CAS: Catalytic Reactions Using Multinuclear Complexes

在化学系化学催化项目的支持下，普渡大学的Christopher Uyeda教授正在研究活性部位含有多种金属的催化剂。许多用于医学、农业和聚合物化学的化合物具有复杂的结构，需要漫长的合成过程。催化剂开发在提高这些工艺的效率和可持续性方面发挥着关键作用，通过减少所需的合成转化次数，通过允许使用更容易丰富的起始材料，并通过最大限度地减少废弃副产物的产生。目前化学工业中使用的许多催化剂在其活性部位仅含有一种金属。相比之下，许多进行挑战性反应的酶在其活性位点含有多种金属的簇。Uyeda博士的研究小组从生物学中获得灵感，正在设计支持多种金属在其活性部位存在的配体，并使用它们进行许多有机转化。由于高中，本科，研究生和博士后研究人员的多元化群体参与了这个项目，这项工作也有助于培养和发展下一代科学劳动力。除此之外，还计划开展拓展活动，使学生了解如何从大豆等可持续资源中生产商业产品。本项目的总体目标是研究多金属活性位点，作为改善均相过渡金属催化剂活性和选择性的策略。该方法涉及设计新的配体类别，可以同时结合多种金属，同时还具有足够的电子灵活性，以实现两电子氧化还原过程，如氧化加成，还原消除和氧化偶联。这些催化剂将被研究用于（i）烯烃和1，3-二烯的偶联和环加成反应，（ii）使用定义明确的杂金属羰基簇的羰基化反应，和（iii）使用手性配体的不对称反应。该项目的主要智力价值在于它能够系统地调整多金属活性位点的组成，以获得对金属-金属协同效应的机械见解。在这样做的同时，Used团队还将通过使用地球上丰富的金属，如镍，钴和铁，开发可持续的反应。除此之外，从可持续化学的角度来看，这里选择开发的反应，即原料烯烃和小分子的环加成和偶联反应，在设计上是原子经济的，预计会产生最少的副产物。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Catalysis Program in the Division of Chemistry, Professor Christopher Uyeda of Purdue University is studying catalysts that contain multiple metals in their active sites. Many of the chemical compounds that are used in medicine, agriculture, and polymer chemistry have complex structures that require lengthy synthetic processes. Catalyst development is playing a critical role in improving the efficiency and sustainability of these processes by cutting the number of synthetic transformations required, by allowing more readily abundant starting materials to be used, and by minimizing the production of waste byproducts. Many of the catalysts currently used in the chemical industry contain only one metal in their active site. In contrast, many enzymes that carry out challenging reactions contain clusters of multiple metals in their active sites. Taking inspiration from biology, Dr. Uyeda’s research group is designing ligands that support the presence of multiple metals in their active site and is using them to carry out a number of organic transformations. Because a diverse group of high school, undergraduate, graduate, and postdoctoral researchers participate in this project, this work is also helping to train and develop the next generation scientific workforce. In addition to this, outreach activities are planned that will enable students to learn how commercial products are generated from sustainable resources, such as soybeans.The overarching goal of this project is to investigate multi-metallic active sites as a strategy to improve the activity and selectivity of homogeneous transition metal catalysts. The approach involves designing new classes of ligands that can bind multiple metals simultaneously while also possessing sufficient electronic flexibility to enable two-electron redox processes, such as oxidative addition, reductive elimination, and oxidative coupling. These catalysts will be investigated for (i) coupling and cycloaddition reactions of alkenes and 1,3-dienes, (ii) carbonylation reactions using well-defined heterometallic carbonyl clusters, and (iii) asymmetric reactions using chiral ligands. The primary intellectual merit of this project lies in its ability to systematically tune the composition of multi-metallic active sites to gain mechanistic insight into metal–metal cooperativity effects. While doing this, the Used team will also work to develop sustainable reactions by using earth abundant metals, such as nickel, cobalt, and iron. In addition to this, and important from a sustainable chemistry point of view, the reactions chosen for development here, cycloaddition and coupling reactions of feedstock olefins and small molecules, are by design atom-economical and are expected to produce minimal byproducts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.