Formation of Fluorinated Amido Esters through Unexpected C3-C4 Bond Fission in 4-Trifluoromethyl-3-oxo-β-lactams

Trifluoromethylated lactams: promising small molecules in the search for effective drugs

Lactams are a crucial class of compounds with broad therapeutic applications, including in the treatment of cancer, diabetes, and infectious diseases. Functionalised lactams are essential core structures in numerous alkaloids and pharmaceuticals. The introduction of fluorine-containing groups, such as a trifluoromethyl (CF3) group, into organic molecules significantly alters their physical and chemical properties. This review highlights the primary biological targets, as well as the most important synthetic pathways, associated with trifluoromethylated β-lactams (four-atom rings), γ-lactams (five-atom rings), δ-lactams (six-atom rings), and ε-lactams (seven atom rings). Furthermore, we analyze the most common lactam scaffolds, evaluating their potential for future chemical synthesis and emphasizing those that merit attention despite having limited reported analogues. This article aims to provide a comprehensive overview of the importance of trifluoromethylated lactams in drug discovery and design.

Synthesis, Reactivity, and Antibacterial Activity of gem-Difluoroalkene, Difluoromethyl, and Trifluoromethyl β-Lactams

New gem-difluoroalkenes were synthesized by the dehydrofluorination of the corresponding 4-CF3-β-lactams. An unexpected rearrangement mechanism of the ester moiety dependent on a stabilizing negative charge was observed. Hydrogenation to 4-CHF2-β-lactams was successful from gem-difluoro-β-lactams.

Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through In Situ Generated Cycloheptenol Derivatives

An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I₂ was the key to the reaction.

α-Unsaturated 3-Amino-1-carboxymethyl-β-lactams as Bacterial PBP Inhibitors: Synthesis and Biochemical Assessment

Innovative monocyclic β-lactam entities create opportunities in the battle against resistant bacteria because of their PBP acylation potential, intrinsically high β-lactamase stability and compact scaffold. α-Benzylidene-substituted 3-amino-1-carboxymethyl-β-lactams were recently shown to be potent PBP inhibitors and constitute eligible anchor points for synthetic elaboration of the chemical space around the central β-lactam ring. The present study discloses a 12-step synthesis of ten α-arylmethylidenecarboxylates using a microwave-assisted Wittig olefination as the crucial reaction step. The library was designed aiming at enhanced β-lactam electrophilicity and extended electron flow after enzymatic attack. Additionally, increased β-lactamase stability and intermolecular target interaction were envisioned by tackling both the substitution pattern of the aromatic ring and the β-lactam C4-position. The significance of α-unsaturation was validated and the R39/PBP3 inhibitory potency shown to be augmented the most through decoration of the aromatic ring with electron-withdrawing groups. Furthermore, ring cleavage by representative β-lactamases was ruled out, providing new insights in the SAR landscape of monocyclic β-lactams as eligible PBP or β-lactamase inhibitors.