Stereocontrolled and Aerobic Oxidative Reactions at High-Valent Nickel Centers

高价镍中心的立体控制和有氧氧化反应

• 批准号: 1800470
• 负责人: Liviu Mirica
• 金额: $ 45万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1800470&HistoricalAwards=false
• 关键词: Stereocontrolled; Aerobic; Oxidative; Reactions; Valent

With funding from the Synthesis Program of the Chemistry Division, Dr. Liviu Mirica of the Department of Chemistry at Washington University in St. Louis is investigating the role of nickel compounds in important chemical transformations. These include reactions that couple two different molecular partners ("cross-coupling") with improved selectivity, as well as reactions related to the activation of inert organic substrates with oxygen. Cross-coupling reactions sped up by metal-containing compounds have become indispensable in the synthesis of a large number of important chemicals, pharmaceuticals, and materials. While palladium-based catalysts are the most commonly used, Dr. Mirica is synthesizing and studying nickel (Ni)-based catalysts as they may be able to react with a wider variety of target molecules and with more specificity. In addition, Professor Mirica has established a collaboration with Professor Tim Hubin from Southwestern Oklahoma State University (SWOSU), a regional university in Oklahoma that has an appreciable amount of students that belong to underrepresented groups. Professor Hubin and his students collaborate on the synthesis of some of the targeted catalysts, visiting the Mirica lab, and performing reactivity studies using their chemical systems. This experience exposes the undergraduate students to an R1 research institution, and inspires them to pursue advanced degrees in chemistry. Professor Mirica and his group continue to work closely with collaborators from Spain and South Korea. This collaborative experience is an excellent training ground to prepare them to work in a true international environment, very similar to a multinational corporation.While palladium (Pd)-based catalysts are arguably the most commonly used in cross-coupling reactions, Ni-based cross-coupling catalysts have been developed recently. Given their ability to engage alkyl electrophiles and nucleophiles in stereospecific or stereoselective transformations the Ni-based catalysts are of interest. By comparison to the Pd-mediated transformations that generally employ diamagnetic intermediates, the Ni systems can more easily undergo one-electron redox reactions and lead to additional reaction pathways. The presence of paramagnetic Ni(I) and Ni(III) species makes reactivity characterization more difficult. Dr. Mirica's laboratory is synthesizing isolated organometallic Ni(III) and Ni(IV) complexes supported by flexible multidentate ligands and studying in detail their involvement in important chemical transformations such as stereocontrolled C-C bond formation reactions and aerobic oxidative reactions mediated by high-valent Ni intermediates. This work has direct relevance to C-H functionalization and C-C / C-heteroatom bond formation reactions. Dr. Mirica is also recruiting graduate and undergraduate students from different backgrounds and providing them with an interdisciplinary training that spans inorganic, organic, and physical 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.

在化学部合成计划的资助下，圣路易斯华盛顿大学化学系的Liviu Mirica博士正在研究镍化合物在重要化学转化中的作用。这些反应包括两个不同的分子伴侣（“交叉偶联”）具有提高的选择性，以及与氧有有机底物与氧气激活相关的反应。在合成大量重要化学物质，药品和材料的合成中，通过含金属化合物加速的交叉偶联反应是必不可少的。虽然最常用的钯催化剂是基于钯的催化剂，但Mirica博士正在合成和研究基于镍（NI）的催化剂，因为它们可能能够与更多种目标分子反应，并且具有更特异性。 此外，Mirica教授与俄克拉荷马州西南部大学（SWOSU）的Tim Hubin教授建立了合作，这是俄克拉荷马州的一所地区大学，该大学拥有可属于代表性不足的群体的可观学生。 Hubin教授和他的学生合作了一些靶向催化剂的合成，参观Mirica Lab，并使用其化学系统进行反应性研究。 这种经验使本科生接触了R1研究机构，并激发了他们攻读化学高级学位。 米里卡教授和他的小组继续与西班牙和韩国的合作者密切合作。这种协作经验是一个很好的培训理由，可以使他们在真正的国际环境中工作，这与跨国公司非常相似。钯（PD）基于基于跨国公司的催化剂可以说是在跨偶联反应中最常用的，但最近已经开发了基于NI的交叉耦合催化剂。 鉴于它们有能力使烷基电力和亲核试剂参与立体特异性或立体选择性转化，因此基于NI的催化剂很感兴趣。通过与通常采用Dimagnetic中间体的PD介导的转化相比，NI系统可以更容易地经历单电子氧化还原反应并导致其他反应途径。 顺磁性Ni（I）和Ni（III）物种的存在使反应性表征更加困难。 Mirica博士的实验室正在综合柔性多培养基配体支持的孤立有机金属Ni（III）和Ni（IV）配合物，并详细研究它们参与重要的化学转化，例如立体控制的C-C键形成反应和有氧氧化反应和有氧氧化反应，并被高级ni Intermedmedipiates介导的有氧氧化反应。这项工作与C-H功能化和C-C / C杂化键形成反应有直接相关。 Mirica博士还正在招募来自不同背景的研究生和本科生，并为他们提供了跨学科培训，跨越无机，有机和物理化学的培训。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来通过评估来获得支持的。