Traceless Staudinger Ligation To Introduce Chemical Diversity on β‑Lactamase Inhibitors of Second Generation

We explored the traceless Staudinger
ligation for the functionalization
of the C2 position of second generation β-lactamase inhibitors
based on a diazabicyclooctane (DBO) scaffold. Our strategy is based
on the synthesis of phosphine phenol esters and their ligation to
an azido-containing precursor. Biological evaluation showed that this
route provided access to a DBO that proved to be superior to commercial
relebactam for inhibition of two of the five β-lactamases that
were tested.