Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Chem Asian J. 2012 Nov;7(11):2600-6. doi: 10.1002/asia.201200359. Epub 2012 Jul 4.
A copper-catalyzed migratory oxidative-coupling reaction between nitrones and various ethers/amines exhibited high functional-group tolerance. Even in aqueous media, the reaction proceeded efficiently. For practical use of this catalysis, a unique sequential Huisgen cycloaddition was demonstrated. Mechanistic investigations revealed that the reaction proceeded through oxidative catalytic activation of ethers/amines to afford iminium/oxonium intermediates by concurrent dual one-electron abstractions by copper(II) and oxyl radicals.
铜催化的硝酮与各种醚/胺之间的迁移氧化偶联反应表现出高的官能团容忍性。即使在水相介质中，反应也能高效进行。为了实际应用这种催化，我们还展示了独特的连续 Huisgen 环加成反应。通过机理研究揭示了反应经历了醚/胺的氧化催化活化，通过铜(II)和氧自由基的协同双重单电子转移，生成亚胺/氧鎓中间体。
