Imitation of ß-lactam binding enables broad-spectrum metallo-ß-lactamase inhibitors.

Carbapenems are vital antibiotics, but their efficacy is increasingly compromised by metallo-ß-lactamases (MBLs). Here we report the discovery and optimization of potent broad-spectrum MBL inhibitors. A high-throughput screen for NDM-1 inhibitors identified indole-2-carboxylates (InCs) as potential ß-lactamase stable ß-lactam mimics. Subsequent structure-activity relationship studies revealed InCs as a new class of potent MBL inhibitor, active against all MBL classes of major clinical relevance. Crystallographic studies revealed a binding mode of the InCs to MBLs that, in some regards, mimics that predicted for intact carbapenems, including with respect to maintenance of the Zn(II)-bound hydroxyl, and in other regards mimics binding observed in MBL-carbapenem product complexes. InCs restore carbapenem activity against multiple drug-resistant Gram-negative bacteria and have a low frequency of resistance. InCs also have a good in vivo safety profile, and when combined with meropenem show a strong in vivo efficacy in peritonitis and thigh mouse infection models.

Asymmetric Synthesis of 1,3-Diamines. II: Diastereoselective reduction of atropisomeric N-tert-butanesulfinylketimines.

Chiral, nonracemic o-aminobenzylamines were prepared in a highly diastereoselective reduction of atropisomeric N-tert-butanesulfinylketimines. The ortho-substituent ensures the distinct reactivity of atropisomers 4d-f. The free energy of activation for atropisomerization of sulfinylimines 4d-f in THF-d(8) was determined by NMR methods to range from 70.8 to 97.9 kJ/mol.

Asymmetric synthesis of 1,3-diamines by diastereoselective reduction of enantiopure N-tert-butanesulfinylketimines: unusual directing effects of the ortho-substituent.

Chiral, nonracemic 1,3-diamines were prepared in a highly diastereoselective reduction of diaryl N-tert-butanesulfinylketimines. Correlation between facial selectivity of the reduction and E or Z geometry of the starting ketimines suggests involvement of a cyclic transition state for the reduction. The ortho-substituent controls the geometry of N-tert-butanesulfinylketimines in the solid state and provides additional stabilization of the cyclic transition state.