Beta-lactamase inhibitors

摘要

Substituted bicyclic beta-lactams of Formula I: (I), are ß-lactamase inhibitors, wherein a, X, R and R are defined herein. The compounds and pharmaceutically acceptable salts thereof are useful in the treatment of bacterial infections in combination with ß-lactam antibiotics. In particular, the compounds can be employed with a ß-lactam antibiotics (e.g., imipenem, piperacillin, or ceftazidime) against microorganisms resistant to ß-lactam antibiotics due to the presence of the ß-lactamases.