Expedient on-resin synthesis of peptidic benzimidazoles

The benzimidazole moiety is a ubiquitous pharmacophore present in numerous anthelmintic, antibacterial, antiviral, antineoplastic, and antifungal drugs. While the polypharmacology of this heterocycle has spurred the development of numerous solution-phase syntheses, only a handful of disparate and inefficient methods detailing its synthesis on-resin have been reported. Here we report the concise and expedient syntheses of internal and C-terminal peptidic benzimidazoles - an emerging class of peptide deformylase (PDF)-inhibiting antimicrobials. This method benefits from being performed wholly on solid-phase at room temperature resulting in minimal purification and tolerance of temperature-sensitive functionality.