Letters in Organic Chemistry - Volume 19, Issue 4, 2022

A facile and efficient method is reported for the one-pot transformation of aryl aldehydes to aryl nitriles using hydroxylamine hydrochloride and phosphorus tribromide in PEGDME 250. The conversion of various aryl aldehydes to the corresponding aryl nitriles occurred smoothly in high yields under the present reaction conditions.

Compound KAD22 (5-methoxy-1-methyl-2-{[4-(2-hydroxyphenyl)piperazin-1-yl]methyl}- 1H-indole) was designed as a potential dopamine D2 receptor agonist with antioxidant activity for possible treatment of Parkinson’s disease. The compound was obtained from 5-methoxy-1-methyl-1H-indole- 2-carbaldehyde and 2-(piperazin-1-yl)phenol. KAD22 showed no affinity to dopamine D2 receptor but it is a potent antioxidant. Experimental and computational structural studies (conformational analysis, HOMO and LUMO orbitals, electrostatic potential map, non-covalent interaction plot, spectral properties, ligand-receptor interactions) of KAD22 were performed to address its biological activity.

A simple, efficient and green protocol has been developed for the synthesis of polysubstituted dihydropyridines via one-pot, four-component reaction of aldehydes, arylamines, dialkyl acetylenedicarboxylate, and malononitrile. The reaction was proceeded at room temperature in the absence of catalyst in aqueous ethyl lactate under visible light irradiation. The main advantages of the present approach are mild reaction conditions, high yield, no column chromatography, clean reaction profile, environmentally friendly and sustainability from the economic point of view.

In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally friendly, and sustainable technology. Compared to other light sources in photochemical reaction, LEDs have advantages in terms of efficiency, power, compatibility, and environmentally friendly nature. This review highlights the most recent advances in LED-induced photochemical reactions. The effect of white and blue LEDs in reactions such as oxidation, reduction, cycloaddition, isomerization, and sensitization is discussed in detail. No other reviews have been published on the importance of white and blue LED sources in the photocatalysis of organic compounds. Considering all the facts, this review is highly significant and timely.

Aryl sulfonates were developed by ssing an energy-saving and eco-friendly approach, through ultrasound-assisted coupling reaction of readily sodium sulfinates with N-hydroxyphthalimide, under metal-free and mild conditions within 10 min at room temperature.

For the first time in the present study, the non-bonded interaction of the Coniine (C8H17N) with carbon monoxide (CO) was investigated by density functional theory (DFT/M062X/6-311+G*) in the gas phase and water solvent. The adsorption of the CO over C8H17N affected the electronic properties such as EHOMO, ELUMO, the energy gap between LUMO and HOMO, and global hardness. Furthermore, chemical shift tensors and the natural charge of the C8H17N and complex C8H17N/CO were determined and discussed. According to the natural bond orbital (NBO) results, the molecule C8H17N and CO acted as both electron donor and acceptor at the complex C8H17N/CO in the gas phase and water solvent. On the other hand, the charge transfer occurred between the bonding, antibonding or nonbonding orbitals in two molecules, C8H17N and CO. We have also investigated the charge distribution for the complex C8H17N/CO by molecular electrostatic potential (MEP) calculations using the M062X/6-311+G* level of theory. The electronic spectra of the C8H17N and complex C8H17N/CO were calculated by timedependent DFT (TD-DFT) for investigation of the maximum wavelength value of the C8H17N before and after the non-bonded interaction with the CO in the gas phase and water solvent. Therefore, C8H17N could be used as strong absorbers for air purification and reduce environmental pollution.

A new series of furan-2-carboxamide and 5-bromofuran-2-carboxamide derivatives have been prepared in good yields using simple procedures. Our strategy was to synthesize compounds containing functional groups that are known to exhibit significant bioactivity, such as amide (8-15), 2,4- dinitrophenylhydrazone (8a-15a), and thiosemicarbazone (8b-15b). These newly synthesized compounds have been characterized with the aid of a number of spectroscopic techniques, including 1HNMR, ¹³C-NMR, IR, and mass spectrometry, in addition two x-ray structures were measured. Antibacterial and antifungal activity of prepared compounds was investigated; antifungal results indicated that compound 8a is the most active, whereas compounds 15 and 9b showed moderate activity. Similarly, results of antibacterial testing revealed that most of the prepared compounds exhibit low activity, while compounds containing 2,4-dinitrophenylhydrazone moiety (9a-14a) are the most active towards E. Coli strain.

“Phase Transfer Catalyst” as additive was exposed to the Passerini three-component reactions and the influence of its accelerating effect on the reaction rate was studied concerning direct involvement of reactant molecules. For the rapid formation of diverse “α-acyloxycarboxamides” using passerini reaction, multicomponent reactions were employed using miscellaneous 2-(prop-2-ynyloxy) benzaldehyde with various aromatic acids and slightly non-polar fragment, i.e. 2-isocyano-2,3,3- trimethylbutane, and the representative molecule was characterized with DEPT-135 NMR technique.

A clean and efficient one-pot protocol for the synthesis of a series of new 2-hydroxy-3- ((3-aryl)(heteroarylamino)methyl)naphthalene-1,4-dione derivatives has been developed by the three-component reaction of 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes, and heterocyclic amines at 90 ^oC under solvent- and catalyst-free conditions. The procedure avoids the use of toxic solvents, tedious work-up, catalyst, and purification of the products by chromatographic methods. Simple operation, short reaction times, generation of the desired compounds in high to excellent yields, and an environmentally benign method are advantages of this protocol.