Development and fabrication of a sustainable and recyclable COF-366-LP@Cu modified SPE electrode for the enantioselective electro-carboxylation of 1-phenylethan-1-ols to synthesize (S)-2-phenylpropanoic acid derivatives under mild reaction conditions

Abstract

Carbon dioxide (CO₂), a major industrial by-product, poses significant environmental challenges, highlighting the need for efficient strategies to convert it into value-added products. Although extensive research has explored chemical and electrochemical CO₂ utilization, many existing methods rely on toxic reagents, costly metals, and harsh reaction conditions, limiting their scalability and commercial applicability. To address these challenges, this study develops a novel enantioselective electrocatalytic system using COF-366 modified with L-proline and coated with low-cost Cu metal, overcoming limitations of prior methods that rely on toxic reagents, expensive metals, and harsh conditions. The integrated design leverages COF-366 as a CO₂ adsorptive matrix, Cu as the active catalytic center, EG/ChCl as a dual solvent-electrolyte, and L-proline as the chiral inducer, enabling efficient electro-organic carboxylation of 1-phenylethan-1-ols 1(a-m) with CO₂ 2(a) to yield phenylpropanoic acid derivatives 3(a-m) with 90–97% yields under mild, sustainable conditions of room temperature, atmospheric pressure, 1-hour reaction time, and 10 mA applied current. The COF-366-LP@Cu catalyst and EG/ChCl DES exhibit excellent reusability over 10 cycles with minimal activity loss and are comprehensively characterized by FT-IR, SEM, EDS, BET, TGA, XPS, and CV, while products are confirmed via melting point, ¹H/¹³C NMR, and CHN elemental analyses.