One‐Pot Multicomponent Synthesis of β‐Lactams via In Situ Generated Imines

Abstract

An efficient, atom‐economic, multi‐component reaction protocol has been developed for the synthesis of β‐lactams. This new procedure employs a one‐pot sequential multicomponent Staudinger reaction between acetic acid derivatives and imines generated in situ by thermal melting of an aryl or heteroaryl aldehyde with the primary amine. The protocol has the merits of simple operation, short reaction time, convenient work‐up, good yields, applicability to a broad range of substrates, cheap and less hazardousness to humans and environment. The structures of the β‐lactam adducts E1‐30 were characterized by spectral (FT‐IR, 1H‐NMR, 13C‐NMR, GC‐MS) and elemental analyses.

Sulfonamide‐β‐lactam Hybrids Incorporating the Piperazine Moiety as Potential Antiinflammatory Agent with Promising Antibacterial Activity

“…In the 1 H-NMR spectra, the observed coupling constants of the vicinal H-3 and H-4 protons of the β-lactam ring confirmed the cis stereochemistry of these new βlactam compounds. Based on our experimental results [59][60][61] and the literature data, [62][63][64] the plausible mechanism for the stereoselective formation of cis-β-lactam ring is shown in Scheme 3. In the first step of the reaction, the nucleophilic exo-attack of the imine (B) nitrogen to the ketene (A) results in zwitterionic intermediate (C), following direct conrotatory ring closure to yield cis β-lactam isomer (D).…”