Ground State Generation and Cyclization of Aminium Radicals in the Formation of Tetrahydroquinolines

This paper reports the first examples of ground state radical-mediated intramolecular C-H amination to afford 1-methyl-1,2,3,4-tetrahydroquinolines from N-2,4-dinitrophenoxy derivatives of arylpropylamines. Whereas the photoactivation of N-2,4-dinitrophenoxyamines for intermolecular reactions has been established, ground state chemistry provides the desired cyclization products in moderate to excellent yields using Ru(bpy)(3)Cl-2 (42-95% yields) under acidic conditions under an air atmosphere.