P-Lactams complexes

Figure 5 A penicillin-binding activity-based high-throughput SPA assay for the identification of potential inhibitors of the transpeptidase activity of PBPs. A particular PBP of interest is first labeled with biotin. The biotinylated PBP is then mixed with a 3H-labeled P-lactam in 96-well microtiter plates and the reaction mixtures are incubated at room temperature for a period of time. After incubation, the biotionylated PBP-3H-P-lactam complexes are captured by mixing with streptavidin coated SPA beads. The P-lactam-binding activity of the PBP is measured by counting the microtiter plates after mixing with the SPA beads.

Fig. 29 Structurally characterized binuclear zinc P-lactam complexes having P-lactam carbonyl coordination.

Alkylideneamido complex [Re(N=CPh2)(CO)3(bpy)] [80] has been reported to react with ketene to afford, via Staudinger reaction, a single p-lactam complex whose structure was determined by X-ray diffraction [75]. The p-lactam complex reacted with methyl triflate (CH30Tf), affording the free Ai-methyl-p-lactam and the complex used as precursor (Scheme 21), [81]. 

Similarly, ketene generated from acid chloride by treatment with triethyl-amine reacted with tricarbonylchromium-complexed benzaldimines to afford P-lactam derivatives via [2+2] cycloaddition with high diastereoselectivity. Thus, the cycloaddition of benzaldimine chromium complexes with ketenes generated from acid chloride at 0 °C in the presence of triethylamine afforded czs-p-lactam as a single diastereomer 27 (Eq. 20) [19]. Remote positioned imine having the planar chiral arene chromium complex was also reacted with ketene to afford p-lactam complex as diastereomeric mixture (Eq. 21) [19]. 

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