TEMPO as Hydrogen\nAtom Transfer Catalyst in Enhancing\nIminyl Radical Cyclization of <i>O</i>‑Acetyl Oxime\ntoward Phenanthridines and Isoquinolines

Herein, we present a strategy for\npromoting the cyclization\nof <i>ortho</i>-aryl or <i>ortho</i> alkenyl arylketone\noxime ethers C–N bonds using TEMPO as a direct hydrogen atom\ntransfer (HAT) catalyst. The reaction employs a green solvent and\nrequires no introduction of metal additives. It only needs catalytic\namount of TEMPO to drive the reaction. Gram-scale reaction yields\nthe corresponding products with satisfactory yields, providing a novel\nand efficient method for the synthesis of phenanthridine and isoquinoline\nderivatives.