화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.136, No.35, 12217-12220, 2014
Catalytic Olefin Hydroamination with Aminium Radical Cations: A Photoredox Method for Direct C-N Bond Formation
While olefin amination with aminium radical cations is a classical method for C-N bond formation, catalytic variants that utilize simple 2 degrees amine precursors remain largely undeveloped. Herein we report a new visible-light photoredox protocol for the intramolecular anti-Markovnikov hydroamination of aryl olefins that proceeds through catalytically generated aminium radical intermediates. Mechanistic studies are consistent with a process involving amine oxidation via electron transfer, turnover-limiting C-N bond formation, and a second electron transfer step to reduce a carbon-centered radical, rendering the overall process redox-neutral. A range of structurally diverse N-aryl heterocycles can be prepared in good to excellent yields under conditions significantly milder than those required by conventional aminium-based protocols.