Near-Infrared Light-Driven Selective Difunctionalization of Diazo Compounds Enabled by Anthraquinone-Based Conjugated Porous Polymers
Hong-Min Lin, Kun Li, Xiaotong Li, Xiaochen Liu, Fuxing Yang, Fei‐Hu Cui, Haitao Tang, Ying‐Ming Pan, Yu‐Mei Lin
Abstract
The selective functionalization of molecular skeletons driven by near-infrared (NIR) light offers unique advantages due to its mild photochemical properties. However, the scarcity of efficient NIR photocatalysts has severely hindered the development and application of NIR photochemistry in organic synthesis. Herein, we present a conjugated porous polymer (CPP, AQ-TVPE-CPP) capable of absorbing NIR light through the strategic incorporation of anthraquinone (AQ) and tetraphenylethylene (TPE) units into a π-conjugated framework. Charge localization induced by donor–acceptor (D-A) interactions and a coplanar configuration enforced by the anchoring effect of four vinyl linkers endow AQ-TVPE-CPP with good photoelectric properties and high stability. Exploiting this material, we achieve NIR light-driven selective difunctionalization of diazo compounds without requiring additives or cocatalysts, enabled by spatially separated oxidation and reduction centers generated through electron–hole pairs. The NIR photothermal effect of AQ-TVPE-CPP significantly accelerates the reaction, effectively compensating for the slow kinetics typically associated with low-energy NIR photons. This three-component difunctionalization tolerates challenging substrates, including azacyclic compounds bearing free amino, carboxyl, or hydroxyl groups. NIR penetration experiments validate both the deep-tissue penetration capability of NIR light and the catalyst’s recyclable performance under demanding conditions. This recyclable, metal-free, and highly stable heterogeneous catalyst demonstrates the significant advantages and great application potential of conjugated porous polymers for harnessing NIR light in complex synthesis reactions.