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。这样就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，它们分别参与路易斯酸催化的转移氢化硅烷化和烯烃的氢化。实现转移氢卤化的相关无机酸替代物是非常理想的，但化学性质不稳定，通常会在芳构化的同时快速消除 HX。我们现在设计了一种新型转移试剂，同样基于环己-1,4-二烯平台，该试剂具有化学稳定性，从而可以控制 HX 的释放以及将 HX 转移到碳-碳多重键上。该过程是质子催化的，因此与早期的无过渡金属转移反应不同。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，并将其应用于转移氢卤化。还预计该策略将扩展到转移硅烷基卤化。