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.

胺化反应是有机合成中最重要的反应之一，广泛应用于药物发现和材料科学。通常，胺化通过经典的取代反应或通过金属催化的偶联反应实现。另一种选择是使用氮烯中间体的胺化反应。然而，这种胺化反应即使在今天也受到严重限制，并且经常需要强制反应条件，因为碱性胺可以容易地抑制刘易斯酸性过渡金属催化剂。然而，在光化学或光催化条件下，可以产生游离氮烯或游离氮烯自由基阴离子，从而克服氮烯转移反应的经典限制。到目前为止，这种光化学或光催化氮烯转移反应只是零星地用于有机合成，目前的工作主要限于使用高能紫外光。可见光的使用仅在少数选定的情况下进行了描述。基于我们在光化学和光催化氮烯转移反应方面的工作，我们现在想在这里详细研究这些反应。反应性的理解和识别合适的新试剂在实现这样的氮烯转移反应中起着核心作用，因此在可持续的合成方法的发展和理解有机合成中的这种概念方法中是一项重要任务。在第一部分中，计划的工作集中在多不饱和烃的光化学和光催化胺化反应以及与碘烷的C-H胺化反应，以了解游离氮烯的反应性。进一步的工作集中在扩大胺化试剂的应用范围。对不同的胺化试剂进行了系统的研究和应用。所有计划的研究包括详细的机理实验，如吸收光谱，荧光猝灭，或循环伏安法，以及DFT计算，以支持实验数据和阐明反应机理。