RUI: Mechanisms of C-F and S-F Bond Activation and Cross-coupling with Bidentate N-heterocyclic Carbene Nickel Catalysts

在这个RUI项目中，波莫纳州立理工大学化学系的S. Chantal E. Stieber在化学系化学结构、动力学和机理b项目的支持下，正在研究地球上丰富的镍催化剂，用于将氟安装到分子上，未来有可能用于成像和制药。这项工作的目的是确定镍催化剂的结构如何影响碳氟键和硫氟键的反应性，以及由此产生的催化性能。这项工作包括在一个主要的本科院校为学生提供先进的有机金属、有机和无机研究培训。这笔拨款将额外支持带薪的夏季研究培训职位，开发新的研究教程视频，以及举办不同的研讨会演讲者。这些努力结合起来，将扩大对科学的参与，并在一个资源不足的为西班牙裔服务的机构提供劳动力培训。用于碳氟和硫氟活化的镍系统尚未被广泛探索，但有可能为在分子上安装氟以进行19F标记、硅基化和硼基化提供新的途径。这项工作将探讨镍对氟芳基和氟磺基中碳氟键和硫氟键的基本反应性作为配体环境的函数及其对交叉偶联反应的影响。将合成一系列双齿n-杂环碳（NHC）镍配合物，以回答以下问题：(i)配体和底物如何影响镍上碳氟或硫氟键的顺式或反式氧化加成？（二）镍上碳氟键和硫氟键的顺式氧化加成与反式氧化加成是否会影响硅基化和硼基化催化的交叉偶联反应活性？（三）与芳基氟化物相比，镍如何与磺酰氟化物反应？这些研究有望为Ni-NHC配合物的结构特征提供基本信息，这些结构特征赋予了最大的反应活性，以激活C-F和S-F键。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。

In this RUI project, with support from the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, S. Chantal E. Stieber of the Department of Chemistry at California State Polytechnic University, Pomona is studying earth-abundant nickel catalysts for installing fluorine onto molecules with potential for future use in imaging and pharmaceuticals. The goal of this work is to determine how the structure of the nickel catalyst affects the reactivity with carbon-fluorine and sulfur-fluorine bonds, and the resulting catalytic performance. This work involves advanced organometallic, organic, and inorganic research training for students at a primarily undergraduate institution. This grant will additionally support paid summer research training positions, development of new research tutorial videos, and hosting diverse seminar speakers. Combined, these efforts will broaden participation in science and provide workforce training at an under-resourced Hispanic-serving institution. Nickel systems for carbon-fluorine and sulfur-fluorine activation are not widely explored, but have the potential to provide new routes for installing fluorine on molecules for 19F labeling, silylation, and borylation. This work will probe the fundamental reactivity of nickel toward carbon-fluorine and sulfur-fluorine bonds in aryl fluorides and sulfonyl fluorides as a function of the ligand environment and resulting effects on cross-coupling reactions. A series of bidentate N-heterocyclic carbene (NHC) nickel complexes will be synthesized to answer the following questions: (i) How do the ligand and the substrate affect cis- versus trans-oxidative addition of carbon-fluorine or sulfur-fluorine bonds at nickel? (ii) Does cis- versus trans-oxidative addition of carbon-fluorine and sulfur-fluorine bonds at nickel affect cross-coupling reactivity for silylation and borylation catalysis? and (iii) How does nickel react with sulfonyl fluorides as compared to aryl fluorides? These studies are expected to provide fundamental information on the structural features that confer maximal reactivity on Ni-NHC complexes for C-F and S-F bond activation.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.