocol ◽  
Double Hydroxide

A series of MgAl-layered double hydroxide (MgAl-HT), the calcined form at 500oC (MgAlOx) and the re-hydrated one at 25oC (MgAl-HT-RH) were synthesized. Physicochemical properties of the catalysts were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM). Surface area of the as-synthesized, calcined and re-hydrated catalysts was determined by N2 physisorption at -196oC. CO2-teperature programmed desorption (CO2-TPD) was applied to determine the basic sites of catalysts. The catalytic test reaction was carried out using benzaldehyde and their derivatives with nitromethane and their derivatives. The Henry products (1-15) were obtained in a very good yield using MgAl-HT-RH catalyst either by conventional method at 90oC in liquid phase, or under microwave irradiation method. The mesoporous structure and basic nature of re-hydrated solid catalyst were responsible for their superior catalytic efficiency. The robust nature was determined by using the same catalyst for five times, where the product % yield was almost unchanged significantly.

scholarly journals Layered double hydroxide anchored ionic liquids as amphiphilic heterogeneous catalysts for the Knoevenagel condensation reaction

2018 ◽  
Vol 47 (9) ◽  
pp. 3059-3067 ◽  
Author(s):  
Tengfei Li ◽  
Wei Zhang ◽  
Wei Chen ◽  
Haralampos N. Miras ◽  
Yu-Fei Song
Keyword(s):  
Heterogeneous Catalysts ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Reaction ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Excellent Activity ◽  
Knoevenagel Condensation Reaction ◽  
Double Hydroxide

In this paper, three solid base catalysts of LDH-IL-Cn (n = 4, 8, 12) were synthesized by adopting an exfoliation/assembly approach. The as-prepared catalyst showed excellent activity and selectivity for the Knoevenagel reaction in aqueous solution.

scholarly journals Alkali-Free Zn–Al Layered Double Hydroxide Catalysts for Triglyceride Transesterification

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 667 ◽  
Author(s):  
Nazrizawati Tajuddin ◽  
Jinesh Manayil ◽  
Mark Isaacs ◽  
Christopher Parlett ◽  
Adam Lee ◽  
...  
Keyword(s):  
Vapour Phase ◽  
Solid Base ◽  
Phase Reconstruction ◽  
Wide Composition Range ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Synthetic Routes ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Cold Liquid

Zn–Al layered double hydroxides (LDHs) of general formula [Zn2+(1−x)Al3+x(OH)2]x+(CO32−)x/2·yH2O are promising solid base catalysts for the transesterification of lipids to biofuels. However, conventional synthetic routes employ alkali hydroxide/carbonate precipitants which may contaminate the final LDH catalyst and biofuel. The use of (NH3)2CO3 and NH3OH as precipitants affords alkali-free Zn–Al-LDHs spanning a wide composition range. The hydrothermal reconstruction of calcined Zn–Al-LDHs offers superior solid basicity and catalytic activity for the transesterification of C4–C18 triglycerides with methanol, compared with cold liquid phase or vapour phase reconstruction. Hydrothermally activated Zn3.3–Al-LDH was stable towards leaching during transesterification.

scholarly journals Ketone Formation via Decarboxylation Reactions of Fatty Acids Using Solid Hydroxide/Oxide Catalysts

Inorganics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 121 ◽  
Author(s):  
Benjamin Smith ◽  
Li Li ◽  
Diego Perera-Solis ◽  
Louise Gildea ◽  
Vladimir Zholobenko ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Mixed Metal Oxide ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Oxide Phases ◽  
Synthetic Routes ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Ketone Formation

A sustainable route to ketones is described where stearone is produced via ketonic decarboxylation of stearic acid mediated by solid base catalysts in yields of up to 97%, at 250 °C. A range of Mg/Al layered double hydroxide (LDH) and mixed metal oxide (MMO) solid base catalysts were prepared with Mg/Al ratios of between 2 and 6 via two synthetic routes, co-precipitation and co-hydration, with each material tested for their catalytic performance. For a given Mg/Al ratio, the LDH and MMO materials showed similar reactivity, with no correlation to the method of preparation. The presence of co-produced oxide phases in the co-hydration catalysts had negligible impact on reactivity.

Self-condensation of propanol over solid-base catalysts

2004 ◽  
Vol 275 (1-2) ◽  
pp. 103-110 ◽  
Author(s):  
A.S. Ndou ◽  
N.J. Coville
Keyword(s):  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts

Solid base catalysts obtained from hydrotalcite precursors, for Knoevenagel synthesis of cinamic acid and coumarin derivatives

2006 ◽  
Vol 308 ◽  
pp. 13-18 ◽  
Author(s):  
E. Angelescu ◽  
O.D. Pavel ◽  
R. Bîrjega ◽  
R. Zăvoianu ◽  
G. Costentin ◽  
...  
Keyword(s):  
Solid Base ◽  
Coumarin Derivatives ◽  
Solid Base Catalysts ◽  
Base Catalysts

scholarly journals Nitrogen-containing carbon nanotubes as solid base catalysts

2006 ◽  
pp. 4859 ◽  
Author(s):  
Stefan van Dommele ◽  
Krijn P. de Jong ◽  
Johannes H. Bitter
Keyword(s):  
Carbon Nanotubes ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts
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