Herein, we report a photouranium-catalyzed aerobic C-N bond coupling strategy for the synthesis of hemiaminal ether derivatives. This method offers a potential alternative to conventional protocols that typically require stoichiometric oxidants. The uranium catalyst plays a dual role: it acts as a photocatalyst to activate the ether C-H bond under light irradiation and serves as a Lewis acid to facilitate the coupling of the resulting intermediate with N-heterocycles. A wide range of ethers and N-heterocycles are compatible, affording the corresponding products in up to 99% yield, using air as the sole oxidant. Moreover, a possible photoinduced hydrogen abstract pathway of the uranium-ether complex was proposed via detailed spectrum analysis and density functional theory (DFT) calculations, different from traditional intermolecular hydrogen atom transfer (HAT) between the reactant and excited catalyst. At last, a further light/thermal sequence was established, allowing light-sensitive pharmaceuticals and functionalized materials to convert into target compounds smoothly.
Zhang et al. (Thu,) studied this question.