An efficient, room temperature, oxygen radical anion (O₂^•−) mediated, one-pot, and multicomponent synthesis of spirooxindoles

Abstract

The present report highlights an efficient use of oxygen radical anion to promote a room temperature multi-component synthesis of spirooxindoles (4a–4l) under mild reaction conditions. The potassium superoxide (KO2) and tetraethylammonium bromide (TEAB) combination generate the oxygen radical anion in situ to promote this transformation. This method offers a sustainable and direct access to the biologically important spirooxindole derivatives in good to excellent yields.

Engaging Isatins in Multicomponent Reactions (MCRs) – Easy Access to Structural Diversity

“…), a phase transfer catalyst, act as the best combination to access the desired spirooxindoles in good yields at room temperature, through the reaction of isatins, dimedone/barbituric acid/Meldrum's acid, and malononitrile/ethyl cyanoacetate (Scheme 69B). Despite good scope, short reaction time and an innovative protocol, the use of toxic DMF as solvent and chromatographic purification work‐up turns this superoxide ion‐based methodology less advantageous when compared to other procedures [138] . In contrast, Hussen et al .…”

Greener Synthesis, Molecular Docking and Anticancer Studies of A New Series of 6‐Hydroxy‐5‐(3‐(3‐hydroxy‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)‐2‐oxoindolin‐3‐yl) pyrimidine‐2,4(1H,3H)‐diones

“…The structures of some important and biologically active compounds containing spirocyclic rings are shown in Figure. 1 [6–26] …”

Eco-Friendly and Facile Synthesis of Substituted Imidazoles via Nano Zirconia Catalyzed One-Pot Multicomponent Reaction of Isatin Derivatives with Ammonium Acetate and Substituted Aromatic Aldehydes under Solvent Free Conditions

“…In view of the above and as a part of our research group to synthesize the biologically active compounds [68][69][70][71][72], it was thought worthwhile to synthesize some novel imidazoles fused with indole nucleus of biocidal interest because the combination of two or more different heterocyclic compounds in a single molecule frequently increases the biocidal profile amazingly. With the aim of getting targeted products, i.e., substituted imidazole a greener "NOSE" (nanoparticles-catalyzed organic synthesis enhancement) approach has been designed under solvent-free conditions.…”