Youn So Won, Lee So Ra
Center for New Directions in Organic Synthesis, Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, Korea.
Org Biomol Chem. 2015 Apr 28;13(16):4652-6. doi: 10.1039/c5ob00361j.
Inspired by the Hegedus aza-Wacker indole synthesis, we were intrigued with the fate of the aminopalladation intermediate if syn β-hydrogen is made inaccessible or unavailable. In contrast to our previously reported β-carbon elimination, cyclization of a variety of 2-alkenylaniline substrates under electrophilic palladium conditions unexpectedly afforded C3-substituted indoles. This unusual 1,2-migratory process was found to be operative across a variety of substrates with predictable migratory aptitude. A mechanistic proposal was put forward to rationalize the observed substrate dependence, and this unexpected finding could provide an opportunity for other related processes.
受赫格杜斯氮杂-瓦克吲哚合成反应的启发，我们对如果顺式β-氢无法接近或不存在时氨基钯化中间体的命运产生了兴趣。与我们之前报道的β-碳消除反应不同，在亲电钯条件下，各种2-烯基苯胺底物的环化意外地得到了C3-取代的吲哚。发现这种不寻常的1,2-迁移过程在各种具有可预测迁移能力的底物中都能发生。提出了一个机理来解释观察到的底物依赖性，这一意外发现可能为其他相关过程提供机会。
