Exploring and Understanding the Effect of Cation-Pi Interactions in Asymmetric Catalysis

在该项目中，由化学部的化学结构，动力学和机制-B计划资助，南卡罗来纳州大学化学和生物化学系的Sheryl Wiskur教授试图了解分子间相互作用如何控制化学反应，以合理设计催化剂。光学活性中间体在制药和农业化学工业中的重要性日益增加。 获得这些商业上重要的化合物的新方法正在不断开发。 为了合理设计催化剂，理解有助于实现选择性产物形成的相互作用是重要的。本研究探讨了分子间的相互作用，称为阳离子π相互作用，参与控制选择性。这项研究可以帮助开发更有效的不对称催化剂，这是药物开发和许多其他化学品制造所需要的。该项目还考虑到研究生在进行实验以了解这种超分子相互作用时所接受的宝贵培训。 更广泛的影响包括指导女科学家以帮助留住科学界的女性。离域阳离子通常被提议通过底物和催化剂之间的阳离子-π相互作用来帮助控制不对称反应，但离域阳离子尚未得到广泛的研究。 该项目以两种方式探索这种超分子相互作用。 研究了四种常见的有机催化剂核结构的键合热力学。 该团队还将研究结合趋势如何与π系统上的电子改变的模型反应的速率和选择性相关。 结合的静电计算探讨了解绑定方向和本地化的电荷。阳离子中的电子变化（即，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。

In this project, funded by the Chemical Structure, Dynamics and Mechanisms-B Program of the Chemistry Division, Professor Sheryl Wiskur of the Department of Chemistry and Biochemistry at the University of South Carolina is attempting to understand how intermolecular interactions control chemical reactions in order to rationally design catalysts. Optically active intermediates are of increasing in importance in the pharmaceutical and agrochemical industries. New approaches to obtaining these commercially important compounds are constantly being developed. It is important to understand the interactions that aid in achieving selective product formation in order to rationally design catalysts. This research investigates how the intermolecular interactions, termed a cation-pi interactions, are involved in controlling selectivity. The research could aid the development of more efficient asymmetric catalysts, which are needed in drug development and the manufacture of many other chemicals. The project also takes into account the valuable training graduate students receive while carrying out the experiments to understand this supramolecular interaction. Broader impacts include the mentoring of women scientists to aid in retaining women in science.Delocalized cations are often proposed to aid in controlling asymmetric reactions through cation-pi interactions between the substrate and catalyst, yet delocalized cations have not been as widely studied. This project explores this supramolecular interaction in two ways. The thermodynamics of binding of four common organocatalyst core structures will be studied. The team will also investigate how the binding trends relate to the rate and selectivity of a model reaction as electronics on the pi system are altered. The electrostatics of binding are explored computationally to understand binding orientations and localization of charge. The electronic changes in the cation (i.e., substituted catalysts) are examined to understand how those changes affect the same model reaction in terms of thermodynamics, kinetics, and selectivity.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.