New Ligand Designs for Homogeneous Catalytic Nitrogen Fixation

化学中尚未解决的挑战之一是发现一种有效而温和的过程，将分子氮(N2)转化为价值更高的有机氮物种，如胺或含氮杂环。众所周知，通过Haber-Bosch工艺生产氨已有100多年的历史，*并且仍然是唯一一种工业规模使用氮气作为原料的工艺。相比之下，等电子CO分子被用于各种不同的工业过程，如氢甲酰化、醋酸合成和羰化。即使在100多年后，仍然没有新的工业过程使用分子氮作为原料，这一事实提醒人们，在工业环境中使用这种非活性小分子的问题是困难的。这项提议旨在发现和优化将分子氮转化为更高价值有机材料的催化反应。我们在近三十年的时间里对氮素(N2)的化学计量激活做出了开创性的贡献。然而，最近，我们发现了一种独特的催化系统，它可以非常高效地将氮气转化为N(SiMe3)3，其成交量可以与世界上其他研究人员的最好报告相媲美。在这一令人兴奋的结果的基础上构建，是本次探索奖助金申请中提出的想法的重点。我们不仅希望通过研究新的配体设计和新的贱金属组合来优化这一过程，而且我们还希望通过上述N(SiMe3)3催化形成的机理研究来扩大这一反应以催化生成氮-碳键。该项目的成功将通过在高影响力的期刊上发表文章和继续培训高素质的人员来完成，这些人员将准备好解决具有社会重要性的重要化学问题。

One of the unmet challenges in chemistry is the*discovery of an efficient yet mild process for the conversion of molecular*nitrogen (N2) into higher value organo-nitrogen containing species,*such as amines or nitrogen-containing heterocycles. The well-known production of ammonia via the Haber-Bosch process is over 100 years old,*and is still the only process that uses N2 as a feedstock on an*industrial scale. In*contrast, the isoelectronic CO molecule is used in a variety of different*industrial processes, such as hydroformylation, the acetic acid synthesis, and*carbonylation. The fact*that even after more than 100 years there is still no new industrial process that*uses molecular nitrogen as a feedstock is a reminder of the difficulty of*the problem of using this unreactive small molecule in an industrial setting.****** This proposal seeks to both discover and optimize catalytic reactions that convert molecular nitrogen into higher-value organic materials. We have made seminal contributions to stoichiometric activation of dinitrogen (N2) that have spanned almost three decades. However, recently, we have discovered a unique catalytic system that very efficiently converts N2 into N(SiMe3)3 with turnover numbers that rival the best reports from other researchers world-wide. Building on this exciting result is the focus of the ideas presented in this Discovery Grant application. Not only do we want to optimize this process by examining new ligand designs and new base metal combinations, but we also want to expand this reaction to generate nitrogen-carbon bonds catalytically by building on mechanistic studies of the aforementioned catalytic formation of N(SiMe3)3. Success in this project will be in the form of publications in high-impact journals and the continued training of highly qualified personnel who will be ready to tackle important chemical problems of societal importance.