Synthesis and anti-inflammatory activity of 2-oxo-2H-chromenyl and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates

Synthesis and in Silico Study of Novel Benzisoxazole-Chromene Derivatives as Potent Inhibitors of Acetylcholinesterase: Metal-Free Site-Selective C-N Bond Formation via Aza-Michael Reaction

An efficient metal-free approach for site selective C-N coupling reaction of benzo[d]isoxazole and 2H-chromene derivatives has been designed and developed against AchE. This nitrogen containing organo-base promoted methodology, which is both practical and environmentally friendly, provides an easy and suitable pathway for synthesizing Benzisoxazole-Chromene (BC) possessing poly heteroaryl moieties. The synthesized BC derivatives 4 a-n was docked into the active sites of AChE to obtain more perception into the binding modes of the compounds. Out of them, compound 4 a and 4 l displayed potent activity and high selectivity against the AChE inhibition. Final docking results indicates that compound 4 l showed the lowest binding energy of -11.2260 kcal/mol with AChE. The synthesized BC analogs would be potential candidates for promoting suitable studies in medicinal chemistry research.

2H-Pyrano[3,2-c]chromene-2,5(6H)-diones: Synthesis, Characterization, Photophysical and Redox Studies for Potential Optoelectronic Applications

Herein, we report the preparation of 2H-pyrano[3,2-c]chromene-2,5(6H)-diones 3a-x by reacting 4-hydroxycoumarins 1a-b with Baylis-Hillman adducts 2a-w having electron releasing or electron withdrawing groups on benzyl ring of the pyranochromene moiety and study of their photophysical properties. The study of optical and electrochemical properties of the prepared compounds reveals that the electron releasing and electron withdrawing groups has not much impact on ground and excited state electronic behavior on pyranochromene moiety. The density functional theory suggests the highest occupied molecular orbital and lowest unoccupied molecular orbitals spread on coumarin moiety of pyranochromene unit. Further, these compounds are thermally stable (up to 200 °C) and lead to blue or green emission that should facilitate the development of organic light emitting diodes (OLEDs).

Cobalt-catalyzed modular assembling toward multi-functionalized furan derivatives

A cobalt-catalyzed modular [3+2] assembling of unsaturated hydrocarbons and β-dicarbonyls is reported. This protocol features mild reaction conditions and a broad substrate scope, providing facile entries toward diverse multi-functionalized dihydrofuran...

Lambert Salt-Initiated Development of Friedel-Crafts Reaction on Isatin to Access Distinct Derivatives of Oxindoles

Herein, a mild metal-free and efficacious route for the synthesis of biologically important 3-aryl oxindole derivatives is described. Using Lambert salt-initiated hydroarylation of isatin, a diverse array of monoarylated products, symmetrical/unsymmetrical double-arylated products, and deoxygenated hydroarylated products could be synthesized from the single starting substrate in good to excellent yields. A preliminary mechanistic study revealed that the reaction proceeds via a monoarylated product followed by a nucleophilic attack by another electron-rich arene nucleophile under mild conditions. The potential of newly synthesized symmetric/unsymmetric 3,3-disubstituted oxindole, 3-substituted 3-hydroxy oxindoles, 3,3-di(indolyl)indolin-2-ones, and α-aryl oxindoles as valuable building blocks is further illustrated.

Tandem Michael Addition-Cyclization of Nitroalkenes with 1,3-Dicarbonyl Compounds Accompanied by Removal of Nitro Group

A tandem Michael addition-cyclization of nitroalkenes with 1,3-dicarbonyl compounds was developed using phase transfer catalyst (PTC), allowing for the synthesis of polysubstituted-[4,5]-dihydrofuran in high yields. A wide range of substrates were demonstrated by this one-step process. Meanwhile, nitro group was substituted to form corresponding nitrite ion detected in the aqueous phase providing a reasonable pathway for denitrating poisonous and explosive nitro-containing compounds. The proposed mechanism was also supported by our DFT calculations.

4-Chloro-3-formylcoumarin as a multifaceted building block for the development of various bio-active substituted and fused coumarin heterocycles: a brief review

This review presents the diverse synthesis of 3,4-substituted coumarins and 5-, 6- and 7-membered ring fused coumarins using 4-chloro-3-formylcoumarin as the precursor via classical reactions including metal-catalyzed and green reaction protocols.