Visible-Light Photoredox Catalysis: Aza-Henry Reactions via C−H Functionalization

✍ Scribed by Condie, Allison G.; González-Gómez, José C.; Stephenson, Corey R. J.

• Book ID: 120275796
• Publisher: American Chemical Society
• Year: 2010
• Tongue: English
• Weight: 232 KB
• Volume: 132
• Category: Article
• ISSN: 0002-7863
• DOI: 10.1021/ja909145y

✦ Synopsis

We report the application of visible-light photoredox catalysis for the formation of C-C bonds between tertiary N-arylamines and nitroalkanes via an oxidative aza-Henry reaction. In the presence of 1 mol % Ir(ppy)(2)(dtbbpy)PF(6), efficient coupling of nitroalkanes with in situ-generated iminium ions provides the desired products in up to 96% yield. Mechanistic studies suggest that reductive quenching of the Ir(3+) excited state by the tertiary amine leads to the ammonium radical cation, with subsequent catalyst turnover (Ir(2+) --> Ir(3+)) likely effected by atmospheric oxygen.