A 2D sp² Carbon Conjugated Pyrene Covalent Organic Framework with TEMPO for Selective Photocatalysis

Abstract With recent developments, covalent organic frameworks (COFs) have attracted considerable attention in various applications, including visible light photocatalysis. Considering the properties of pyrene planum and π‐electron conjugation, 2D sp² carbon‐conjugated and imine‐linked pyrene COFs, Py‐sp²c‐COF and Py‐COF are synthesized with a well‐ordered crystalline structure. Py‐sp²c‐COF is significantly superior to Py‐COF for selective photocatalysis due to the sp² carbon conjugation. By virtue of the porosity and activity, Py‐sp²c‐COF with TEMPO ((2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl) turns out to be effective for selective aerobic oxidation of amines to imines induced by green light. Substantially, 2 mol% of TEMPO, an electron–proton transfer mediator, facilitates the aerobic conversions of amines by Py‐sp²c‐COF photocatalysis. It is an ingenious design for selective organic transformations by cooperative photocatalysis of an sp² carbon‐conjugated COF with a redox mediator.