Development of a green electrode based on fullerene oxide functionalized with L-alanine and MIL101@Fe MOFs for enantioselective electro-organic carboxylation in NaCl electrolyte

Abstract

Conventional synthetic methods for organic compounds are associated with significant environmental concerns, primarily due to the reliance on metal-based catalysts. Furthermore, the employment of toxic solvents combined with prolonged reaction durations presents substantial obstacles to the commercial scalability and practical application of these approaches. In this study, we developed a sustainable green electrode by functionalizing fullerene oxide with L-alanine and incorporating MIL-101@Fe metal–organic frameworks. This innovative approach is designed for enantioselective electro-organic carboxylation in a NaCl electrolyte. The study examines how the biocompatibility of L-alanine and the structural robustness of MIL-101@Fe enhance catalytic efficiency while maintaining environmental sustainability. Functionalizing fullerene oxide with L-alanine improves the electrode's selectivity for the desired enantiomers and increases electron transfer efficiency. The resulting catalytic substrate, oxC60-Ala-MIL101@Fe, was characterized employing various analytical techniques, including EDX, TGA, SEM, EDS, BET, CV, XPS, FT-IR, and DFT calculation to assess its morphology, thermal stability, elemental composition, surface area, and electrochemical behavior. To evaluate the electrode’s performance, we conducted the electro-organic carboxylation of ethylbenzene 1(a-l) derivatives under electro-organic synthesis conditions, yielding various (R)-2-phenylpropanoic acids 4(a-l) with excellent yields (92–97%). Optimal results were obtained at a current of 10 mA, over a duration of 2 h, and at room temperature and Ala-MIL101@Fe exhibited good performance for up to 9 cycles. The products were confirmed using ¹HNMR, CHN analysis, FT-IR spectroscopy, and melting point determination.

Graphical abstract