Current Organic Chemistry - Volume 27, Issue 6, 2023

The design and synthesis of an efficient Ni-MgO solid solution catalyst with specific morphology for the hydrogenation of nitroarenes is highly required. In this work, a banana- like Ni-MgO solid solution incorporation of carbon catalyst (termed as Ni/MgO-C) has been synthesized via a MOFs-templating strategy for one-step pyrolysis of bimetallic Ni- Mg@MOFs. The developed Ni/MgO-C catalyst was applied to the hydrogenation of nitroarenes reaction, which exhibited good performance for the hydrogenation of nitroarenes to the corresponding arylamines. The Ni-Mg@MOFs served as a precursor for the preparation of a solid solution catalysts that could improve the dispersion of Ni species, reduce the size of metallic Ni, and strengthen the Ni-MgO interaction, enhance the transfer of electron density. All of these are beneficial for improving the performance of the hydrogenation process. This MOFs-templating strategy may provide a facile method for the synthesis of Ni-MgO solid solution catalyst for other hydrogenation reactions.

Nitrogen heterocycles represent one of the most important units in modern organic chemistry besides their wide existence broadly in natural products, pharmaceuticals, and functional materials. Among these heterocycles, pyrazole, the molecule of the present work, received much attention in organic synthesis because it delivers significant therapeutic and biological values as it was found to be the core unit of many drugs, agrochemicals, and related candidates. Due to this fact, the development of practical methodologies for the preparation of pyrazoles has attracted the long-standing interest of synthetic chemists. Synthetic heterocyclic chemistry using green methods has captivated many researchers in the recent past due to its easy operation and environmentally friendliness. In this review, we summarized systematic approaches for the synthesis of pyrazole derivatives via heterogeneous catalysis, ionic liquid catalysis, and multicomponent reactions.

This review summarized and systematized the currently known methods of substituting phenolic fragments of calix[4]arenes in the para-position, mainly focusing on the conditions of regioselective carrying out such processes. The reactions of the further transformation of the inserted functional groups, which allows the expansion of the family of para-substituted calixarenes, are also considered. These reactions can be used in the synthesis of inherently chiral calix[4]arenes with asymmetric substitution on the upper rim.

The use of herbal remedies is more current in illnesses with chronic diseases. One of these important applications is the usage of many plant-derived compounds as cytotoxic agents for the treatment of cancers. Various research has been done on several species of Pulicaria genus for the evaluation of antihistaminic, antimicrobial, antitumor, antiinflammatory, antioxidant, antibacterial, antifungal, insecticide, and leishmanicidal activities. Some studies have shown that these plants have a rich pool of biometabolites like diterpenes, sesquiterpenes, caryophyllenes, flavonoids, and sesquiterpenoids. The main components in several species of this genus are flavonoids and sesquiterpenoids, which have been identified in chemotaxonomic studies and have shown cytotoxic properties. The Scopus and Science Direct sites were studied to find articles on flavonoid and sesquiterpenoid compounds that have been isolated from the Pulicaria genus. Several biological compounds were isolated from different species of the Pulicaria genus. The main compounds are flavonoids and sesquiterpenoids, which have different biological effects. Its main effect is cytotoxic effect against several cancer cell lines. This study indicates that the Pulicaria genus has cytotoxic activity but posterity studies are needed to probe the active compounds and their possible expansion as novel anticancer drugs.

Here we report the easy synthesis of dendrimer conjugates with four and eight naproxen moieties at the periphery. The synthesis involved two steps protection-deprotection sequence joined with triethylene glycol. A comparison was made between the cytotoxicity of dendron-naproxen conjugates and that of G1.0 G2.0 dendrimer-naproxen conjugates. Cytotoxicity studies showed that dendron conjugates were toxic towards all cancer cell lines studied, and their toxicity was significantly lower than that of dendrimer conjugates. However, dendrimer conjugates showed higher cytotoxicity and selectivity against K-562 and SKLU- 1 than dendron conjugates.

In the current work, we have utilized the reactivity of N-(4-acetylphenyl)-2-(4- formylphenoxy)acetamide for the synthesis of novel series of 1,2-dihydropyridines, Arylidenes, and hydrazides. Our strategies were prolonged for the synthesis of novel terthienylnicotinamidine hydrochloride salt through a Stille coupling reaction of 6-(5'-bromo- [2,2'-bithiophen]-5-yl)nicotinonitrile with 2-tributyltin thiophene followed by treatment with lithium trimethylsilylamide and subsequent hydrolysis. The newly prepared structures were well-elucidated by analytical and spectral data (IR, 1HNMR, ¹³C-NMR, MS, and elemental analysis). The theoretical studies of terthienylnicotinamidine verified that the other atoms that carry a high density of positive values are considered active centers for the electron acceptor. The novel synthesized compounds were efficiently established by spectroscopic data and elemental analysis. The antioxidant activity of the synthesized arylidene, hydrazide, and dihydropyridine compounds was assessed by ABTS•+ free radical assay. The results verified that the transformation of N-(4-acetylphenyl)-2-(4-formylphenoxy)acetamide (47.6%) into hydrazide analogs provided remarkable antioxidant activity (78.1, and 60.3%).