Bioinspired Flavin-Based Supramolecular Materials for Catalyzing Baeyer-Villiger Oxidation

Area of Science:

• Supramolecular Chemistry
• Biomimetic Catalysis
• Organic Synthesis

Background:

• Baeyer-Villiger (B-V) oxidation is vital for producing value-added chemicals.
• Biomimetic catalysts inspired by Baeyer-Villiger monooxygenase (BVMO) show promise but struggle to replicate enzymatic active sites for versatile lactone synthesis.
• Mimicking the BVMO active site is challenging, especially for low ring-strain lactones like valerolactone derivatives.

Purpose of the Study:

• To design a novel biomimetic catalyst that effectively mimics the BVMO active site.
• To achieve efficient and selective oxidation reactions, including Baeyer-Villiger oxidation, using a supramolecular scaffold.
• To develop a sustainable and industrially relevant platform for chemical synthesis.

Main Methods:

• Designed amphiphilic alkylated arginine surfactants that self-assemble into a guanidinium-terminated micellar scaffold.
• Incorporated arginine and a hydrophobic pocket to mimic the BVMO active site microenvironment.
• Integrated flavin mononucleotide (FMN) and manganese porphyrin centers for electron transfer and cooperative catalysis, utilizing O2 as the sole oxidant.

Main Results:

• The system efficiently oxidized NADH, transferring electrons to FMN and then to manganese porphyrin to generate high-valent Mn-oxo intermediates.
• Selective oxidation of sulfides to sulfoxides achieved yields up to 85% and selectivity over 98%.
• Conversion of cyclopentanone derivatives to lactones yielded up to 46% with 100% selectivity.

Conclusions:

• The designed supramolecular scaffold effectively mimics the BVMO active site, enabling efficient biomimetic catalysis.
• This strategy offers a sustainable and highly selective platform for industrial oxidation reactions, including the synthesis of lactones and sulfoxides.
• The integration of supramolecular design and enzyme mimicry provides a powerful approach for developing advanced catalysts.