Heterogeneous catalysis for the acetylation of benzo crown ethers

An Environmentally Friendly Route for the Synthesis of Benzofurane Derivatives using Selective Ring Acylation of Resorcinol

“…Accordingly the mechanism suggested for the reaction of isobutyryl chloride on resorcinol involves the formation of an acyl cation by oxidation of the chloride as proposed earlier [16,20]. This mechanism agrees with the results reported for acylations and alkylations catalysed by indium, gallium and thallium oxides or chlorides supported on alumina and zeolites [21][22][23].…”

“…The elimination of the solvent changes the kinetics of the reaction and may require a change of catalyst. For instance Sn 2+ -K10, which was reported as good catalyst for the acylation of crown ethers by acetyl chloride [16], was a poor one for the reaction of resorcinol with phenylacetyl chloride [1]. Therefore the choice of the cation is controlled by the reactivity of the substrates.…”

Acid catalyzes the synthesis of aromatic gem-dihalides from their corresponding aromatic aldehydes

“…Increasing the calcination temperature decreased sulfur content and surface area and increased the crystal size and crystallization of ZrO 2 into the tetragonal phase, in agreement with previous reports [41][42][43]. In addition, it can be seen from Table 4 that benzal chloride yield reached the maximum after activation of the catalyst at 550 • C. It was previously demonstrated that the ratio of Bronsted to Lewis sites at the surface of sulfated zirconia diminishes at high calcination temperatures [44]. However, a combination of a relatively high loading of sulfate species, high surface area and the nature of surface acidity (after 50% crystallization of zirconia phase at a calcination temperature of 823 K) are important.…”

Review of SO 2− 4 /M x O y solid superacid catalysts

“…Some researchers reported to use SO 2 -4 =M x O y catalysts for the alkylation of acylation and Friedel-Crafts acylation, such as the acetylation of benzo-15-crown-5 [89], benzoylation [90], acetylation [91], and aromatic ethers [11].…”