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

含氮化学品，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、农用化学品和响应材料。含胺材料是高附加值产品，应用广泛，从二氧化碳捕集材料到抗微生物涂料。由于胺在有用的商业产品中的普遍存在，化学家们开发了许多方法来选择性地将氮安装到化合物中，其中许多方法会产生大量的废物。我的计划旨在为制造含有分子和材料的胺的化学工业开发可持续发展的技术。多年来，Schafer小组通过开发用于选择性、原子经济性合成胺的催化剂，推动了绿色化学的发展。此外，这个研究项目还使用了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了解启发了对醇的研究，而不是胺。酒精可以从生物质来源获得可再生资源，是将化学制造转变为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，以改善催化活性。N，O-螯合框架很容易修改，使得快速识别改进的甚至新的转化变得容易。本科生、研究生和博士后学员完成详细的结构、动力学和计算力学实验，以了解这些转变是如何发生的。这些见解指导了加强的催化剂开发工作，并导致了世界领先的烯烃与胺的氢化功能化反应，以及用于氢氨基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，我们已经证明了尿酸酯N，O-螯合的钽络合物通过广泛的胺和烯烃促进了这一反应，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替代的成键策略，以制备天然产物和药物分子中普遍存在的氨基酸和各种N-杂环。我们还建议制备新的胺功能化聚合物，将与学术和工业合作伙伴合作进行研究，用作防腐涂料、抗微生物添加剂和二氧化碳捕获材料。我们还试图通过在改进的McMurry偶联反应中使用醇偶联反应来开发能够产生氢化功能化反应所需的烯烃起始物质的催化剂。因此，这项提议旨在推动利用生物质衍生的可再生资源来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.