Synthesis of β-Lactams from Acids and Imines Using Thiocarbonyldiimidazole

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.

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.

Cerium(IV) Tetrabutylammonium Nitrate (CTAN): A Mild and Efficient N-dearylation Agent for Synthesis of N-unsubstituted 2-azetidinones

A simple and efficient protocol for the conversion of N-p-methoxyphenyl, N-p-ethoxyphenyl, N-p-methoxynaphthyl, N-3,4-dimethoxybenzyl and N-p-methoxybenzyl-2-azetidinones to N-unsubstituted 2-azetidinones using cerium(IV) tetrabutylammonium nitrate (CTAN) in dichloromethane is described. The method is compatible with a number of functional groups, and N-unsubstituted 2-azetidinones can be prepared under mild conditions at room temperature. The reaction is rapid, and pure products are obtained in good yields.

An ionic liquid promoted approach to bitriazolyl compounds as succinate–ubiquinone oxidoreductase inhibitors

Bitriazolyl compounds, a novel skeleton that is totally different from existing commercialized SQR-inhibiting fungicides, could provide a new lead for further development of SQR inhibitors.

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.

1-(Morpholin-4-yl)-4-(2-nitro-phen-yl)spiro-[azetidine-3,9'-xanthen]-2-one

In the title compound, C22H21N3O5, the β-lactam (azetidin-2-one) ring is nearly planar [maximum deviation = 0.010 (1) Å] and makes dihedral angles of 69.22 (5), 55.32 (5) and 89.42 (4)° with the least-squares planes formed by the four C atoms of the morpholine ring, which adopts a chair conformation, the benzene ring and the xanthene ring system, respectively. In the crystal, C-H⋯O hydrogen-bond contacts connect neighbouring mol-ecules into infinite zigzag chains running parallel to the b axis.