SusCHEM: Catalytic Alkene Transformations Using High-Spin Cobalt Complexes

有了这个奖项，化学部的化学催化计划正在资助耶鲁大学的帕特里克荷兰教授研究新的催化剂，用于将碳氢化合物转化为更复杂的化学品。 高效的催化反应是可持续化学的关键部分，最理想的催化反应利用丰富且廉价的金属。由于成本、地理可用性和环境友好性，钴等廉价的“贱金属”比铂等贵金属更可持续。 在过去的十年里，人们发现了选择性贱金属催化剂，但它们的反应性缺乏概念基础。该项目致力于开发比现有催化剂更便宜的含钴催化剂，并提供可应用于精细化学品生产的新产品。正在开发对催化剂进行的键形成和键断裂反应的基本理解，这为对潜在化学原理感兴趣的更广泛的化学家提供了信息。项目参与者还参与为康涅狄格州纽黑文的高中化学学生制定和实施关于可持续性的新教学模块。这些模块释放了学生对科学、技术、工程和数学（STEM）领域的好奇心，并提高了公众对化学的看法。Holland教授正在研究使用钴的高自旋有机金属络合物进行烯烃转化的催化系统。这些廉价的钴催化剂具有不同于传统贵金属催化剂的动力学选择性，并展示了新的贱金属催化反应所带来的机会。在催化的实际发展正在补充的机制研究和DFT计算，阐明自旋状态交叉在反应过程中的作用。机理和计算研究为高自旋第一列催化剂的合理设计提供了基本依据。这些研究策略主要应用于两个特定的目标，烯烃异构化和烯烃氢化硅烷化。烯烃异构化的研究主要集中在具有高区域选择性和立体选择性的钴催化剂上。烯烃硅氢加成反应的研究主要集中在开发用于烯烃的稳健和快速的反马尔可夫硅氢加成反应的钴催化剂。这两个反应也被合并在串联异构化-氢化硅烷化反应中，将烯烃的混合物转化为单一的所需产物。

With this award, the Chemical Catalysis Program of the Chemistry Division is funding Professor Patrick Holland of Yale University to study new catalysts for the transformation of hydrocarbons to more complex chemicals. Efficient catalytic reactions are a key part of sustainable chemistry, and the most desirable catalytic reactions utilize metals that are both abundant and inexpensive. Inexpensive "base metals," such as cobalt, are more sustainable than precious metals, such as platinum, because of cost, geographic availability, and environmental friendliness. The last decade has seen the discovery of selective base metal catalysts, but their reactivity has less conceptual underpinning. This project endeavors to develop cobalt-containing catalysts that are cheaper than existing catalysts and that give new products that can be applied to fine chemical production. A fundamental understanding of the bond-forming and bond-breaking reactions performed by the catalyst is being developed, which informs a broader range of chemists interested in the underlying chemical principles. The project participants are also involved in the development and implementation of new teaching modules on sustainability for high-school chemistry students in New Haven, Connecticut. These modules are unlocking the students' curiosity about Science, Technology, Engineering, and Mathematics (STEM) fields in the context of the environment and improving the public perception of chemistry.Professor Holland is studying catalytic systems that perform alkene transformations using high-spin organometallic complexes of cobalt. These inexpensive cobalt catalysts have kinetic selectivities that differ from traditional precious metal catalysts and demonstrate the opportunities that arise from new base metal-catalyzed reactions. The practical developments in catalysis are being complemented by mechanistic studies and DFT computations that elucidate the roles of spin-state crossover during the reactions. Mechanistic and computational studies are providing a fundamental basis for the rational design of high-spin, first-row catalysts. These research strategies are being applied primarily to two specific targets, alkene isomerization and alkene hydrosilylation. Studies on alkene isomerization are focusing on cobalt catalysts for the conversion of terminal alkenes to Z-2-alkenes with high regioselectivity and stereoselectivity. Studies on alkene hydrosilylation are focusing on developing cobalt catalysts for the robust and rapid anti-Markovnikov hydrosilylation of alkenes. The two reactions are also being combined in tandem isomerization-hydrosilylation reactions that convert mixtures of alkenes into a single desired product.