Palladium-catalyzed alkene carboamination reactions for the synthesis of substituted piperazines
作者:Josephine S. Nakhla、Danielle M. Schultz、John P. Wolfe
DOI:10.1016/j.tet.2009.04.017
日期:2009.8
piperazines from amino acid precursors is described. The target compounds are generated in 95–99% ee with good to excellent levels of diastereoselectivity (usually 14:1 to >20:1) using Pd-catalyzed carboamination reactions between aryl or alkenyl halides and substituted ethylenediamine derivatives to form the heterocyclic rings. The synthesis requires only 4–5 steps from commercially available amino acids, and
描述了从氨基酸前体立体选择性制备对映体富集的顺式-2,6-二取代哌嗪的策略。使用 Pd 催化芳基或烯基卤化物与取代乙二胺衍生物之间的碳胺化反应形成杂环,以 95-99% ee 生成目标化合物,具有良好至极好的非对映选择性(通常为 14:1 至 >20:1)。合成仅需 4-5 步即可从市售氨基酸中提取,并允许模块化构建在 N 1、N 4、C 2和 C 6处具有不同取代基的哌嗪. 还报道了使用这种策略构建 2,3-二取代哌嗪、稠合双环哌嗪和四氢喹喔啉。此外,讨论了关键的碳胺化反应的机理,并提出了预测和解释这些转化立体化学结果的新模型。