Synthesis and antitumor activity evaluation of some pyrrolone and pyridazinone heterocycles derived from 3-((2-oxo-5-(p-tolyl)furan-3(2H)-ylidene)methyl)quinolin-2(1H)-one

Iron-Mediated C-H Functionalization of Unactivated Alkynes for the Synthesis of Derivatized Dihydropyrrolones: Regioselectivity Under Thermodynamic Control

Cyclopentadienyliron dicarbonyl-based complexes present opportunities for underexplored disconnections in synthesis. Access to challenging dihydropyrrolone products is achieved by propargylic C-H functionalization of alkynes for the formation of cyclic organoiron species. Excellent regioselectivity for unsymmetrical alkynes is observed in many cases. Notably, regioselectivity under these stoichiometric conditions diverges from those observed previously under catalysis, occurring at the more-substituted terminus of the alkyne, allowing for methine functionalization and the formation of quaternary centers. Divergent demetallation of the intermediate organoiron complexes gives access to chemically diverse products which are amenable to further functionalization.

Synthesis and antioxidant, antimicrobial, and antiviral activity of some pyrazole-based heterocycles using a 2(3H)-furanone derivative

Some pyrazole-based heterocycles such as pyrrolone, pyridazinone, and imidazole derivatives were synthesized utilizing the pyrazolyl-2(3H )-furanone derivative 3 , which was obtained in a good yield via Perkin condensation of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole with 3-(4-methylbenzoyl)propionic acid in the presence of cyclo-dehydrating agent (sodium acetate and acetic anhydride). Also, the acid hydrazide obtained was reacted with some carbonyl reagents such as acetic anhydride, benzoyl chloride, 4-chlorobenzaldehyde, and 1,3-diphenyl-4-formylpyrazole, aiming to achieve new pyrrolone derivatives. The antioxidant, antimicrobial, and antiviral activity screening of some synthesized compounds demonstrated that some of them offered strong potencies. An experimental trial was undertaken to explore the effect of different substances and applied against avian influenza HPAI-H5N1 (AIV) to evaluate the antiviral replication in specific pathogen-free chicken embryos. All the compounds were screened for their antimicrobial activities, and most of tested compounds showed potent inhibition growth activity toward Haemophilus (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria), and Candida albicans fungus. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Staphylococcus aureus , Haemophilus , and Candida albicans as compared to standard drugs. This experiment shows the potential usage of these compounds as antiviral agents and can be considered as a viable means to control the economically important avian influenza of poultry. These compounds can thus be recommended for their antiviral, antibacterial, and antifungal property and can very well be used as immunostimulants.

Synthesis, SAR studies, and insecticidal activities of certain N-heterocycles derived from 3-((2-chloroquinolin-3-yl)methylene)-5-phenylfuran-2(3H)-one against Culex pipiens L. larvae

An acid hydrazide derivative was synthesized and transformed into a variety of valuable N-heterocycles such as pyridazinone, oxadiazole, triazolopyridazinone, and triazole derivatives via reactions with certain carbon electrophiles such as 4-methoxybenzaldehyde, indole-3-carbaldehyde, pentan-2,4-dione, and carbon disulfide. The chemical structures of all prepared compounds were verified via their analytical and spectroscopic data. The insecticidal activity of the N-heterocycles was evaluated against field and lab strains of the third larval instar of Culex pipiens. All tested compounds exhibited higher larvicidal activity against the lab strains compared to the field strains, with dissimilar ratios. The obtained results demonstrate that the high toxicity achieved by oxadiazole followed the order of furanone, pyridazinone and hydrazide, with lower LC₅₀ values of the hydrazone and N-acetylpyridazinone derivatives compared to that of imidacloprid. Interestingly, these compounds are promising agents for insect pest control, especially since they are insoluble in water and can overcome the disadvantages of neonicotinoid applications in pest management programs.

A new series of N-heterocycles including pyridazinone, oxadiazole, triazolopyridazinone, and triazole derivatives were synthesized from the acid hydrazide via its reaction with certain carbon electrophiles.

Synthesis, DFT, and eco-friendly insecticidal activity of some N-heterocycles derived from 4-((2-oxo-1,2-dihydroquinolin-3-yl)methylene)-2-phenyloxazol-5(4H)-one

A new series of nitrogen heterocycles encompassing a quinoline scaffold such as imidazolone, benzimidazole, triazinone, triazole, and thiazole derivatives was synthesized utilizing the readily obtainable building block synthon, 4-((2-oxo-1,2-dihydroquinolin-3-yl)methylene)-2-phenyloxazol-5(4H)-one (3). It was interesting that the fused heterocycle, pyranoquinoline derivative 15 was successfully synthesized by different routes of reactions. The synthesized compounds were evaluated for their insecticidal activity and compounds 6, 17, and 20 were the most potent against both Mythimna separata and Nilaparvata lugens. The DFT study was performed for the most potent compounds.

Bioactive Secondary Metabolites of the Genus Diaporthe and Anamorph Phomopsis from Terrestrial and Marine Habitats and Endophytes: 2010-2019

The genus Diaporthe and its anamorph Phomopsis are distributed worldwide in many ecosystems. They are regarded as potential sources for producing diverse bioactive metabolites. Most species are attributed to plant pathogens, non-pathogenic endophytes, or saprobes in terrestrial host plants. They colonize in the early parasitic tissue of plants, provide a variety of nutrients in the cycle of parasitism and saprophytism, and participate in the basic metabolic process of plants. In the past ten years, many studies have been focused on the discovery of new species and biological secondary metabolites from this genus. In this review, we summarize a total of 335 bioactive secondary metabolites isolated from 26 known species and various unidentified species of Diaporthe and Phomopsis during 2010-2019. Overall, there are 106 bioactive compounds derived from Diaporthe and 246 from Phomopsis, while 17 compounds are found in both of them. They are classified into polyketides, terpenoids, steroids, macrolides, ten-membered lactones, alkaloids, flavonoids, and fatty acids. Polyketides constitute the main chemical population, accounting for 64%. Meanwhile, their bioactivities mainly involve cytotoxic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anti-algae, phytotoxic, and enzyme inhibitory activities. Diaporthe and Phomopsis exhibit their potent talents in the discovery of small molecules for drug candidates.