AbstractAlkyne hydroamination is an effective approach for the production of enamines and enamine‐containing N‐heterocycles. However, stereoselectivity control is a considerable challenge in this reaction because of the electronic repulsion between an incoming nitrogen lone pair and the alkyne π‐system. Herein, we propose a methodology involving β‐regio‐ and Z‐selective alkyne hydroamination by using tetrafluoro‐λ6‐sulfanyl (SF4) alkynes under superbasic, naked anion conditions. The reaction is compatible with a wide variety of N‐heterocycles, including indoles, carbazoles, pyrazoles, and imidazoles, and selectively furnishes SF4‐linked Z‐vinyl enamines with β‐regioselectively. Moreover, the method can be extended to the β‐ and Z‐controlled, base‐mediated alkyne hydrophenoxylation with phenols to provide SF4‐linked Z‐vinyl ethers in high yields. As the SF4 unit has attracted attention as a bioisostere for alkynes, p‐benzenes, bicyclo[1.1.1]pentyl (BCP) groups, and cubanes in medicinal chemistry, this chemistry represents an effective approach to creating novel drug candidates incorporating SF4‐containing molecules.
摘要
炔烃氢化反应是生产
烯胺和含
烯胺的 N-杂环的有效方法。然而,由于进入的
氮孤对与
炔烃 π-系统之间存在电子排斥,立体选择性控制在该反应中是一个相当大的挑战。在此,我们提出了一种方法,即在超碱性裸阴离子条件下,使用四
氟-λ6-
硫代(SF4)
炔烃,进行 β-regio- 和 Z-选择性
炔烃氢化反应。该反应与包括
吲哚、
咔唑、
吡唑和
咪唑在内的多种 N-
杂环化合物兼容,并能以β-区选择性地生成与 SF4 链接的 Z-
乙烯基烯胺。此外,该方法还可扩展到β和Z控制的、碱介导的
炔烃与
酚的
水合苯氧基化反应,从而以高产率提供 SF4 链接的 Z-
乙烯基醚。在药物
化学中,SF4 单元作为
炔烃、对
苯类、双环[1.1.1]戊基 (
BCP) 基团和
立方烷的
生物异构体已经引起了人们的关注,因此这种
化学方法是创造含有 SF4 分子的新型候选药物的有效途径。