Tunable Aryl Imidazolium Recyclable Ionic Liquid with Dual Brønsted–Lewis Acid as Green Catalyst for Friedel–Crafts Acylation and Thioesterification

Abstract

Unique tunable aryl imidazolium ionic liquids successfully catalyzed Friedel–Crafts acylation and thioesterification in sealed tubes. These reactions can form a C−C bond and a C−S bond with high atom economy. Ionic liquids exhibited high activity and catalyzed essential reactions with good to excellent yields while retaining their catalytic activities for recycling.

Enabling Sustainable Chemistry with Ionic Liquids and Deep Eutectic Solvents: A Fad or the Future?

“…ILs catalyze other chemical reactions such as Friedel–Craft alkylation and acylation or shift the reaction equilibrium to favor the product (Figure 6). [113, 125–131] In some of these reactions, the IL catalyst provides similar activity, selectivity, and conversion as the traditional catalyst, besides being less toxic and less volatile (Figure 6). [125, 130] A triethylammonium chloroaluminate IL catalyzes the acylation of isobutylbenzene, a precursor to Ibuprofen, with the catalytic activity reaching 99 % and selectivity approaching 96 %, similar to those obtained with conventional catalysts that are corrosive [130] .…”

Mechanism of Friedel–Crafts Acylation Using Metal Triflate in Deep Eutectic Solvents: An Experimental and Computational Study

“…Friedel–Crafts acylation reaction is one of the important reactions of synthetic aromatic ketones. , The common acylation reaction employs acyl chlorides, acid anhydrides, or carboxylic acids as acylating reagents in the presence of traditional catalysts including Lewis acids − (anhydrous ZnCl 2 , A1Cl 3 , FeCl 3 ) or Brønsted acids − (concentrated sulfuric acid, hydrochloric acid), nanoparticles, − ionic liquids, − metal triflates, , mesoporous zeolite, nitrogen-doped carbon, , metal oxides, heteropoly acids, , and solid superacids . Besides, several effective methods were applied to the Friedel–Crafts acylation reaction, including flow chemistry, ultrasound activation, and microwave irradiation …”

Autocatalytic Friedel‐Crafts Acylation of Arenes without Additional Catalyst and Additive

“…For example, Kroutil and co‐workers have reported biocatalytic Friedel‐Crafts acylation by acyltransferase [11] . Luo, Ho and co‐workers have used aryl imidazolium recyclable ionic liquid as the catalyst to enable this kind of reactions [12] . Aube and co‐workers have described another interesting method where hexafluoro‐2‐propanol (HFIP) was used to activate the C−Cl bond of acyl chlorides through a strong hydrogen‐bonding interaction between the Cl atom and HFIP to give the acylation products [13] .…”