The shift toward mild, low-impact chemical conversion is pivotal for future development. Photocatalytic energy conversion, which harnesses light to drive reactions under mild conditions, offers a powerful alternative to conventional energy-intensive synthetic routes. Here, we establish mesoporous graphitic carbon nitride (mpg-CN) as a highly efficient, metal-free photocatalyst for the selective oxidation of benzylic substrates, using cumene as a representative example. Optimized conditions enabled the selective oxidation of cumene to acetophenone and 1-methoxyethylbenzene with high efficiency, underscoring the catalyst’s reaction selectivity and synthetic value. The system readily accommodates structurally related substrates with radical stability and steric hindrance playing defining roles in reactivity. Sensitivity analyses revealed critical parameters governing reaction performance, while spin-trapping experiments under oxygen-rich conditions identified hydroperoxide radicals as key intermediates initiating α-carbon oxidation. Notably, scaling the reaction 10-fold preserved 66% conversion and 70% selectivity, and a further scale-up to gram scale of precursor delivered 50% acetophenone after 72 h. Furthemore, solvent recovery and reuse maintained high catalytic efficiency over the initial reuse cycles, demonstrating the operational durability of the system. Collectively, these findings position mpg-CN as a robust, scalable, and metal-free photocatalyst, a compelling platform for next-generation chemical manufacturing.
Żółtowska et al. (Mon,) studied this question.