Silica-Coated Magnetic-Nanoparticle-Supported DABCO-Derived Acidic Ionic Liquid for the Efficient Synthesis of Bioactive 3,3-Di(indolyl)indolin-2-ones

Abstract

In this work, biologically significant 3,3-di(indolyl)indolin-2-ones have been synthesized using a silica-coated magnetic-nanoparticle-supported 1,4-diazabicyclo[2.2.2]octane (DABCO)-derived and acid-functionalized ionic liquid as the catalytic entity. The fabricated nanocomposite catalyzes the pseudo-three-component reaction of isatins and indoles explicitly via hydrogen-bonding interactions between substrates and the catalyst. The nanocatalytic system utilizes water as the green reaction medium to obtain a library of indolinones in good to excellent yields under mild reaction conditions. Besides, the catalyst could be easily recovered from the reaction mixture through simple external magnetic forces, which enables excellent recyclability of the catalyst for successive runs without appreciable loss in catalytic activity. Hence, the outcomes of the present methodology make the nanocatalyst a potential candidate for the development of green and sustainable chemical processes.

Friedel‐Crafts‐Type Reaction of (Het)Arenes with Aldehydes/Ketones under Acid‐Free Conditions using Neutral Ionic Liquid: A Convenient Routes to bis(Indolyl)methanes and Beyond

“…5′‐Chloro‐5, 5′′‐dimethoxy‐1H, 1′′H‐[3, 3′:3′, 3′′‐terindol]‐2′(1′H)‐one (5 f) : [34c] Following the general procedure, compound 5 f was obtained (3 h) in 84% yield as a white solid, M.P. 283–285 °C.…”

Chemistry of magnetic covalent organic frameworks (MagCOFs): from synthesis to separation applications

“…Relatively inexpensive and simple silica coating not only minimizes the aggregation but also provides many potential benefits such as chemical inertness, high binding strength with iron-oxide core, robustness, possibility for further functionalization, etc. [88][89][90][91][92][93][94][95] Further, amino groups were introduced on the surface of Fe 3 O 4 @SiO 2 to obtain amino-modified Fe 3 O 4 @SiO 2 @NH 2 . Afterwards, the monomers, p-phenylenediamine (PPD) and trimesoyl chloride (TMC) were added to obtain carboxylic acid rich MagCOFs (Fe 3 O 4 @COFs-COOH).…”

An Earth-abundant cobalt based photocatalyst: visible light induced direct (het)arene C–H arylation and CO2 capture

“…24,25 In this context, the interest of researchers is continually focused on the design and development of readily recoverable, reusable and economically feasible photocatalysts that allow promising prospects of deploying an abundant, renewable and clean source of solar energy or visible light for multifaceted catalytic applications. [24][25][26] In light of our on-going interest in developing heterogeneous photocatalysts and our group's expertise in the field of heterogeneous catalysis, [27][28][29][30][31] we became inspired to develop a viable and efficient noble metal free heterogeneous photo catalytic system that exhibits high stability and easy processability. Subsequentially, we devoted our attention toward harnessing the synergistic effects of facile recoverability of magnetic nanoparticles and photoactive properties of Earth abundant metal-based complexes that can ultimately serve as competent photocatalysts to address the limitations associated with conventional photoredox based materials.…”