Palladium(II)-Catalyzed Regioselective C(sp3)-H Selenylation of 8-Methylquinoline Derivatives.

We report the first ligand-free palladium(II)-catalyzed regioselective C(sp3)-H selenylation of 8-methylquinoline derivatives using aryl selenenyl chlorides as the selenating reagents. The reaction proceeds smoothly over a broad range of substrates with excellent regioselectivity, affording the corresponding selenium-containing quinoline derivatives in good to high yields. The protocol does not require external ligands, is amenable to scale-up, and tolerates a wide variety of functional groups. Preliminary synthetic applications demonstrate the potential utility of this method in medicinal chemistry.