Development of Bimetallic g-C3N4 Catalysts for Benzylic C(sp3)-H Oxidation Using Fluorescence-Based High-Throughput Screening Yujin Park Gwangju Institute of Science and Technology

Abstract

Benzylic C(sp3)-H oxidation is an important transformation in synthetic and industrial chemistry, affording valuable carbonyl compounds that serve as key building blocks and pharmaceutical intermediates. Various transition-metal catalysts have been widely employed for this reaction, and recent studies have increasingly focused on utilizing molecular oxygen (O2) from air as an oxidant to achieve more environmentally benign and efficient oxidative transformations. In this study, a heterogeneous catalytic system was developed using catalysts prepared by impregnating transition metals onto graphitic carbon nitride (g-C3N4), which enables facile separation and recovery. A series of bimetallic catalysts was systematically synthesized in parallel, affording a catalyst library to investigate potential synergistic effects between the two metal components. Given the large number of candidates, high-throughput screening (HTS) with a fluorescent substrate was conducted to efficiently evaluate their catalytic performance. The most active catalyst was subsequently selected, and its reaction conditions were optimized. This catalytic system could be applied to a range of substrates, and the catalyst was confirmed to be recoverable and reusable. In addition, the prepared catalysts were characterized by ICP-OES, XRD, XPS, and TEM to investigate their compositions, structure, and morphology.