A Pyrene Covalent Triazine Framework with TEMPO for Cooperative Photocatalysis: The Selective Oxidation of Amines...

The advancement of efficient photocatalysis represents a critical pathway toward greener chemical transformations. Herein, we develop a system of cooperative photocatalysis that integrates a pyrene covalent triazine framework (Py-CTF) with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and achieves selective oxidation of amines to imines with atmospheric O₂ as the sole oxidant. Py-CTF, with its extended π-conjugated structure and high stability, acts as an effective light-harvesting component; meanwhile, TEMPO serves as a redox mediator to enable efficient electron and proton transfer. Py-CTF photocatalysis integrates with TEMPO (2 mol %) to promote charge separation and transfer, thus leading to a notably enhanced conversion of benzylamine. Cooperative photocatalysis of Py-CTF with TEMPO achieves selective oxidation of diverse benzylamines with performance that compares favorably to most reported systems. Mechanistic studies indicate that superoxide radicals act as the key reactive oxygen species, which are then harnessed by TEMPO to drive the selective oxidation of benzylamines. Moreover, Py-CTF exhibits excellent robustness, maintaining both its performance and structural integrity over multiple reaction cycles. This study highlights the potential of integrating covalent triazine frameworks with redox mediators as a promising platform for more sustainable photocatalysis.