Photoinduced direct 4-pyridination of C(sp3)-H Bonds

Direct substitution of hydrogen in C(sp(3))-H bonds by 4-pyridine was achieved by employing benzophenone and 4-cyanopyridine in aqueous acetonitrile under photo-irradiating conditions. This simple and mild 4-pyridination proceeds in a highly chemoselective manner especially at benzylic C(sp(3))-H bonds without affecting polar functional groups, and enables intermolecular formation of sterically hindered bonds between alkylaromatics and 4-pyridine. The present methodology thus serves as a powerful tool for construction of biologically active and functional molecules with 4-pyridine substructures.