Manganese complex catalysts for hydrogenation and dehydrogenation reactions

可持续地处理我们星球上的资源是人类面临的一项核心挑战。贵金属稀有，价格昂贵，在关键技术中的用途多种多样。催化就是这样一项关键技术。锰是地壳中第三丰富的过渡金属，在加氢和脱氢反应中有望取代贵金属催化剂。如果有新的反应性或选择性，这样的“替代”就变得特别有趣。在最近(2016和17)发表在Angewandte Chemie上的三篇前期工作手稿中，我们介绍了用于重要加氢和脱氢反应的新型高活性锰催化剂。我们把重点放在提案的三个目标上。1.对PNP配体稳定的锰络合物在加氢或脱氢反应中的作用有了更好的了解，并由此衍生出新的催化应用。2.基于(手性)PNN-钳形配体的新型锰催化剂的开发。3.新的锰催化反应的发展，在该反应中，氨基醇被转化为重要的化合物。1.加氢和脱氢催化机理研究：在前期工作中，我们可以发现在C=O键的加氢反应中，锰催化剂是一种有趣的替代贵金属催化剂。化学。2016年，论文1)。目前，我们不知道催化循环是如何进行的，底物的激活是如何发生的。因此，我们建议进行机理研究，这样也可以进行更合理的催化剂设计。所获得的洞察力应用于亚胺在氢化敏感官能团存在下的氢化。除了氢化作用，我们还对脱氢反应的机械方面感兴趣，特别是碱基的作用。新型(手性)催化剂：锰基加氢和脱氢催化剂的进展与新型催化剂的开发密切相关。因此，我们计划开发一种新型的(也是手性的)催化剂。因此，应用了一种简单且可变的配体合成方法。这种新型催化剂被用于各种反应的比较中。例如，在对映体选择性催化方面，亚胺的氢化是很有意义的。3.新的醇重功能化反应：在我们的初步工作中，我们可以在脱氢缩合反应中展示一个类似的Mn-Ir反应来合成芳香族N-杂环化合物(2×angew)。化学。2017年，第2和3号文件)。因此，利用锰催化剂合成杂环化合物的新方法在未来应该是可能的。除了碱基可调的亚胺-胺合成外，还提出了一种新型的嘧啶和咪唑的合成方法。前期工作支持了它们的可行性。

The sustainable handling of the resources on our planet is a central challenge of humankind. Noble metals are rare, expensive and are used diversely in key technologies. Catalysis is such a key technology. Manganese is the third most abundant transition metal in the earth’s crust and a promising “replacement” for noble metal catalysts in hydrogenation and dehydrogenation reactions. Such a “replacement” becomes especially interesting if new reactivity or selectivity are accessible. In three recent (2016 and 17) preliminary work manuscripts published in Angewandte Chemie, we introduced novel highly active manganese catalysts for important hydrogenation and dehydrogenation reactions. We focus on three aims in the proposal. 1. A better understanding of how PNP-ligand stabilized manganese complexes act in hydrogenation or dehydrogenation reactions and thereof derived novel catalytic applications. 2. The development of novel manganese catalysts based on (chiral) PNN-pincer ligands. 3. The development of novel Mn-catalyzed reactions in which amino alcohols are converted into important classes of compounds. 1. Mechanistic studies of hydrogenation and dehydrogenation catalysis: In the preliminary work, we could show that manganese catalysts are an interesting alternative to noble metal catalysts in the hydrogenation of C=O bonds (Angew. Chem. 2016, paper 1). Right now we don’t know how the catalytic cycle proceeds and how the activation of substrates takes place. We thus propose mechanistic studies, which also permit a more rational catalyst design. The obtained insight should be used for the hydrogenation of imines in the presence of hydrogenation sensitive functional groups. Beside hydrogenation we are interested in mechanistic aspects of the dehydrogenation, especially the role of the base.2. Novel (chiral) catalysts: Progress in manganese based hydrogenation and dehydrogenation catalysis is strongly linked with the development of novel catalysts. Thus, we plan the development of a novel (also chiral) catalyst class. Therefore, a simple and broadly variable ligand synthesis is applied. The novel catalysts are used comparative in a variety of reactions. With regard to enantioselective catalysis, for instance, the hydrogenation of imines is of interest. 3. Novel alcohol re-functionalization reactions: In our preliminary work, we could demonstrate a Mn-Ir analogy in dehydrogenative condensation reaction for the synthesis of aromatic N-heterocyclic compounds (2 x Angew. Chem. 2017, paper 2 and 3). Thus, the development of novel syntheses of heterocycles using manganese catalysts should be possible in the future. Beside the base-tunable Imine-amine synthesis, the development of a novel pyrimidine and imidazole synthesis is proposed. Preliminary work support the feasibility of them.