PEG-mediated one-pot multicomponent reactions for the efficient synthesis of functionalized dihydropyridines and their functional group dependent DNA cleavage activity

Genotoxic and genoprotective effects of 1,4-dihydropyridine derivatives: a brief review

This review summarises current knowledge about the genotoxic and genoprotective effects of 1,4-dihydropyridines (DHP) with the main focus on the water-soluble 1,4-DHPs. Most of these water-soluble compounds manifest very low calcium channel blocking activity, which is considered "unusual" for 1,4-DHPs. Glutapyrone, diludine, and AV-153 decrease spontaneous mutagenesis and frequency of mutations induced by chemical mutagens. AV-153, glutapyrone, and carbatones protect DNA against the damage produced by hydrogen peroxide, radiation, and peroxynitrite. The ability of these molecules to bind to the DNA may not be the only mechanism of DNA protection, as other mechanisms such as radical scavenging or binding to other genotoxic compounds may take place and enhance DNA repair. These uncertainties and reports of high 1,4-DHP concentrations damaging the DNA call for further in vitro and in vivo preclinical research, pharmacokinetic in particular, as it can help pinpoint the exact mechanism(s) of the genotoxic and/or genoprotective action of 1,4-DHPs.

Greener Synthesis of Nitrogen-Containing Heterocycles in Water, PEG, and Bio-Based Solvents

The solvents used in chemistry are a fundamental element of the environmental performance of processes in corporate and academic laboratories. Their influence on costs, health safety, and nature cannot be neglected. Quantitatively, solvents are the most abundant constituents of chemical transformations; therefore, acting on solvents and replacing standard solvents with safer products can have a great ecological impact. However, not all green solvents are suitable for the wide scope of organic chemistry reactions. A second point to consider is that 50% of pharmaceutical drugs are nitrogen heterocycles compounds. It therefore appeared important to provide an overview of the more ecological methodologies for synthesizing this class of compounds. In this review, all publications since 2000 that describe green reactions leading to the formation of nitrogen heterocycles using safe solvents were considered. We chose water, PEG, and bio-based solvents for their negligible toxicity. The synthesis of five-, six-, and seven-membered aromatic nitrogen heterocycles using green reactions reported in the literature to date is described.

Synthesis of Unsymmetrical 1,4-dihydropyridines from Dialkyl Acetylenedicarboxylates, Amines and Arylidenemalononitriles Promoted by Potassium Carbonate

The one-pot, three-component reaction of dialkyl acetylenedicarboxylates, arylamines and arylidenemalononitriles in the presence of potassium carbonate in acetonitrile at 50 °C afforded 11 6-amino-5-cyano-1,4-dihydropyridine-2,3-dicarboxylates, nine of which are novel. These conditions offer simplified operation, easy purification and good yields. Also, this method avoids the use of expensive catalysts, toxic solvents and chromatographic separation.

Ultrasound mediated, green innovation for the synthesis of polysubstituted 1,4-dihydropyridines

An atom efficient protocol via a one-pot four-component cyclocondensation reaction catalyzed by copper(i) iodide in aqueous medium under ultrasonic irradiation has been developed for the synthesis of novel polysubstituted 1,4-dihydropyridines.

Catalyst-free, one-pot, four-component green synthesis of functionalized 1-(2-fluorophenyl)-1,4-dihydropyridines under ultrasound irradiation

A catalyst-free synthesis protocol for functionalized 1,4-dihydropyridines under ultrasonic irradiation in aqueous ethanol is reported with excellent yields. Eleven new compounds are synthesized using dimethylacetylenedicarboxylate, 2-fluoroaniline, malononitrile and various substituted aldehydes.

Ultrasound assisted multicomponent reactions: a green method for the synthesis of highly functionalized selenopyridines using reusable polyethylene glycol as reaction medium

A simple and benign one-pot protocol for the synthesis of 2-amino selenopyrindine derivatives 4 has been developed using ultrasound assisted multicomponent reactions of aldehydes, malononitrile and benzeneselenol in PEG-400.

Manganese ferrite nanoparticle catalyzed tandem and green synthesis of spirooxindoles

PEG-400 as a nontoxic, green and reusable solvent was used for the synthesis of novel spiro-furo-pyridine-indoline-carbonitriles in the presence of a magnetically recoverable nanocatalyst.

Multicomponent reactions for facile access to coumarin-fused dihydroquinolines and quinolines: synthesis and photophysical studies

A three-component reaction of 4-hydroxycoumarin, aldehydes and aromatic amines in the presence of catalytic amounts of Bi(OTf)₃ is reported. Photophysical studies of these molecules showed that coumarin-fused dihydroquinolines exhibit significant quantum yields.

L-proline catalyzed multicomponent reactions: facile access to 2H-benzo[g]pyrazolo[3,4-b]quinoline-5,10(4H,11H)-dione derivatives

Three component reaction of 2-hydroxy 1,4-naphthoquinones, aldehydes, and aminopyrazoles in the presence of a catalytic amount ofl-proline has been described for the synthesis of a series of 2H-benzo[g]pyrazolo[3,4-b]quinoline-5,10(4H,11H)-dione derivatives.

“On-water” synthesis of novel trisubstituted 1,3-thiazolesviamicrowave-assisted catalyst-free domino reactions

A clean, efficient and catalyst-free multicomponent domino reaction of arylglyoxals, cyclic 1,3-dicarbonyls and thioamides in aqueous media under microwave conditions is reported.