On the equivalence of acidic centers in H-beta zeolites tested by Fries rearrangement of phenyl acetate

The active site accessibility aspect of montmorillonite for ketone yield in ester rearrangement

“…[6][7][8][9] Many efforts have also been made to use ecocompatible, reusable, heterogeneous catalysts for acylation. Heteropoly acids, 1,6 acidic zeolites, 10,11 metal oxides, 12,13 cation-exchange and acid treated clays are the most studied heterogeneous catalysts. 9,14 The activity and selectivity of these catalysts have been investigated in direct acylation as well as rearrangement of several organic substrates such as aromatic ethers (anisole, thioanisole, veratrole, and 2-methoxy naphthalene), heterocyclic compounds (thiophene and benzofuran), phenolic compounds (phenol, p-cresol, naphthol and resorcinol) and aromatics [15][16][17][18][19][20] (toluene, biphenyl and naphthalene).…”

Substrate substitution effects in the Fries rearrangement of aryl esters over zeolite catalysts

“…A linear correlation was reported between the conversion of phenyl acetate and the degree of ion exchange of protonic sites with alkali metals. 11 In contrast, other studies found that the conversion was independent of the Si/ Al ratio of BEA zeolites. 8,26 The large number of products formed in the transformation of phenyl acetate over solid acids poses a major challenge for understanding the influence of distinct catalyst properties on the reaction scheme.…”

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Zeolites have long attracted interest for selective organic syntheses because of their characteristic acidity, potential for confinement effects, and good thermal stability. [20][21][22][23][24][25] Under appropriate conditions, they have been shown to present a viable alternative for conventional catalysts in the Fries rearrangement of simple substrates, [5][6][7][8][9][10][11] with most previous studies focusing on phenyl acetate. In general, liquid-phase tests result in improved selectivity over gas phase reactions, and are typically conducted at 373-463 K with batch operation preferred over continuous.…”

Heterogeneous catalytic reaction of microcrystalline cellulose in hydrothermal microwave-assisted decomposition: effect of modified zeolite Beta

“…Less incorporation of the cations K + and Zn +2 into the Beta framework were achieved when compared to the tin treatment. These cations show basic behaviour in catalysis 23 and were easily exchanged into the framework.…”