Reactive Intermediates in Gold(I) Catalysis

金(I)催化中的反应中间体

基本信息

批准号：
1800273
负责人：
Ross Widenhoefer
金额：
$ 45万
依托单位：
Duke University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1800273&HistoricalAwards=false
关键词：
Reactive Intermediates Gold Catalysis

项目摘要

In this project funded by the Chemical Structure, Dynamics and Mechanisms B Program of the Chemistry Division, Professor Ross A. Widenhoefer in the Department of Chemistry at Duke University investigates the mechanisms of gold-catalyzed chemical reactions, especially those in which a divalent carbon atom is transferred to a carbon-carbon double bond to form a cyclopropane. This is a synthetic transformation of growing importance. Studies include experiments to determine the scope and mechanisms of gold-catalyzed processes and the structure of gold complexes. This research provides mechanistic insight that will serve the ever growing global community of researchers working toward the development of new and more efficient gold(I) catalyzed transformations. Research activities are fully integrated into the scientific education and training of graduate and undergraduate student researchers, including students from groups traditionally underrepresented in the sciences. Graduate students augment their research experience through participation in educational activities offered through the Duke University Graduate School. Graduate students also participate in community outreach activities in collaboration with Dr. Ben Bobay of the Duke Nuclear Magnetic Resonance (NMR) center which provide local high school students with hands-on exposure to modern high-field NMR spectroscopy and one-on-one instruction in the processing and interpretation of NMR data. This project investigates the structure and reactivity of gold carbenoid complexes and cationic gold carbene complexes, including those relevant to gold-to-alkene carbene transfer (cyclopropanation), gold alpha-oxo carbene and carbenoid complexes, and cationic beta, gamma-unsaturated gold carbene complexes. Despite a growing body of work in this area, limited experimental information is available regarding mechanisms which involve these gold complexes. Research activities fill important gaps in this field and develop an experimentally-grounded understanding of the nature of the complexes generated either through carbene transfer from stabilized diazo compounds or through the oxidation of alkenes in the presence of gold. The research addresses three main areas of inquiry: (1) elucidation of the mechanisms of gold to alkene carbene transfer by modeling the transition state for carbene transfer, independent synthesis of gold metallacyclobutane complexes, and kinetic analysis of gold to alkene carbene transfer under stoichiometric conditions; (2) evaluation of the nature and reactivity of cationic gold alpha-oxo carbene and carbenoid complexes by studying the reactions of gold complexes with stabilized N- and S-ylides and the reactions of pyridine N-oxides and with cationic gold complexes; and (3) interrogation of the structure and reactivity of unsaturated gold carbene complexes through the synthesis and characterization of cationic gold allenylidene and vinyl carbene complexes.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.

在该项目由化学结构，动力学和机制B计划资助的项目中，杜克大学化学系的罗斯·Widenhoefer教授调查了金催化的化学反应的机制，尤其是那些偏见的碳原子被转移到碳碳碳双键中，形成环丙烷的机制。这是越来越重要的综合转变。研究包括确定金催化过程的范围和机理的实验和金配合物的结构。这项研究提供了机械洞察力，该洞察力将为不断发展的全球研究人员社区服务，致力于开发新的，更有效的黄金（i）催化转化。研究活动已完全纳入研究生和本科生研究人员的科学教育和培训，包括传统上在科学中人数不足的团体的学生。研究生通过参加杜克大学研究生院提供的教育活动来增强他们的研究经验。研究生还与杜克核磁共振共鸣（NMR）中心的Ben Bobay合作参加了社区外展活动，该中心为当地的高中生提供了现代高场NMR光谱的动手接触，并在NMR数据的处理和解释中进行了一对一的指导。该项目研究了金甲苯络合物和阳离子金碳纤维复合物的结构和反应性，包括与金到烷烃转移（环丙烷化），金α-oxo carbene和carbenoid络合物以及阳离子β，伽玛无饱和金碳纤维复合物相关的阳离子。尽管该领域的工作越来越多，但有关涉及这些黄金复合物的机制的实验信息有限。研究活动填补了这一领域的重要空白，并对通过稳定的重氮化合物转移或通过在存在金的存在下氧化而产生的复合物的性质有了实验基础的理解。该研究涉及查询的三个主要领域：（1）通过建模碳烯转移的过渡状态，在静止条件下，将黄金转移的过渡状态，金金属酰基苯甲酸酯配合物的独立合成以及将金到烯烃转移的烯烃转移的动力学分析来阐明黄金到烯烃转移的机理；（2）通过研究金复合物与稳定的N-和S甲基的反应以及吡啶N-氧化物以及阳离子金配合物的反应，评估阳离子金α-oxo carbene和carbenoid复合物的性质和反应性；（3）通过合成和表征阳离子金甲烯基烯基烯基和乙烯基碳纤维络合物的不饱和金碳复合物的结构和反应性的询问。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力和更广泛影响的评估来通过评估来获得支持的值得审查。