Covalent organic frameworks (COFs) with photoactive units have attracted significant interest in visible light photocatalysis and can present a metal-free scenario for activating O₂. As a typical photoactive unit, thiazolo[5,4-d]thiazole (TzTz) has rarely been added to COFs. However, circumventing the low reversibility of TzTz, it could be embedded into the building blocks beforehand, along with other bonds like β-ketoenamine in forming COFs. TzTz was embedded into 1,1′-biphenyl-4,4′-diamine (BD) using this approach to produce 4,4′-(TzTz-2,5-diyl)dianiline (DTz). Under organobase-modulated solvothermal conditions, combining 1,3,5-triformylphloroglucinol (Tp) with BD and DTz resulted in the production of β-ketoenamine-linked TpBD-COF and TpDTz-COF. Both TpDTz-COF and TpBD-COF are microspheres. TpDTz-COF possessed more adequate separation and charge migration than TpBD-COF. This resulted in superior performance for the blue light photocatalytic selective oxidation of benzylamine with O₂. Furthermore, with O₂ as the main oxidant, a wealth of benzylamines could be converted into imines over TpDTz-COF. Mechanistic investigations substantiate that oxidation of benzylamines obeys an electron transfer pathway, in which superoxide anion (O₂^•–) is the crucial reactive oxygen species. This study highlights the superiority of TzTz-embedded COFs in developing effective photocatalytic systems for organic transformations.

具有光活性单元的共价有机框架（COFs）在可见光光催化中引起了极大的兴趣，并且可以呈现一种无金属活化O ₂的场景。作为典型的光活性单元，噻唑并[5,4- d]噻唑 (TzTz) 很少被添加到 COF 中。然而，为了避免 TzTz 的低可逆性，它可以与其他键（如 β-酮烯胺）一起预先嵌入到构建单元中，以形成 COF。使用这种方法将 TzTz 嵌入 1,1'-联苯-4,4'-二胺 (BD) 中以生产 4,4'-(TzTz-2,5-二基)二苯胺 (DTz)。在有机碱调节的溶剂热条件下，将 1,3,5-三甲酰基间苯三酚 (Tp) 与 BD 和 DTz 结合可生成 β-酮烯胺连接的 TpBD-COF 和 TpDTz-COF。TpDTz-COF 和 TpBD-COF 都是微球。TpDTz-COF比TpBD-COF具有更充分的分离和电荷迁移。这导致苄胺与O ₂的蓝光光催化选择性氧化的优异性能。此外，与 O ₂作为主要氧化剂，大量的苄胺可以通过 TpDTz-COF 转化为亚胺。机理研究证实苄胺的氧化遵循电子转移途径，其中超氧阴离子（O ₂ ^•–）是关键的活性氧物质。本研究强调了嵌入 TzTz 的 COF 在开发用于有机转化的有效光催化系统方面的优势。