Acylation of B15C5 crown ether by acetic anhydride in the absence of solvent, on sulfated zirconias prepared in different conditions

Comparative Study of Regioselective Synthesis of β-Aminoalcohols under Solventless Conditions Catalyzed by Sulfated Zirconia and SZ/MCM-41

“…In this context, some acid models have been proposed to explain the acid features of SZ [4]. Sulfated zirconia acidity has proven to be useful in organic transformations such as n-butane isomerization, [5] Friedel-Craft acylations, [6,7] fine chemical organic transformations, [8] alcohol dehydrations, [9] and polymerizations [10]. Typically, the surface area of solid catalysts is an important factor that directly influences their catalytic performance.…”

Sulfated Zirconia-Catalyzed Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones (DHPMs) Under Solventless Conditions: Competitive Multicomponent Biginelli vs. Hantzsch Reactions

“…Aside the fact that they have excellent activity and selectivity, even on industrial scales, and in most cases these substances can be recovered from reaction mixtures and reused with good results [4], these solid acids are important from an environmental point of view because they produce less hazardous by-products. In this context, solid sulfated zirconia [5] have been used, due to their acidic and shape-selective nature, for performing the synthesis of heterocycles [6,7], acylation of aromatics ketones [8] and stereocontrolled glycosidations [9], synthesis of aromatic gem-dihalides [10], acylation of crown ethers [11], and chemoselective synthesis of acylals from aromatic aldehydes and their deprotections [12]. It is also known that in many cases organic reactions under solvent free conditions occur more efficiently and more selectively than do their solutions counterparts [13].…”

Oxo‐Anion Modified Oxides

“…Correlations of the reaction rate to the total number of acid sites as measured by ammonia adsorption are not always convincing, e.g. a poor correlation was obtained for an acylation reaction [44]; good correlations were observed for 2-propanol dehydration and cumene dealkylation [45]. On the other hand, the n-butane isomerization rate was found to be proportional to the number of Brønsted acid sites as determined by pyridine adsorption [46].…”

“…Hydrolysis of alkoxides, which are soluble in e.g. ethanol, 1-propanol, isopropanol or cyclohexane [44], can be initiated by water [94,95], acids [90] or bases [33]. For other oxides, e.g.…”