CAREER: Bridging Synthesis and Computational Chemistry to Parameterize Noncovalent Interactions in Asymmetric Catalysis

美国南密西西比大学（USM）化学系化学催化项目和促进竞争性研究的既定项目（EPSCoR）共同支持Julie A. Pigza教授的研究项目。Pigza研究小组正在研究新的催化剂，将石油和生物质原料转化为社会使用的重要化学品。改进的催化剂在减少环境浪费的同时满足了对重要化学构建块的更广泛的社会需求。该研究正在使用计算方法来了解催化剂如何工作，以使其改进和有用。为了实现这些目标，研究生和本科生正在进行这个项目的综合、机械和计算方面的研究。这丰富了密西西比州的跨学科研究培训。本研究介绍了两种教育策略，以招募和保留代表性不足的群体进入STEM研究。第一个是社区大学桥梁项目，通过真实的研究经验、专业发展研讨会和同伴指导关系，支持STEM转专业学生向USM过渡。第二种机制是计算化学迷你课程，重点是利用USM现有的nsf资助的超级计算设施进行催化。用双功能氢键供体和受体有机催化剂形成碳-碳或碳杂原子键已成为过渡金属催化的可行替代方法。这些有机催化剂的一个关键优点是利用了现有官能团的固有反应性。本研究将化学合成与计算量子化学相结合，研究催化剂与底物之间的非共价相互作用。本研究的目标是对模拟生物系统中发现的小分子催化体设计有更深入的基本理解。具体来说，使用密度泛函理论对催化剂和底物之间的芳香pi-pi稳定相互作用进行了系统的研究，以参数化这些微妙的非共价相互作用并对其重要性进行排序。具体目标是探索未被开发的键转化，如：(i)无过渡金属的不对称烯丙基烷基化，（ii）手性无环醚的产生，以及（iii）两亲性甲基亲核试剂的形成及其在pi键上的添加。综合教育和研究组成部分旨在培养海湾南部地区高中，本科生和研究生的多样化STEM劳动力，重点是那些传统上不接触研究的学生，包括社区大学生。这项工作还利用了大学内现有的nsf资助的超级计算设备。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。

The Division of Chemistry Chemical Catalysis Program and the Established Program to Stimulate Competitive Research (EPSCoR) jointly support the research program of Professor Julie A. Pigza at the University of Southern Mississippi (USM). The Pigza research group is investigating new catalysts to transform petroleum and biomass feedstocks into important chemicals used in society. The improved catalysts meet the broader societal needs for important chemical building blocks while reducing environmental waste. The investigation is using computational methods to understand how the catalysts work to enable their improvement and usefulness. To accomplish these goals, graduate and undergraduate students are carrying out the synthetic, mechanistic, and computational aspects of this project. This is enriching interdisciplinary research training in the state of Mississippi. This research introduces two educational strategies to recruit and retain underrepresented groups into STEM research. The first is a Community College Bridge Program that is supporting STEM transfer student majors in their transition to USM through an authentic research experience, professional development workshops, and peer mentoring relationships. The second mechanism is a computational chemistry mini-course with a focus on catalysis utilizing an existing NSF-funded supercomputing facility at USM. The formation of carbon-carbon or carbon-heteroatom bonds with bifunctional hydrogen bond donor and acceptor organocatalysts has emerged as a viable alternative to transition metal catalysis. A key benefit to these organocatalysts is the exploitation of the innate reactivity of existing functional groups. This research investigates the ensemble of noncovalent interactions between a catalyst and substrate by combining chemical synthesis and computational quantum chemistry. The goal of this research is a deeper fundamental understanding of small molecule catalophore design mimicking those found in biological systems. Specifically, the systematic investigation of aromatic pi-pi stabilizing interactions between the catalyst and substrate is pursued using density functional theory to parameterize and rank the importance of these subtle non-covalent interactions. The specific aims probe underexplored bond transformations such as: (i) a transition metal-free asymmetric allylic alkylation, (ii) the generation of chiral, acyclic ethers, and (iii) the formation of ambiphilic methine nucleophiles and their addition to pi-bonds. The integrated educational and research components serve to train a diverse STEM workforce of high school, undergraduate, and graduate students within the Gulf South region with a focus on those students traditionally not exposed to research including community college students. This work also takes advantage of an existing NSF-funded supercomputing facility within the University.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.