Zirconium Photocatalysis for Direct C−H Functionalization, Decarboxylative Amination, and Polystyrene Oxidative Degradation

Zirconium is an earth-abundant, environmentally benign, and biocompatible element, yet its role in organic synthesis has largely been limited to transformations of active substrates like alkenes and alkynes. The direct catalytic functionalization of inert yet abundant feedstocks, including alkanes, free aliphatic acids, and nonpolar polymers such as polystyrene (PS), remains a formidable challenge. Herein, we report that commercially available ZrCl4 exhibits potent ligand-to-metal charge transfer (LMCT) reactivity under light irradiation, establishing a unified photocatalytic platform for the activation and functionalization of the highly thermodynamically stable C(sp3)−H and C−C bonds. Operating under simple “dump-and-stir” conditions at ambient temperature, the method employs low catalyst loadings to convert alkanes and aliphatic acids directly into high-value C−N, C−C, and C−S coupled products. Remarkably, the same system facilitates near-complete oxidative depolymerization of PS, predominantly yielding benzoic acid, which is a fundamental industrial building block. These findings unveil a previously unknown dimension of zirconium catalysts, significantly expanding the synthetic versatility of this overlooked metal.