Department of Chemistry, Columbia University, New York, New York 10027, United States.
J Am Chem Soc. 2011 Feb 9;133(5):1260-2. doi: 10.1021/ja109617y. Epub 2011 Jan 4.
Tropylium ion mediated α-cyanation of amines is described. Even in the presence of KCN, tropylium ion is capable of oxidizing various amine substrates, and the resulting iminium ions undergo salt metathesis with cyanide ion to produce aminonitriles. The byproducts of this transformation are simply cycloheptatriene, a volatile hydrocarbon, and water-soluble potassium tetrafluoroborate. Thirteen total substrates are shown for the α-cyanation procedure, including a gram scale synthesis of 17β-cyanosparteine. In addition, a tropylium ion mediated oxidative aza-Cope rearrangement is demonstrated.
描述了三价锍离子介导的胺类α-氰化反应。即使有 KCN 存在，三价锍离子也能够氧化各种胺类底物，生成的亚胺离子与氰离子进行盐交换反应，生成氨基腈。这种转化的副产物仅是挥发性烃类环庚三烯和水溶性的四氟硼酸钾。该α-氰化方法共展示了 13 种底物，包括 17β-氰基沙普瑞林的克级规模合成。此外，还证明了三价锍离子介导的氧化氮杂 Cope 重排反应。
