Copper(I)-Catalyzed Amide Oxazoline-Directed, Atom-Economic C–H Selenylation of (Hetero)Arenes under External Oxidant-Free Conditions

We report the first Cu(I)-catalyzed amide oxazoline-directed C-H selenylation of arenes and heteroarenes under external oxidant-free conditions with high atom economy. This newly developed method delivers the desired novel C-H selenylated products in good to outstanding yields, exhibiting a broad substrate scope and excellent tolerance toward various functional groups, including heterocycles. The methodology has been successfully extended to C-H thiolation and telluration reactions. Notably, the protocol has been employed for gram-scale synthesis and further product derivatization, highlighting its synthetic utility. The process offers high atom economy, and the directing group can be conveniently removed from the product. Comprehensive mechanistic insights were gained through control experiments and spectroscopic techniques to elucidate the catalytic cycle. Additionally, the photoluminescence study of a representative product (4a) was studied, revealing strong fluorescence. Selected synthesized novel compounds were also evaluated for their biological activity, showing promising antibacterial and anticancer effects in vitro.