Broad spectrum beta-lactamase inhibitors

A compound of formula:

• or pharmaceutically acceptable salts thereof,
• wherein:
• R is an acylamino group;
• R1, R2, and R4 are independently selected from hydrogen, halogen, a C1-C6 alkyl group, a C1-C6 alkoxy group and —S-alkyl, where the alkyl group is a C1-C6 alkyl;
• n is 1 or 2;
• Y is O—C+ or OR3, where R3 is hydrogen, an alkyl group or an aryl group, each of which groups is optionally substituted, and C+ is a pharmaceutically acceptable cation;
• M is selected from:
• where:
• each R8 is independently selected from hydrogen, halogen, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C7-C19 aralkyl group, a 3-7-member ring cyclic hydrocarbon group, a 3-7 member heterocyclic group, a C6-C10 aromatic group, and a 6-10 member heterocyclic aromatic group, wherein each of said groups is optionally substituted;
• and
• X is a leaving group;
• wherein optional substitution is substitution with one or more halogen, hydroxyl, —CN, —SH, alkyl, alkenyl, alkynyl, aryl, heterocyclyl, heteroaryl, alkoxy, alkenoxy, alkynoxy, aryloxy, heteroaryloxy, heterocyclyloxy, sulfenyl, sulfonyl, sulfonate, amine, amido, aminoacyl, imine, —COR20, —COOR20, —CON(R20)2, —OCOR20, —OCN(R20)2, haloalkyl, haloalkenyl, haloaryl, —NR20COR20, —NR20COOR20, or —COO− C+, where each R20 is selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heterocyclyl, and heteroaryl, and C+ is a pharmaceutically acceptable cation.