Photochemical and Photocatalytic Amination Reactions with Monovalent Nitrogen-based Reactive Intermediates

与一价氮基反应中间体的光化学和光催化胺化反应

• 批准号: 515365930
• 负责人: Professor Dr. Rene M. Koenigs
• 金额: --
• 依托单位: Institut für Organische Chemie (IOC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/515365930?language=en
• 关键词: Photochemical; Photocatalytic; Amination; Reactions; Monovalent

The amination represents one of the most important reactions in organic synthesis and is widely used in drug discovery or material sciences. Typically, aminations are realized via classic substitution reactions or via metal-catalyzed coupling reactions. An alternative lies within amination reactions using nitrene intermediates. However, such amination reactions are even today severely limited and often require forcing reaction conditions, since basic amines can easily inhibit the Lewis acidic transition metal catalysts. Under photochemical or photocatalytic conditions however, a free nitrene or a free nitrene radical anion can be generated, thereby overcoming classic limitations of nitrene transfer reactions. So far such photochemical or photocatalytic nitrene transfer reactions have only been used sporadically in organic synthesis, and current work is mainly limited to the use of high-energy UV light. The use of visible light has only been described in a few selected cases. Building on our work on photochemical and photocatalytic nitrene transfer reactions, we now want to examine these in detail here. The understanding of reactivity and identification of suitable new reagents plays a central role in enabling such nitrene transfer reactions and is therefore an important task in the development of sustainable synthetic methods and in understanding this conceptual approach in organic synthesis. In a first part, the planned work focuses on photochemical and photocatalytic amination reactions of poly-unsaturated hydrocarbons as well as C-H amination reactions with iodinanes to gain an understanding of the reactivity of free nitrenes. Further work focuses on expanding the range of applications with regard to the aminating reagent. Different amination reagents will be systematically investigated and applied in amination reactions. All planned studies include detailed mechanistic experiments, such as absorption spectroscopy, fluorescence quenching, or cyclic voltammetry, as well as DFT calculations to support the experimental data and elucidate reaction mechanisms.

胺化是有机合成中最重要的反应之一，广泛用于药物发现或物质科学中。通常，通过经典的替代反应或金属催化的耦合反应来实现障碍。另一种替代性在于使用硝酸中间体的胺化反应。但是，这种氨化反应即使在今天也受到严重限制，并且通常需要迫使反应条件，因为碱性胺可以很容易地抑制刘易斯酸性过渡金属催化剂。但是，在光化学或光催化条件下，可以产生游离硝酸盐或游离硝基自由基阴离子，从而克服硝酸烯转移反应的经典局限性。到目前为止，此类光化学或光催化硝基转移反应仅在有机合成中偶发地使用，并且当前的工作主要限于使用高能紫外线。可见光的使用仅在一些选定的情况下被描述。基于我们在光化学和光催化硝酸转移反应的工作，我们现在想在此处详细研究这些反应。对反应性和对合适新试剂的识别的理解在实现这种硝基转移反应方面起着核心作用，因此是发展可持续合成方法的重要任务，并在理解有机合成中的这种概念方法方面起着重要的作用。在第一部分中，计划的工作集中于多饱和烃的光化学和光催化胺化反应以及与碘的C-H胺化反应，以了解自由硝酸盐的反应性。进一步的工作着重于扩大有关胺化试剂的应用范围。不同的胺化试剂将在胺化反应中系统地研究和应用。所有计划的研究包括详细的机理实验，例如吸收光谱，荧光淬火或环状伏安法，以及DFT计算，以支持实验数据和阐明反应机制。