Task‐Specific Deep Eutectic Solvent for Selective Oxidation of Aromatic Methyl to Aldehyde

Abstract

Biodegradable and economically viable choline chloride-FeCl 2. H 2 O deep eutectic solvent (DES), was synthesized and successfully utilized as a catalyst and reaction medium for the selective oxidation of aromatic methyl groups to aldehydes. To demonstrate the synthetic potential of this protocol, the reaction was scaled up to the gram scale. The DES could be reused up to four times without considerable effect on the yield of the reaction. The key features of the protocol that qualify the process as green include the ambient reaction temperatures, easy isolation of the products, higher yields, recyclability of the catalyst, and reactions without the use of conventional organic solvents.

Ionic Liquids in Metal, Photo-, Electro-, and (Bio) Catalysis

“…The selective oxidation of aromatic methyl groups, as for example, in mesitylene to 3,5-di­methyl­benz­alde­hyde was performed in choline chloride/FeCl 2 by tert -butyl hydroperoxide (TBHP) (Scheme c) . This protocol allows easy product separation, allows catalyst recycling without the use of classical organic solvents, and is much more efficient than those reported using acetic acid.…”

An Efficient and Mild Method for the Alkylation of p-Cresol with tert-Butyl Alcohol

“…After 20 years of rapid development, deep eutectic solvents have been wildly applied in the extraction of biomass, absorption of acidic gas, organic synthesis, and other fields [17][18][19][20]. Particularly, different kinds of deep eutectic solvents have been used successfully as catalysts in esterification [21][22][23][24], oxidation [25][26][27], and alkylation reaction [28,29]. The wide application of deep eutectic solvents in chemical reactions is a green and efficient choice for catalytic reactions.…”