A convenient synthesis of 2-azetidinones via 2-fluoro-1-methylpyridinium p-toluenesulfonate

Anticancer activity and evaluation of apoptotic genes expression of 2-azetidinones containing anthraquinone moiety

Nowadays, one of the principal causes of death in the world is cancer. A series of 2-azetidinones containing anthraquinone moiety with various substituents were synthesized using [2 + 2] ketene-imine cycloaddition (Staudinger ketene-imine cycloaddition), and their cytotoxicity against some human cancer and normal cell lines was evaluated. Some of these hybrid compounds showed moderate to significant cytotoxicity against breast carcinoma (MCF7), colon carcinoma (HCT116), prostate carcinoma (PC3), and neuroblastoma (SKNMC) cell lines via MTT assay. Surprisingly, hybrid 4gh with the best anticancer activity demonstrated very good antibacterial and antifungal activities. This compound was selected to study to test on human fibroblast (Hu02) normal cell and comparison with doxorubicin. While 2-azetidinone 4gh represented similar cytotoxicity against cancer cell lines compared to doxorubicin, the 2-azetidinone demonstrated lower cytotoxicity against human fibroblast (Hu02) than doxorubicin. Further real-time PCR investigation displayed the expression of Bcl-xl, KI-67, TPX2 and BAX genes were significantly increased or decreased as desired in the cancer cell lines studied by treatment with doxorubicin or 2-azetidinone-anthraquinone 4gh. Molecular docking studies represented that hybrid 4gh strongly fitted the active site of topoisomerase II (PDB 4G0V) with hydrogen bond and hydrophobic interactions.

Synthesis and antimicrobial activities of some novel diastereoselective monocyclic cis-β-lactams using 2-ethoxy carbonyl DCPN as a carboxylic acid activator

A series of novel monocyclic cis-β-lactams were prepared from phenoxyacetic acid as ketene source and imines derived from 1-chloro-3,4-dihydronaphthalene-2-carbaldehyde and respective amine using ethyl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylate (or 2-ethoxy carbonyl DCPN) as a carboxylic acid activator. This is the first time 2-ethoxy carbonyl DCPN has been used as an acid activator in synthesis of β-lactams. The reaction was entirely diastereoselective leading to the formation cis-β-lactam derivatives. These newly synthesized cis-β-lactam were fully characterized by FT-IR, 1H NMR, 13C NMR, HRMS, CHNS and X-ray crystallography study. All this novel compound was also evaluated for their antibacterial and antifungal activities against certain strains of Gram-positive bacteria, Gram-negative bacteria and fungi. These compounds displayed moderate activity against using bacterial and fungal strains.

The facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus

We developed a facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus through a ketene-imine [2+2] cycloaddition reaction of acyl chloride and different Schiff bases.

CuFe2O4 nanoparticles catalyze the reaction of alkynes and nitrones for the synthesis of 2-azetidinones

The reaction of alkynes and nitrones (Kinugasa reaction) in the presence of magnetically recoverable CuFe₂O₄ nanoparticles as a highly efficient heterogeneous catalyst under a mild condition for the synthesis of various 2-azetidinones was reported.

Synthesis, in vitro biological evaluation and in silico molecular docking studies of novel β-lactam-anthraquinone hybrids

Schiff bases from 2-aminoanthraquinone have been prepared by reaction with aldehydes and used to prepare novel β-lactam-anthraquinone hybrids via [2+2] ketene-imine cycloaddition (Staudinger reaction) reaction. In vitro antibacterial studies of all synthesized compound were carried out against three gram-positive strains Staphylococcus aureus (Methicillin-resistant strain), Enterococcus faecium (Vancomycin-resistant strain) and Bacillus subtilis, and two gram-negative strains Escherichia coli and Pseudomonas aeruginosa. These compounds were further evaluated for their in vitro antifungal activity against Candida albicans, Aspergillus niger and Trichophyton mentagrophytes. Hybrid compounds showed moderate to excellent antibacterial and antifungal activities. Surprisingly, among the tested compounds, some of them revealed equal antibacterial and antifungal properties and even better than standards. In addition, results demonstrated that the new hybrids are very promising antibacterial agents against resistant strains. Also molecular docking studies were carried out by Autodoc software. Penicillin-binding protein 2a (PDB ID: 1VQQ) from methicillin-resistant Staphylococcus aureus strain used as a target which good binding interactions were observed.

Application of magnetic Fe3O4nanoparticles as a reusable heterogeneous catalyst in the synthesis of β-lactams containing amino groups

The catalytic activity of magnetic Fe₃O₄nanoparticles to promote the reduction of β-lactams containing nitroaryl groups to β-lactams containing aminoaryl groups in ethanol was reported. This methodology is convenient and green.

Tosylimidazole-mediated one-pot synthesis of 2-azetidinones

Cyclocondensation of Schiff bases and substituted acetic acid with tosylimidazole afforded 2-azetidinones in good to excellent yields. This reaction works reliably well for monocyclic and spirocyclic 2-azetidinones. This reaction is green and efficient and the products can be purified by simple crystallisation.

Facile Synthesis of β-Lactam Derivatives by the Staudinger Reaction Using 3,6-Dichlorotetrazine

A versatile and convenient method for synthesis of β-lactams using 3,6-dichlorotetrazine as an acid activator in the ketene–imine cycloaddition is reported. Monocyclic and spirocyclic β-lactams are obtained in good to excellent yields. Easy purification of the products can be performed by aqueous workup and then crystallisation from ethyl acetate.