Journal ArticleDOI
Heteropolyacids and large-pore zeolites as catalysts in acylation reactions using α,β-unsaturated organic acids as acylating agents
C. De Castro,J. Primo,A. Corma +2 more
TLDR
In this article, the influence of the catalyst on the selectivity for acylation and alkylation with crotonic acid has been studied, and it was shown that all the catalysts are more active for acylation than for alkylation.Abstract:
Pure phosphotungstic acid (H 3 PW 12 O 40 ), supported on SiO 2 and in the form of Cesium salts have been studied as acid catalysts for the acylation of toluene, p -xylene and m -xylene with crotonic acid. Since crotonic acid can either alkylate and/or acylate the alkylaromatic compounds, it was specifically selected to study the influence of the catalyst on the selectivity for these two competing reactions. Analysis of products obtained when acylating with an α , β -unsaturated acid show that all the catalysts are more active for acylation than for alkylation. Heteropolyacids were found to be more active than zeolites H-Y and Beta, even when the activity per acid site was considered. In the case of heteropolyacids, their activity is directly related to the number of accessible Bronsted acid sites.read more
Citations
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Journal ArticleDOI
Unique acid catalysis of heteropoly compounds(heteropolyoxometalates) in the solid state
TL;DR: In this paper, the properties of solid heteropoly catalysts are described, together with important principles required for the understanding and design of solid Heterpoly(oxometalates) catalysts.
Journal ArticleDOI
Use of solid catalysts in Friedel-Crafts acylation reactions.
Giovanni Sartori,Raimondo Maggi +1 more
Journal ArticleDOI
Catalysis by heteropoly compounds—recent developments
TL;DR: In this paper, the acid strength of typical heteropoly acid, H3PW12O40, was found to be higher than that of H2SO4 in liquid-state and H-ZSM-5 in solid-state.
Journal ArticleDOI
Friedel–Crafts acylation and related reactions catalysed by heteropoly acids
TL;DR: In this article, it is demonstrated that HPA-based solid acids are efficient and environmentally friendly catalysts for these reactions, usually superior in activity to the conventional acid catalysts such as H2SO4 or zeolites.
Journal ArticleDOI
Toward a rational control of solid acid catalysis for green synthesis and biomass conversion
Ken-ichi Shimizu,Atsushi Satsuma +1 more
TL;DR: In this article, a strategy for design of active catalysts for green chemical and biomass conversion processes is discussed and the important role of solid Lewis acids was suggested in acetylation of alcohols with acetic anhydride by cation-exchanged clay, Friedel-Crafts acylation and alkylation of aromatic compounds with metal salts of heteropolyacids.
References
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Journal ArticleDOI
Inorganic Solid Acids and Their Use in Acid-Catalyzed Hydrocarbon Reactions
TL;DR: In this article, the authors tried to describe perhaps the most important solid acids based on inorganic oxides, going from their preparation procedures and characterization, to their catalytic activity for a series of hydrocarbon reactions.
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Insoluble heteropoly compounds as highly active catalysts for liquid-phase reactions
TL;DR: In this paper, a liquid phase alkylation of m -xylene or trimethylbenzene with cyclohexene was studied using heteropoly compounds and other typical solid acids as the catalysts.
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Friedel-Crafts acylation of toluene and p-xylene with carboxylic acids catalyzed by zeolites
TL;DR: Acylation par des acides alcanoiques a longue chaine, en presence de zeolite Y du type faujasite as mentioned in this paper, in presence of zeolites
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Design of synthetic zeolites as catalysts in organic reactions
TL;DR: In this paper, anisole with phenylacetyl and phenylpropanoyl chlorides and 3-phenylpropionic acids was carried out in a batch reactor at 50-115°C over a series of zeolites Y at 21, 50 and 100% Na+ exchange, with a framework Si-to-Al ratio from 9 to 24.
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Acidic and catalytic properties of CsxH3−xPW12O40 heteropolyacid compounds
TL;DR: The catalytic properties of the more acidic catalysts are in the range Cs2/2.7 if considering a wide range of acid strengths evidenced by methanol conversion as discussed by the authors.