Synthesis of novel pyrano[3,2-c]quinoline-2,5-diones using an acidic ionic liquid catalyst

Tandem Protocol for the Synthesis of Pyrano[3,2-c]quinolone Derivatives Using Taurine as a Green Bio-Organic Catalyst in Aqueous Medium

A series of pyrano[3,2-c]quinolone derivatives has been synthesized in the presence of taurine (2-aminoethanesulfonic acid) as a green bio-organic catalyst and water as the solvent. The target compounds were synthesized through the three-component reaction between aldehydes, malononitrile/ethylcyanoacetate, and 4-hydroxy-1-methyl-2(1H)-quinolone. The advantages of this protocol are excellent yields of products, short reaction times, cost efficiency, atom economy, and a simple work-up procedure with no need for extra purification techniques. Moreover, the catalyst can be easily recovered and reused for up to three cycles without losing any significant activity.

A new procedure for the preparation of 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazolinone derivatives catalyzed by SCMNPs@CA-EA-SO3H under solvent-free conditions

Abstract:

Catalyzed with SCMNPs@CA-EA-SO3H, as a green and heterogeneous solid acid catalyst, 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazolinone derivatives were obtained in high-to-excellent yields and in short reaction times via the one-pot multi-component condensation of ethyl acetoacetate or dimedone, urea, and aldehyde compounds under solvent-free conditions. More importantly, the green catalytic system could be easily collected from the reaction solution utilizing an external magnet and reused for five runs with a negligible decrease in yields and reaction rate.

Mo@GAA-Fe3O4 MNPs: a highly efficient and environmentally friendly heterogeneous magnetic nanocatalyst for the synthesis of polyhydroquinoline derivatives

Polyhydroquinolines were efficiently obtained from a sequential four-component reaction between dimedone or 1,3-cyclohexandione, ethyl acetoacetate, or methyl acetoacetate as a β-ketoester, aldehydes, and ammonium acetate, under the catalysis of Mo@GAA-Fe3O4 MNPs as a green, effective, recyclable, and environmentally friendly nanocatalyst. Due to its magnetic nature the prepared catalyst can be easily separated from the reaction mixture by an external magnet and reused several times without significant changes in catalytic activity and reaction efficiency. The catalyst was characterized using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

An efficient and green synthesis of ferrocenyl-quinoline conjugates via a TsOH-catalyzed three-component reaction in water

An efficient and green synthesis of 4-ferrocenylquinoline derivatives through a TsOH-catalyzed three-component reaction of aromatic aldehydes, amines and ferrocenylacetylene in water has been successfully developed. This strategy is a powerful method for the construction of diverse ferrocenyl-quinoline conjugates from simple available starting materials as it minimized the use of metal catalyst and organic solvent in the reaction process. The conjugates feature unique structures and excellent electronic properties. Moreover, a plausible mechanism for this TsOH-catalyzed three-component reaction was proposed and assessed.

We have successfully developed a green method for facile and efficient synthesis of ferrocenyl-quinoline conjugates from available starting materials via a TsOH-mediated three-component reaction in water.

Efficient one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by a new heterogeneous catalyst based on Co-functionalized Na+-montmorillonite

A facile and efficient solvent-free protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones by using Co@imine-Na⁺-MMT as a new, environmentally friendly and reusable heterogeneous catalyst is reported.

(CTA)3[SiW12]–Li+–MMT: a novel, efficient and simple nanocatalyst for facile and one-pot access to diverse and densely functionalized 2-amino-4H-chromene derivatives via an eco-friendly multicomponent reaction in water

A simple, facile and highly efficient one-pot synthesis of a pharmaceutically interesting diverse kind of functionalized 2-amino-4H-chromene is reported.

The deep eutectic melt of sorbitol and metformin hydrochloride: synthesis of 3-substituted 2-aminonaphtho[2,3-b]furan-4,9-diones and their photophysical properties

The low-melting deep-eutectic mixture of sorbitol and metformin HCl was successfully employed as a recyclable solvent for promoting the synthesis of benzofuroquinone dyes.

Use of a novel multicomponent reaction under high pressure for the efficient construction of a new pyridazino[5,4,3-de][1,6]naphthyridine tricyclic system

A novel multicomponent reaction between the 2-phenylhydrazono derivative1a, malononitrile and aromatic aldehydes or acetone, carried out under high pressure, was found to generate pyridazino[5,4,3-de][1,6]naphthyridine derivatives9a–hand22.

Synthesis of functionalized chromones through sequential reactions in aqueous media

An efficient sequential four-component reaction of chromone carbaldehydes, Meldrum's acid, 4-hydroxyl coumarin or 6-methyl-4-hydroxyl-pyrone and primary alcohols is reported which leads to 5a-i in aqueous media. Replacing the primary alcohol with isopropyl alcohol and tert-butyl alcohol results in different products 10 and 11. The environmentally friendly features, good to high yields and easy work-up are advantages of this approach.

Brønsted acidic ionic liquid catalyzed tandem reaction of 4-hydroxy-1-methyl-2-quinolone with chalcone: regioselective synthesis of pyrano[3,2-c]quinolin-2-ones

Task specific ionic liquid [1-methyl-3-(4-sulfobutyl)imidazolium-4-methylbenzenesulfonate] is an excellent catalyst for the synthesis of pyrano[3,2-c]quinolin-2-one derivatives.