Enhancing the catalytic activity of photosensitizers is critical for photocatalysis, especially in dual catalytic systems. We present the integration of N-aryl phenoxazine photosensitizers and nickel-bipyridine catalysts into linear and cross-linked polyacrylate matrices, creating robust polymer-supported dual photocatalysts. The linear flexible polymer confers good solubility in organic solvents to ensure efficient interactions between catalytic sites and substrates. The proximity of phenoxazine units and nickel complexes in the linear copolymer P1-Ni boosts electron, energy, and radical transfers, significantly enhancing the catalytic activity of phenoxazine photosensitizers. P1-Ni exhibits high activity in catalyzing visible-light-driven sulfonylation, esterification, and etherification reactions across a broad substrate scope at extraordinarily low catalyst loadings (0.1 to 0.2 mol %) and with exceptionally high turnover numbers approaching 1000. P1-Ni outperforms its homogeneous control by 27- to 38-fold. Additionally, an insoluble cross-linked polymer catalyst (P2-Ni) was synthesized by incorporating a divinyl cross-linking agent. P2-Ni swells in organic solvents, displays activity comparable to that of P1-Ni, and is readily recovered via centrifugal separation and used in six catalytic cycles with minimal loss of activity. This work demonstrates the ability of polymer supports to enhance the activities of organic photosensitizers in photocatalytic organic transformations by facilitating electron, energy, and/or radical transfers.

中文翻译：

---

在聚合物载体中掺入正芳基吩噁嗪光敏剂和镍催化剂可增强光催化有机转化


增强光敏剂的催化活性对于光催化至关重要，尤其是在双催化系统中。我们介绍了将 N-芳基吩噁嗪光敏剂和镍-联吡啶催化剂整合到线性和交联聚丙烯酸酯基质中，从而创建强大的聚合物负载双光催化剂。线性柔性聚合物在有机溶剂中具有良好的溶解性，以确保催化位点和底物之间的有效相互作用。线性共聚物 P1-Ni 中吩噁嗪单元和镍络合物的接近促进了电子、能量和自由基转移，显着增强了吩噁嗪光敏剂的催化活性。P1-Ni 在极低的催化剂负载量（0.1 至 0.2 mol%）和接近 1000 的极高周转数下，在广泛的底物范围内催化可见光驱动的磺酰化、酯化和醚化反应中表现出高活性。P1-Ni 的性能是其均相对照的 27 至 38 倍。此外，通过掺入二乙烯基交联剂合成了不溶联聚合物催化剂 （P2-Ni）。P2-Ni 在有机溶剂中溶胀，表现出与 P1-Ni 相当的活性，并且很容易通过离心分离回收，并在六个催化循环中使用，活性损失最小。这项工作证明了聚合物载体通过促进电子、能量和/或自由基转移来增强光催化有机转化中有机光敏剂活性的能力。