CAS: A Rethinking of Borrowing Hydrogen: from Ligand Design to New Reactions and Mechanisms

在化学系化学催化项目的支持下，中田纳西州立大学的丁凯英将研究导致碳-碳或碳-杂原子键形成的催化反应。这些反应将由新的地球丰富的金属催化系统，利用“借用氢（BH）”途径介导。这种BH途径是环境友好的，在生产增值化学品方面具有原子和工艺效率，同时产生水作为唯一的副产品。 结构-反应性的相关性将被研究，以收集这些催化剂如何在分子水平上促进这种化学反应的关键信息。研究结果将用于指导催化剂开发新的和具有挑战性的反应。本计画将提供学生在合成无机化学、有机化学与催化的研究经验。教育活动包括努力加强来自服务不足群体和低收入或第一代家庭的本科生的参与，参加夏季研究营，以及将资助的研究纳入教学实验室。研究和教育活动的更广泛影响将有助于在化学科学领域创造更多样化和更受教育的劳动力。中田纳西州立大学的Keying Ding博士和她的研究团队将研究新的碱过渡金属催化剂，以解决利用“借氢”机理途径的催化反应中出现的挑战。一个新的家庭的双功能配体，功能反应性悬垂臂，潜在地促进氢转移反应，通过金属配体的协同性，并含有刚性配体支架，以提供稳定性，将被合成和表征。碱过渡金属络合物的催化活性将被确定，重点是（i）建立对BH催化过程的深入理解，（ii）消除对BH反应中使用过量强碱的依赖，以及（iii）提高产物选择性。新的概念和见解的使用地球丰富的金属代替贵过渡金属的BH和相关的转换，预计将产生从这些研究，以帮助指导未来的催化剂的发展。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的知识价值和更广泛的影响审查标准。

With the support of the Chemical Catalysis program in the Division of Chemistry, Keying Ding of Middle Tennessee State University will study catalytic reactions that result in the formation of carbon–carbon or carbon–heteroatom bonds. These reactions will be mediated by new earth-abundant metal catalytic systems that utilize the “borrowing hydrogen (BH)” pathway. This BH pathway is environmentally friendly and atom- and process-efficient in producing value-added chemicals while producing water as the sole byproduct. Structure-reactivity correlations will be studied in an effort to glean critical information on how these catalysts facilitate this chemistry at the molecular level. The results will be used to direct catalyst development toward new and challenging reactions. This project will offer research experiences for students at the interface of synthetic inorganic chemistry, organic chemistry, and catalysis. The educational activities include efforts to enhance the participation of undergraduate students from underserved groups and low-income or first-generation families, participation in a summer research camp, and the integration of the funded research into teaching laboratories. The broader impacts of the research and educational activities will assist in the creation of a more diverse and educated workforce in the chemical sciences.Dr. Keying Ding and her research team at Middle Tennessee State University will study new base-transition metal catalysts to address emerging challenges in catalytic reactions that utilize the “borrowing hydrogen” mechanistic pathway. A new family of bifunctional ligands that feature reactive pendant arms that potentially promote hydrogen transfer reactions via metal-ligand cooperativity, and that contain rigid ligand scaffolds to provide stability, will be synthesized and characterized. The catalytic activities of the base transition-metal complexes will be determined with a focus on (i) establishing an in-depth understanding of the BH catalytic process, (ii) eliminating the dependence on the use of excess strong base in the BH reactions, and (iii) improving the product selectivity. New concepts and insights on the use of earth-abundant metals in place of precious transition metals for BH and related transformations are expected to arise from these studies to help guide the development of future catalysts.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.