This review illustrates various roles played by ionic liquids in organic transformations, such as solvents, additives, promoters, electrolytes and catalysts for the synthesis and functionalization of heterocycles and carbocycles through C–H activation reactions. Ionic liquids offer several advantages such as high stability, intrinsic conductivity, non-volatility, and recyclability, making them appealing alternatives to traditional organic solvents in sustainable organic synthesis. Their unique properties enhance reaction performance, as seen with recyclable [EMIM]BF₄ in quinazolinone synthesis and [TMG][CF₃COO] in amide production, direct diarylation of 6,7-benzindoles, regioselective reactions with aryl iodides, catalytic cyclopropanation with tetrabutylammonium acetate (TBAA), and propargylamine synthesis via A³ coupling reactions. The use of functionalized ionic liquids like [Bmim]PF₆ with phosphine-ligated Pd(II) enhances product isolation, facilitates reactions under mild conditions, and promotes reusability, contributing to environmentally friendly pathways. Thus, this review highlights various ionic liquids used in different reactions, emphasizing their benefits in improving yields, solubility, and product separation in catalytic processes.

The p-toluene sulfonic acid (p-TSA) catalyzed cascade ring closing transformation has been executed for the preparation of novel spiroquinazolinone compounds 4 and 5 by the reaction between anthranilamide and cyclohexanone followed by subsequent acylation. These molecules were then examined against the inhibitory activity of Acetylcholineterase (AchE). The tested compounds revealed moderate anti-AChE activity of IC₅₀ values ranging from 46.675 to 14.256 µM). The described results lead toward the development of compounds 4b and 5c having promising anti-AChE activities with IC₅₀ values at the micromolar level. The docking study suggests that these hybrid spiroquinazolinone scaffold might facilitate the further development of investigated compounds as anti-Alzheimer agents.

This review emphasizes on the recent advances on the synthesis of triarylmethanes using regio- and stereoselective approaches, aiming to engage readers in organic synthesis.