12-Tungstophosphoric Acid Immobilized on γ-Fe2O3@SiO2 Core–Shell Nanoparticles: An Effective Solid Acid Catalyst for the Synthesis of Indole Derivatives in Water

2012 ◽  
Vol 41 (4) ◽  
pp. 438-440 ◽  
Author(s):  
Ezzat Rafiee ◽  
Sara Eavani ◽  
Bizhan Malaekeh-Nikouei
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Tungstophosphoric Acid ◽  
Core Shell ◽  
Indole Derivatives ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Preparation of Core-Shell Silica - 12-Tungstophosphoricacid Nanoparticles for Acylation of Aromatics

2013 ◽  
Vol 706-708 ◽  
pp. 219-223
Author(s):  
Hsiu Ling Hsu ◽  
Rosilda Selvin ◽  
L. Selva Roselin
Keyword(s):  
Liquid Phase ◽  
High Activity ◽  
Solid Acid ◽  
Coke Formation ◽  
Solid Acid Catalysts ◽  
Core Shell ◽  
Acid Catalysts ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
Enhanced Selectivity

A variety of solid acid catalysts especially 12-Tungstophosphoricacid (DTP) supported on silica has been reported for the acylation of anisole, veratrole and toluene. However, the activity of this catalyst is susceptible to coke formation or poor activity. This paper reports the novelties of steam treated SiO2-DTP core-shell nanoparticles, which exhibits tremendous stability, high activity and enhanced selectivity in the liquid-phase acylation of anisole, veratrole and toluene as compared to conventional DTP supported on silica.

Application of Fe3O4@SiO2/(CH2)3-[imidazolium-SO3H]Cl as a robust, magnetically recoverable solid acid catalyst for the facile preparation of arylbispyranylmethanes

2017 ◽  
Vol 95 (12) ◽  
pp. 1248-1252 ◽  
Author(s):  
Mohammad Ali Zolfigol ◽  
Mahdiyeh Navazeni ◽  
Meysam Yarie ◽  
Roya Ayazi-Nasrabadi
Keyword(s):  
Effective Potential ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Core Shell ◽  
Synthetic Procedure ◽  
Three Component Reaction ◽  
Facile Preparation ◽  
Green Conditions

In this study, Fe3O4@SiO2/(CH2)3-[imidazolium-SO3H]Cl shows robust promoting capability in the synthesis of arylbispyranylmethane derivatives under mild and green conditions. Arylbispyranylmethanes were synthesized via efficient three-component reaction of various aromatic aldehydes with 4-hydroxy-6-methyl-2H-pyran-2-one. The nanomagnetic core-shell catalyst presented effective potential of at least eight times recycling applicability in the described synthetic procedure.

scholarly journals Synthesis of Medicinally Important Indole Derivatives: A Review

2021 ◽  
Vol 15 (1) ◽  
pp. 1-16
Author(s):  
Deeptanu Sarkar ◽  
Andleeb Amin ◽  
Tanzeela Qadir ◽  
Praveen K. Sharma
Keyword(s):  
Ionic Liquids ◽  
Microwave Irradiation ◽  
Functional Group ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Indole Derivatives ◽  
Site Specific ◽  
Bioactive Natural Products ◽  
Solvent Free Conditions

Indoles constitute a widely occurring functional group in nature and are present in an extensive number of bioactive natural products and medicinally important compounds. As a result, exponential increases in the development of novel methods for the formation of indole core along with site-specific indoles have been established. Conventional methods for the synthesis of indoles are getting replaced with green methods involving ionic liquids, water as a solvent, solid acid catalyst, microwave irradiation and the use of nanoparticles under solvent-free conditions. In addition, there are immense applications of the substituted indoles in diverse fields.

A green solid acid catalyst 12-tungstophosphoric acid H3[PW12O40] supported on g-C3N4 for synthesis of quinoxalines

2020 ◽  
Vol 46 (9) ◽  
pp. 4193-4209
Author(s):  
Murugan Kumaresan ◽  
Vadivel Saravanan ◽  
Ponnusamy Sami ◽  
Meenakshisundaram Swaminathan
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Tungstophosphoric Acid

Tungstophosphoric Acid Entrapped on Mesoporous Silica via Sol Gel Technique

2006 ◽  
Vol 11-12 ◽  
pp. 69-72
Author(s):  
Joon Ching Juan ◽  
Yarmo Mohd Ambar ◽  
Jing Chang Zhang
Keyword(s):  
Mesoporous Silica ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Chemical Properties ◽  
Acid Catalyst ◽  
Tungstophosphoric Acid ◽  
Esterification Reaction ◽  
Heterogeneous Acid Catalyst ◽  
Gel Technique

The heterogeneous 12-tungstophosphoric acid (HPW) catalyst is becoming important in industrial processes for example in esterification reaction. A novel solid acid catalyst of HPW entrapped on mesoporous silica was synthesized by sol gel technique. Neutral template dodecylamine was introduced to obtain mesopores structure catalyst. The physical and chemical properties of the catalyst were characterized by XRD, nitrogen sorption and FTIR. In conclusion, this new type of mesoporous solid acid catalyst is a very promising heterogeneous acid catalyst for esterification reaction involving bulky molecules such as fatty acid.

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