Bridged Alkyl Ionic Liquid‐Catalyzed Tandem Reaction for Synthesis of Spiro[4H‐pyran‐3,3′‐oxindoles] in Aqueous Ethanol Solution

Abstract

A new class of bridged alkyl ionic liquids has been successfully developed and they are shown to be efficient catalysts for the synthesis of a wide range of densely functionalized spiro[4Hpyran-3,3'-oxindole] derivatives. With only 1 mol% catalyst, all the reactions underwent smoothly in aqueous ethanol solution at ambient temperature and afforded the corresponding products in good to excellent yields within a short reaction time. This is a simple and green protocol with significant advantages such as the use of environmentally friendly solvent, mild conditions, easy work up, no chromatographic separation, and applicability for large-scale synthesis. The catalyst could be reused eight times at least. 2 3 4 5 6 7 8

[CMMIM][BF4] as a Sustainable Catalyst for Spirooxindoles Synthesis via One‐Pot Multicomponent Reaction: Insights into their Photophysical Properties and Theoretical Calculations

“…MCRs have demonstrated remarkable efficacy and success in generating a wide spectrum of structures, as well as facilitating the synthesis of various medically significant compounds. The domain of green or sustainable chemistry has captured significant attention in the 21 st century [3] . Recent investigations have focused on trailblazing environmentally sustainable procedures, employing inventive approaches.…”

“…Oxoindoles stand out as one of the most crucial classes of heterocyclic compounds. Compounds that contain the oxoindole moiety commonly demonstrate a diversity of biological activities [11] . Moreover, it was observed that spirooxindole derivatives possessing a spirocyclic stereocenter at the C‐3 position exhibit significantly enhanced biological activity [12] .…”

“…Compounds that contain the oxoindole moiety commonly demonstrate a diversity of biological activities. [11] Moreover, it was observed that spirooxindole derivatives possessing a spirocyclic stereocenter at the C-3 position exhibit significantly enhanced biological activity. [12] The spirocycles were widely integrated into the structural framework for several pharmaceuticals and natural products.…”

β-Cyclodextrin: a green supramolecular catalyst assisted eco-friendly one-pot three-component synthesis of biologically active substituted pyrrolidine-2-one

“…The water–ethanol reaction medium has been demonstrated to be an efficient system for the multi-component synthesis of biologically potent heterocyclic derivatives. 22–24…”

“…The waterethanol reaction medium has been demonstrated to be an efficient system for the multi-component synthesis of biologically potent heterocyclic derivatives. [22][23][24] Numerous examples of multi-component synthesis of pyrrolidinone derivatives using a variety of catalysts, such as the 34 and carbocatalyst graphene oxide, 35 have been reported in the literature. These working routes for synthesising pyrrolidinones include the condensation of aryl anilines, aromatic aldehydes and dialkylacetylenedicarboxylates using various metal catalysts, lanthanide catalysts, ionic liquids, nanoparticles, and acids.…”