Redox-Selective Iron Catalysis for alpha-Amino C-H Bond Functionalization via Aerobic Oxidation

摘要

Single-electron oxidation and a-deprotonation of tertiary anilines using Fe(phen)(3)(PF6)(3) afford alpha-aminoalkyl radicals, which can be coupled with electrophilic partners to afford various tetrahydroquinolines. Mechanistically, the Fe(phen)(n)(2+)(/3+) catalytic cycle is maintained by O-2 or a TBHP oxidant, and the presence of the oxygen bound iron complex, Fe(III)-OO(H), was elucidated by electron paramagnetic resonance and electrospray ionization mass spectrometry. This redox-selective nonheme iron catalyst behaves similarly to bioinspired heme iron catalysts.