Self-assembled Cationic Poly (Thioctic acid)/Flavin-based Catalysts for Biomimetic Baeyer-Villiger Oxidation

In this study, we present a Baeyer-Villiger monooxygenase (BVMO)-mimetic catalyst, created through the self-assembly of a degradable arginine-tethered poly (thioctic acid) (pGTA) scaffold with flavin mononucleotide (FMN), driven by electrostatic and hydrophobic interactions. The cationic pGTA scaffold not only facilitated efficient nicotinamide adenine dinucleotide (NADH) access to the FMN center, but also incorporated arginine aiming to stabilize the peroxo intermediate, mimicking the microenvironment of the active site of BVMOs. The self-assembly is confirmed through ¹H-NMR, fluorescence quenching, transmission electron microscopy, the zeta potential, and molecular dynamics simulations. The FMN-based supramolecular catalysts effectively catalyzed NADH oxidation, followed by BV oxidation of cycloketones (including bicyclo[3.2.0]hept-2-en-6-one, 2-phenylcyclobutanone and 3-phenylcyclobutanone) to yield the corresponding lactone with high selectivity. The system demonstrated excellent activity under mild, oxygen-driven conditions, and its performance is further enhanced upon heating. This work provides a promising strategy for designing environmentally friendly biomimetic catalysts with minimal reliance on toxic reagents, advancing green chemistry and sustainable industrial processes.