Green Chemistry using Early Transition Metal Catalysts for the Synthesis of Small Molecules and Materials

含氮化学物质，胺，是生物组装的关键成分，如蛋白质和DNA，以及合成产品，如药品，农用化学品和反应材料。含胺材料是具有多种应用的高价值产品，从二氧化碳捕获材料到抗菌涂层。由于有用的商业产品中普遍存在胺，化学家们已经开发出许多方法来选择性地将氮安装到化合物中，其中许多方法产生了大量的浪费。我的项目旨在为制造含胺分子和材料的化学工业开发可持续技术。多年来，Schafer团队通过开发用于选择性、原子经济合成胺的催化剂，推动了绿色化学的发展。此外，该研究项目的特点是使用了3d早期过渡金属钛和钒，这些金属储量丰富，成本低，毒性低。我们对这些催化剂的理解激发了对醇的研究，而不是对胺的研究。醇可以从生物质资源中再生获得，并且是将化学制造业过渡到循环经济的关键组成部分。我们的研究项目率先开发了一类以N， o螯合配体为关键成分的催化剂，以修饰催化活性。N， o螯合框架很容易修改，因此可以很容易地快速识别改进的甚至是新的转换。本科生、研究生和博士后水平的受训者完成详细的结构、动力学和计算机制实验，以了解这些转变是如何发生的。这些见解指导了催化剂的开发工作，并导致了世界领先的炔与胺的加氢功能化反应，以及通过加氢胺烷基化直接催化烯烃胺化的广泛有用的催化剂。在过去的六年里，我们已经证明了钽的脲酸盐N， o螯合配合物促进了与广泛的胺和烯烃的反应，我们已经学会了如何控制这些转化的区域选择性和非对映选择性。在这里，我们建议将这些催化剂的钛变体应用于制备氨基酸和天然产物和药物分子中普遍存在的各种n -杂环的替代键制策略。我们还建议与学术和工业伙伴合作，研究制备新的胺功能化聚合物，用于防腐涂层，抗菌添加剂和二氧化碳捕获材料。我们还寻求开发催化剂，通过在修饰的McMurry偶联中使用醇偶联反应，可以生成我们需要用于加氢官能化反应的烯烃起始材料。因此，本提案旨在推动利用生物质衍生的可再生资源合成高价值的小分子胺和材料。

Nitrogen containing chemicals, amines, are key components of biological assemblies, like proteins and DNA, as well as synthetic products such as pharmaceuticals, agrochemicals and responsive materials. Amine containing materials are high-value products that have diverse applications ranging from CO2 capture materials to anti-microbial coatings. Due to the prevalence of amines in useful commercial products, chemists have developed many ways to selectively install nitrogen into compounds, many of which generate significant waste. My program aims to develop sustainable technologies for chemical industries that make amine containing molecules and materials. Over the years the Schafer group has advanced green chemistry by developing catalysts for the selective, atom-economic synthesis of amines. Also, this research program features the use of 3d early transition metals, titanium and vanadium, which are abundant, of low cost and low toxicity.  Our understanding of these catalysts have inspired investigations with alcohols, rather than amines. Alcohols can be renewably obtained from biomass sources and are key building blocks for transitioning chemical manufacturing into the circular economy. Our research program has pioneered the development of a class of catalysts that feature N,O-chelating ligands as key components to modify catalytic activity. The N,O-chelating framework is easily modified, making it simple to rapidly identify improved or even new transformations. Trainees at the undergraduate, graduate and postdoctoral levels complete detailed structural, kinetic and computational mechanistic experiments to understand how these transformations occur. These insights guide enhanced catalyst development efforts and have resulted in world-leading hydrofunctionalization reactions of alkynes with amines and broadly useful catalysts for the direct, catalytic amination of alkenes by hydroaminoalkylation. Over the past six years we have shown that ureate N,O-chelated complexes of tantalum promote this reaction with a broad range of amines and alkenes and we have learned how to control both the regio- and diastereoselectivity of these transformations. Here we propose to apply titanium variants of these catalysts in alternative bond-making strategies for preparing amino acids and a variety of N-heterocycles that are prevalent in natural products and drug molecules. We also propose to prepare new amine functionalized polymers that will be investigated, in collaboration with academic and industrial partners, for use as anti-corrosion coatings, anti-microbial additives, and CO2 capture materials. We also seek to develop catalysts that can generate the alkene starting materials that we need for hydrofunctionalization reactions, by using alcohol coupling reactions in a modified McMurry coupling. Thus, this proposal aims to push toward using biomass derived, renewable resources for the synthesis of high-value small molecule amines and materials.