Synthesis and Antibacterial Evaluation of Cephalosporin Isosteres

Abstract As part of a program to explore the chemistry of β‐lactams and their derivatives, we prepared a focused set of benzazetidine, indoline, and indole heterocycles, as well as flexible unconstrained variations of the four‐membered heterocyclic compounds. These analogues mimic the three‐dimensional shape of cephalosporins but are not prone to covalent binding via ring opening. Although these analogues were inactive against the ESKAPE pathogens and Mtb , they represent unique and underexplored chemotypes for future biological screening.