To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed
为了改善获得关键合成中间体的途径,我们的目标是直接进行氢
溴化-根岸路线。毫不奇怪,在AIBN的存在下,将
溴化氢在马齿中添加反马尔可夫尼可夫成功。然而,即使在没有添加
引发剂的情况下,也观察到了反马尔科夫尼科夫的加入。对早期报道的重新检查表明,除非排除了空气,否则在
溴化氢中并不总是观察到选择性马尔科夫尼科夫加法,通常简称为“正常”加法,导致重新发现了可重现且可扩展的无
引发剂方案。