Imidazole‐Based π‐Conjugated Porous Organic Polymer as an Efficient Heterogeneous Photocatalyst: Oxidative Dehydrogenation of N‐Heterocycles and Oxidative Coupling of Benzylamines

Abstract A metal‐free π‐conjugated porous organic polymer (POP), Imd‐POP , was constructed from an imidazole‐integrated pyrene‐based framework, specifically engineered for visible‐light‐driven applications. Owing to its structural robustness, high surface area, and well‐defined porosity, the Imd‐POP facilitates charge separation, oxygen diffusion and efficient reactive oxygen species (ROS) formation due to the thermodynamically favourable conduction band potential for the reduction of O 2 . Imd‐POP enables rapid electron transfer and efficient charge separation, key attributes for high photocatalytic efficiency, and effectively catalyzes the oxidative dehydrogenation (ODH) of a broad array of N ‐heterocycles, affording unsaturated heteroarenes such as quinolines, isoquinolines, indoles, pyridines, and quinazolone derivatives in excellent yields. The catalyst also displays wide functional group tolerance and operates under mild conditions. Aside from ODH transformations, Imd‐POP also facilitates selective oxidation of amines to imines in the presence of molecular oxygen under visible light irradiation. Mechanistic studies suggest that the oxidative dehydrogenation and coupling reactions proceed through photoinduced single‐electron transfer (SET) process involving superoxide anion predominantly. Notably, the catalyst can be easily recovered and reused for at least seven cycles without significant loss of activity. These attributes collectively establish Imd‐POP as a versatile, sustainable, and metal‐free platform for environmentally benign organic synthesis.