Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
Langmuir. 2017 Jan 31;33(4):954-958. doi: 10.1021/acs.langmuir.6b04152. Epub 2017 Jan 20.
Halogenated organic compounds are important anthropogenic chemicals widely used in chemical industry, biology, and pharmacology; however, the persistence and inertness of organic halides cause human health problems and considerable environmental pollution. Thus, the elimination or replacement of halogen atoms with organic halides has been considered a central task in synthetic chemistry. In dehalogenation reactions, the consecutive single-electron transfer from reducing agents generates the radical and corresponding carbanion and thus removes the halogen atom as the leaving group. Herein, we report a new strategy for an efficient chemoselective hydrodehalogenation through the formation of stable carbanion intermediates, which are simply achieved by using highly mobile two-dimensional electrons of inorganic electride [CaN]·e with effective electron transfer ability. The consecutive single-electron transfer from inorganic electride [CaN]·e stabilized free carbanions, which is a key step in achieving the selective reaction. Furthermore, a determinant more important than leaving group ability is the stability control of free carbanions according to the s character determined by the backbone structure. We anticipate that this approach may provide new insight into selective chemical formation, including hydrodehalogenation.
卤代有机化合物是一种重要的人为化学物质,广泛应用于化学工业、生物学和药理学中;然而,有机卤化物的持久性和惰性会导致人类健康问题和严重的环境污染。因此,用有机卤化物取代或消除卤原子已被认为是合成化学中的一项核心任务。在脱卤反应中,还原剂连续的单电子转移会产生自由基和相应的碳负离子,从而将卤原子作为离去基团去除。在此,我们报告了一种通过形成稳定的碳负离子中间体来高效选择性氢化脱卤的新策略,该策略通过使用具有有效电子转移能力的高迁移二维电子无机电负性[CaN]·e 来简单地实现。无机电负性[CaN]·e 从稳定的自由碳负离子中连续转移单电子,这是实现选择性反应的关键步骤。此外,根据骨架结构确定的 s 特征,决定自由碳负离子稳定性的因素比离去基团能力更为重要。我们预计,这种方法可能为选择性化学形成提供新的见解,包括氢化脱卤。