Selectivity engineering of 4-phenoxyacetophenone by acylation of diphenyl ether with ion exchange resins: modeling of catalyst deactivation and remedies

Synthesis of carvacrol by Friedel–Crafts alkylation of o‐cresol with isopropanol using superacidic catalyst UDCaT‐5

“…7 Thus, it is apparent that there is still some scope to develop better catalysts which would catalyze the isopropylation of ocresol with excellent conversion and selectivity at comparatively low temperatures, with ease of preparation and having good reusability and stability in the presence of water. The activity and selectivities of different solid acid catalysts such as zeolites, 8,9 modified clays and heteropoly acids, 7,10 sulfated zirconia, 11 -14 ion exchange resins 15,16 and UDCaT series of catalysts 17 -19 have been successfully evaluated in our laboratory for developing green processes. The use of mesoporous materials as catalysts has been growing over the past decade.…”

Acylation of salicylamide to 5-acetylsalicylamide using ionic liquids as dual catalyst and solvent

“…It is reported that ion exchange resins [5], zeolites [6], Nafion [7], and heteropoly acids [8] can be used as alternatives to conventional anhydrous aluminum trichloride catalyst for acylation reactions. But these catalysts encounter with the disadvantages, such as low activity, low selectivity, and rapid deactivation.…”

Insight into Friedel-Crafts acylation of 1,4-dimethoxybenzene to 2,5-dimethoxyacetophenone catalysed by solid acids—mechanism, kinetics and remedies for deactivation

“…Zeolite HY and H␤ in chlorobenzene have been used for acylation of aromatic ethers at higher temperatures but still deactivation of the catalyst occurs rapidly due to the saturation of the active sites by the products acetic acid and/or the acylated product [3][4][5][6][7]. As an alternative to zeolites, several acylations of substituted benzenes were investigated with a variety of catalysts in our laboratory, including sulfated zirconia, UDCaT-1, UDCaT-5, dodecatungostophosphoric acid (DTP) supported on K10 clay (20% w/w DTP/K10), dodecatungostophosphoric acid (DTP), partially substituted with Cs (Cs 2.5 H 0.5 P 12 W 40 ) and supported on K10 clay (20% w/w Cs-DTP/K10) and ion exchange resins [8][9][10][11][12][13][14][15][16][17][18][19][20]. UDCaT-1 and UDCaT-5 are mesoporous solid superacids developed by us.…”

“…In the case of acylation of ethers, 20% DTP/hexagonal mesoporous silica (HMS) and cation exchange resins were more active but deactivation was still a problem [18]. There is a dearth of systematic studies on acylation of aromatic ethers which deactivate solid acids in liquid phase reactions.…”