An Electrochemical Approach to Amine Synthesis from Nitrogen

项目总结/摘要 含氮官能团构成健康相关小分子中最大的类别之一。 因此，开发构建碳-氮键的新方法仍然是最重要的。 化学合成的创新机会。哈伯-博施过程可以说是最重要的 一种合成催化方法，其中通过铁催化剂将大气氮（N2）还原成氨（NH3 在高温高压下相比之下，自然界的N2固定催化剂，固氮酶，在环境温度下工作。 条件下使用的活性位点。因此，许多定义明确的配位络合物已经被 开发用于研究N2还原中的关键键形成步骤，目的是设计更有效的催化剂， 氨和其他增值化合物的合成。虽然在催化方面取得了一些成功， N2甲硅烷基化以得到三（三烷基甲硅烷基）胺，没有用于胺的类似催化方法的实例 通过由N2形成碳-氮键来合成。N2直接转化的当前策略 胺需要金属-N2络合物与有机亲电试剂的多步合成序列， 在苛刻条件下释放产品。为了规避这些限制，拟议的研究采用 促进用于自由基官能化的质子偶联电子转移途径的基于二苯乙烯的催化剂 金属-N2催化剂通过有机激进一代的复兴，可以轻松获得一套丰富的 烯烃，并通过利用金属-N2催化剂的互补反应性模式， 可以合成仲胺和芳基胺产物。研究计划概述了具体的方法， 将提供对金属-N2络合物与有机自由基和金属氮化物反应的基本见解， 在N2还原中通常提出的中间体，与烯烃。这些研究将为 实现从最丰富的来源催化合成医学相关的官能团， 氮气N2

Project Summary/Abstract Nitrogen-containing functionalities constitute one of the largest classes within health-relevant small molecules. Therefore, the development of new methods to construct carbon–nitrogen bonds remains paramount among opportunities for innovation in chemical synthesis. The Haber–Bosch process is arguably the most important synthetic catalytic process, wherein atmospheric nitrogen (N2) is reduced to ammonia (NH3) by an iron catalyst under high temperature and pressure. In contrast, nature’s N2 fixation catalysts, nitrogenases, operate at ambient conditions using a bimetallic active site. As such, many well-defined coordination complexes have been developed to study key bond-forming steps in N2 reduction, with the goal of designing more efficient catalysts for the synthesis of ammonia and other value-added compounds. While there has been some success in catalytic N2 silylation to give tris(trialkylsilyl)amines, there are no examples of the analogous catalytic process for amine synthesis through carbon–nitrogen bond-formation from N2. Current strategies for the direct conversion of N2 amines require multistep synthetic sequences of metal–N2 complexes with organic electrophiles and subsequent product release under harsh conditions. To circumvent these limitations, the proposed research employs metallocene-based catalysts to promote proton-coupled electron-transfer pathways for radical functionalization of metal–N2 catalysts. Enabled by a renaissance in organic radical generation, easy access to a suite of abundant olefins, and by exploiting complementary reactivity modes of metal–N2 catalysts, a diverse range of primary, secondary, and aryl amine products can be synthesized. The research plan outlines specific approaches that will deliver fundamental insights into reactions of metal–N2 complexes with organic radicals and metal nitrides, commonly proposed intermediates in N2 reduction, with alkenes. These studies will provide the foundation for the realization of a catalytic synthesis of medicinally relevant functional groups from the most abundant source of nitrogen—N2.