Birch reactions employing alkali metals in ammonia have been a well‐established method for the reduction and functionalisation of aromatic compounds for nearly 100 years. Speculations regarding intermediates in the reaction pathway have been discussed since the beginning. We hereby report the isolation of NMe4(HNaph) (1), a kinetically trapped intermediate of the Birch reaction of naphthalene and sodium in liquid ammonia. 1 has been fully characterised and has been shown to continue to react to 1,2/1,4‐dihydronaphthalene – the Birch product of the reduction of naphthalene. The reactivity of 1 was investigated towards activity as an electron and hydride transfer agent with both, elements and small organic molecules. 1 demonstrates a tamed reduction potential which allows for controlled reactions such as the selective formation of hexasulphide and hexaselenide anions.

中文翻译：

---

氢萘单阴离子：从液氨中分离“红色瞬变”桦木中间体


近 100 年来，利用氨中碱金属的 Birch 反应一直是芳香族化合物还原和官能化的成熟方法。关于反应途径中中间体的推测从一开始就一直在讨论。我们在此报告了 NMe4(HNaph) (1) 的分离，它是萘和钠在液氨中发生 Birch 反应的动力学捕获中间体。 1 已得到充分表征，并已被证明可以继续反应生成 1,2/1,4-二氢萘——萘还原的 Birch 产物。研究了 1 作为电子和氢化物转移剂与元素和有机小分子的反应活性。图1展示了驯服的还原电位，其允许受控反应，例如选择性形成六硫化物和六硒化物阴离子。