Design of peptide-containing 5-unmodified neutral flavins that catalyze aerobic oxygenations.

Simulation of the monooxygenation function of flavoenzyme () has been long-studied with 5-modified cationic flavins ( ), but never with 5-unmodified neutral flavins () despite the fact that is genuinely equal to the active center of . This is because of the greater lability of 4a-hydroperoxy adduct of , , compared to those of , , and , . In this study, incorporated into a short peptide, flavopeptide (), was designed by a rational top-down approach using a computational method, which could stabilize the corresponding 4a-hydroperoxy adduct () through intramolecular hydrogen bonds. We report catalytic chemoselective sulfoxidation as well as Baeyer-Villiger oxidation by means of under light-shielding and aerobic conditions, which are the first -mimetic aerobic oxygenation reactions catalyzed by under non-enzymatic conditions.