Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA.
J Am Chem Soc. 2010 Feb 10;132(5):1464-5. doi: 10.1021/ja909145y.
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.
我们报告了可见光光氧化还原催化在通过氧化氮杂 Henry 反应在叔 N-芳基胺和硝基烷烃之间形成 C-C 键中的应用。在 1 mol% Ir(ppy)(2)(dtbbpy)PF(6)的存在下，硝基烷烃与原位生成的亚胺离子的有效偶联以高达 96%的收率提供了所需的产物。机理研究表明，叔胺对 Ir(3+)激发态的还原猝灭导致铵自由基阳离子，随后可能通过大气氧实现催化剂的循环（Ir(2+)→Ir(3+)）。
