CAREER: Study and Design of Modular Aminophosphine Ligands for Cross-Coupling Reactions

在化学系化学催化项目的支持下，里士满大学的Miles Johnson博士正在研究提高交叉偶联反应催化剂的效率和可持续性的方法。交叉偶联反应是指将碳基构建块连接成大分子的化学转化。交叉偶联反应广泛应用于化学工业，促进这些反应的催化剂依赖于与金属中心结合的称为配体的分子。约翰逊博士和他的研究小组正在开发新的配体，以确定与丰富的第一行过渡金属促进快速和选择性催化的特征。这些配体很容易制备，并且可以系统地进行修饰，以识别和调整控制催化的属性。约翰逊博士研究团队的本科生研究人员和里士满大学实验室课程的本科生正在共同准备这些新的配体并研究它们的活性。为了提高不同教育水平的STEM学科的可及性，Johnson博士还担任里士满大学综合科学体验（URISE）的导师，该计划旨在支持STEM中代表性不足的群体的学生向大学过渡，并参加研讨会，让里士满地区的高中生和他们的老师参与大学校园的化学。Miles Johnson和他的研究小组正在设计和测试氨基膦配体，以发现新的交叉偶联反应，并了解现有反应的机制。这些配体的模块化合成旨在识别控制C-N， C-B和C-O成键反应活性的关键空间和电子性质。正在开发模型，将这些配体的显著特征与它们在交叉偶联过程中赋予的反应性联系起来。这些研究对于支持可持续的第一行过渡金属催化剂的持续发展至关重要，这些催化剂不像贵金属类似物那样被很好地理解。Johnson组的本科生、实验课程和一年级前的课程被整合在一起，为各种不同类型的学生提供参与本研究项目的机会，并获得解决与可持续化学相关问题的实践经验。该奖项反映了美国国家科学基金会的法定使命，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, Dr. Miles Johnson of the University of Richmond is developing ways to improve the efficiency and sustainability of catalysts for cross-coupling reactions – chemical transformations that link carbon-based building blocks into larger molecules. Cross-coupling reactions are used extensively in chemical industry and the catalysts that promote these processes depend on molecules that are bound to the metal center called ligands. Dr. Johnson and his research group are developing new ligands to identify characteristics that promote fast and selective catalysis with abundant first row transition metals. These ligands are easy to prepare and can be modified in a systematic way to identify and tune the attributes that control catalysis. Undergraduate researchers on Dr. Johnson’s research team and undergraduate students in laboratory courses at the University of Richmond are working together to prepare these new ligands and study their activity. To improve accessibility to STEM disciplines at different levels of education, Dr. Johnson is also serving as a mentor for the University of Richmond Integrated Science Experience (URISE), a program intended to support students from groups underrepresented in STEM during their transition to college, and participating in workshops to engage Richmond area high school students and their teachers in chemistry on the University campus.Dr. Miles Johnson and his research group are designing and testing aminophosphine ligands to discover new cross-coupling reactions and understand the mechanisms of existing ones. The modular synthesis of these ligands is designed to enable identification of the key steric and electronic properties that control reactivity in C–N, C–B, and C–O bond-forming reactions. Models are being developed to correlate the salient features of these ligands with the reactivity that they impart in cross-coupling processes. These studies are critical for supporting the continued development of sustainable first row transition metal catalysts that are not as well understood as their precious metal analogues. Undergraduates in the Johnson group, laboratory courses, and a pre-first year program have been integrated to provide opportunities for a variety of different types of students to contribute to this research program and obtain hands-on experience in solving problems relevant to sustainable chemistry.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.