The present invention provides novel compounds of Formula (I′) and (I), and pharmaceutically acceptable salts, solvates, hydrates, polymorphs, co-crystals, tautomers, stereoisomers, isotopically labeled derivatives, prodrugs, and compositions thereof. Also provided are methods and kits involving the inventive compounds or compositions for killing a microorganism (e.g., bacteria, fungi, viruses, protozoa, or multicellular parasites), the prevention and/or treatment of infectious diseases (e.g., infections by microorganisms, bacterial infection, cystic fibrosis infection, foreign body infection, urinary tract infection (UTI), or infections leading to biofilms), controlling and/or eradicating biofilms (e.g., bacterial biofilms), preventing biofilm formation, sterilizing a surface, and/or eradicating persister cells (e.g., in a subject in need thereof or in a subject involving a biofilm).