Transition-Metal-Free Transfer Hydrohalogenation

无过渡金属转移氢卤化

• 批准号: 405628012
• 负责人: Professor Dr. Martin Oestreich
• 金额: --
• 依托单位: Institut für Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405628012?language=en
• 关键词: Transition; Metal; Free; Transfer; Hydrohalogenation

The transfer of small molecules from one molecule to another recently turned into an emerging area. By this, the handling of gaseous and potentially dangerous chemicals is bypassed. Our laboratory introduced adequately substituted cyclohexa-1,4-dienes as surrogates of hydrosilanes and dihydrogen, and these engage in Lewis acid-catalyzed transfer hydrosilylation and hydrogenation of alkenes, respectively. Related surrogates of mineral acids to achieve transfer hydrohalogenation are highly desirable but not chemically stable, usually rapidly eliminating HX concomitant with aromatization. We have now designed a new type of transfer reagent, again based on the cyclohexa-1,4-diene platform, that is chemically robust, thereby allowing for controlled release of HX as well as transfer of HX onto carbon-carbon multiple bonds. The process is proton-catalyzed and, as such, different from the earlier transition-metal-free transfer reactions. Within this project, we will develop synthetically useful low-molecular-weight surrogates, predominantly for X = I, Br, Cl and even F, and apply these to transfer hydrohalogenation. Expansion of this strategy to transfer silylhalogenation is also anticipated.

小分子从一个分子到另一个分子的转移最近成为一个新兴领域。这样，绕过了气态和潜在危险化学品的处理。我们的实验室引入了充分取代的环己-1，4-二烯作为氢硅烷和二氢的替代物，它们分别参与刘易斯酸催化的转移硅氢加成和烯烃的氢化。实现转移氢卤化的无机酸的相关替代物是高度期望的，但不是化学稳定的，通常伴随芳构化快速消除HX。我们现在已经设计了一种新型的转移试剂，再次基于环己-1，4-二烯平台，其具有化学稳定性，从而允许HX的受控释放以及HX转移到碳-碳多重键上。该过程是质子催化的，因此不同于早期的无过渡金属转移反应。在这个项目中，我们将开发合成有用的低分子量替代物，主要是X = I，Br，Cl甚至F，并将其应用于氢卤化转移。还预期将该策略扩展到转移甲硅烷基卤化。