Probing the Solution-Phase Dynamics of l3-Iodanes and Relation to Reactivity

在这个由化学系化学结构、动力学机制B计划资助的项目中，波特兰州立大学化学系的大卫·斯图尔特教授正在研究有机碘化学试剂。 本研究的目的是了解分子结构和反应介质如何相互作用，以影响这些化合物在化学反应中的整体行为。 该项目位于物理和合成有机化学的界面，最终应用于健康，农业和技术;它非常适合在高等教育环境中培养科学家。 波特兰州立大学是一个多元化的机构，是培养科学代表性不足的学生。 Stuart教授的团队与精细化工行业的合作将促进基础发现更快地转化为更广泛的科学界的应用。高价碘试剂通常用作化学合成中的催化剂、引发剂、试剂和氧化剂，因为它们与已建立和新兴的反应范式（如离子反应、金属介导/催化反应和自由基反应）结合良好。静电相互作用是高价碘化合物扩展配位中键合的组成部分，假设它们发生在聚集和刘易斯酸碱化学过程中，对反应性和应用有直接影响。 这个项目的目标是解开的结构和溶剂效应，影响溶液相的相互作用与反应化学的高价碘化合物。这是通过合成单芳基和二芳基碘鎓化合物的设计库，进行核磁共振和质谱滴定实验，通过非线性回归将滴定数据拟合到结合模型，并分析线性自由能关系和反应动力学来实现的。通过1）量化和利用芳基的刘易斯酸性，可以更深入地理解高价碘在溶液相中的行为（2，4，6-三甲氧基苯基）碘鎓盐和相关衍生物，2）评估这些盐的溶液相聚集对反应性和选择性的影响，和3）芳基碘烷与Bronsted-该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查评估的支持的搜索.

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor David Stuart of the Department of Chemistry at Portland State University is studying organoiodine chemical reagents. The goal of this research is to understand how the molecular structure and the reaction medium interact to influence overall behavior of these compounds in chemical reactions. The project lies at the interface of physical and synthetic organic chemistry with eventual applications in health, agriculture, and technology; it is well-suited to the training of scientists in a higher-education setting. Portland State University is a diverse institution and is well-positioned for training underrepresented students in sciences. Collaboration between the Professor Stuart's group and the fine-chemical industry will facilitate a more rapid translation of fundamental discoveries into applications by the broader scientific community.Hypervalent iodine reagents are routinely used as catalysts, initiators, reagents, and oxidants in chemical synthesis because they integrate well with established and emerging reactivity paradigms such as ionic, metal-mediated/catalyzed, and radical reactions. Electrostatic interactions are an integral component of bonding in the expanded coordination of hypervalent iodine compounds and the hypothesis is that they occur during aggregation and Lewis acid-base chemistry with a direct impact on reactivity and applications. The goal of this project is to unravel the structure and solvent effects that influence solution-phase interactions of hypervalent iodine compounds with a clear link to reaction chemistry. This is to be achieved by synthesizing designed libraries of monoaryl and diaryliodonium compounds, conducting nuclear magnetic resonance and mass spectrometry titration experiments, fitting titration data to binding models by non-linear regression, and analyzing linear Free-energy relationships and reaction kinetics. A deeper understanding of the behavior of hypervalent iodine in the solution phase will be obtained by 1) quantifying and exploiting the Lewis acidity of aryl(2,4,6-trimethoxyphenyl)iodonium salts and related derivatives, 2) assessing the influence of solution-phase aggregation of these salts on reactivity and selectivity, and 3) activation of aryl iodanes with Bronsted-Lowry acids.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.