Polystyrene-Supported tBu-4CzIPN as a Recyclable Organic Photocatalyst for Single-Electron and Energy-Transfer Reactions

Abstract A polystyrene-supported 4CzIPN photocatalyst was prepared through Suzuki–Miyaura-based covalent immobilization of a boronate-functionalized 4CzIPN derivative. Introduction of tert-butyl groups afforded PS-tBu-4CzIPN, which exhibited improved operational stability relative to the parent-supported catalyst under repeated-use conditions. The supported catalyst promoted representative visible-light-driven reactions involving single-electron transfer, including decarboxylative cross-coupling and trifluoromethylation/benzylation of styrenes, and retained catalytic competence in energy-transfer-based photoreactions. These results demonstrate that tert-butyl-substituted, polystyrene-supported 4CzIPN can function as a recyclable organic photocatalyst for selected visible-light-driven transformations, although its performance remains reaction dependent.