Ferreira Eric M, Stoltz Brian M
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
J Am Chem Soc. 2003 Aug 13;125(32):9578-9. doi: 10.1021/ja035054y.
A palladium-catalyzed aerobic oxidative annulation of indoles is described. We have demonstrated that a variety of factors influence these cyclizations, and in particular the electronic nature of the pyridine ligand is crucial. It is also remarkable that these oxidative cyclizations can proceed in good yield despite background oxidative decomposition pathways, testament to the facile nature with which molecular oxygen can serve as the direct oxidant for Pd(0). We have also shown that the mechanism most likely involves initial indole palladation (formal C-H bond activation) followed by migratory insertion and beta-hydrogen elimination.
本文描述了一种钯催化的吲哚需氧氧化环化反应。我们已经证明，多种因素会影响这些环化反应，特别是吡啶配体的电子性质至关重要。同样值得注意的是，尽管存在背景氧化分解途径，但这些氧化环化反应仍能以良好的产率进行，这证明了分子氧作为Pd(0)直接氧化剂的便捷性。我们还表明，其反应机理最有可能涉及最初的吲哚钯化（形式上的C-H键活化），随后是迁移插入和β-氢消除。
