Selective Sulfonylation of Arenes and Benzoylation of Alcohols Using Lithium Perchlorate as a Catalyst Under Neutral Conditions

Abstract

Sulfonylation of aromatics with p-toluenesulfonyl chloride and benzoylation of alcohols with benzoyl chloride using lithium perchlorate as a catalyst is described. The remarkable selectivity under neutral conditions is an attractive feature of this method

Chemoselective CaO‐Mediated Acylation of Alcohols and Amines in 2‐Methyltetrahydrofuran

“…Table 1, formation of ester 2 is clearly improved by the presence of an acid scavenger. Interestingly, CaO was the most effective compared to other alkaline-earth metal oxide such as MgO (entry 12) or to different bases such as K 2 CO 3 , KF-Celite, or triethylamine (entries [13][14][15]. The presence of 2.0 eq.…”

“…[6] Esterification reactions in the absence of activators are not fully understood and have limited substrate scope (aromatic acid chlorides or compounds with a-acidic hydrogens are not used); this may be attributed to a considerable excess of the required acyl donor. [7] These limitations stimulated efforts to develop activators for improving the reactivity, among the most common are Brønsted acids (e.g., HCl, [8] p-TsOH [9] ) and Lewis acids (e.g., CeCl 3 , [10] MgBr 2 , [11] ZrCl 4 , [12] Sc(OTf) 3 , [13] LiClO 4 , [14] Mg(ClO 4 ) 2 [15] ). These acids cannot be used in the presence of acid-sensitive substrates, thus reducing their real usefulness.…”

The Acylation of Heteroatoms

“…These reactions often proceed only slowly, and conditions suitable for most primary or secondary alcohols will fail with tertiary alcohols [46][47][48]. These reactions often proceed only slowly, and conditions suitable for most primary or secondary alcohols will fail with tertiary alcohols [46][47][48].…”

Sulfonylation reactions of aromatics using FeCl3-based ionic liquids

“…Their immense utility in medicinal chemistry has resulted in development of their synthesis in various academic laboratories and process development groups. Among Friedel-Crafts (FC) type reactions, sulfonylation possess is an important problem in catalysis [5][6][7][8][9][10][11][12].…”