Highly Electron-Deficient Carbon, Boron and Silicon Compounds

高度缺电子的碳、硼和硅化合物

• 批准号: 2246948
• 负责人: Guy Bertrand
• 金额: $ 55万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2246948&HistoricalAwards=false
• 关键词: Highly; Electron; Deficient; Carbon; Boron

With support from the Chemical Synthesis Program of the Chemistry Division, Professor Guy Bertrand of the Department of Chemistry and Biochemistry at the University of California – San Diego, is studying highly electron-deficient carbon, boron and silicon compounds. Usually atoms such as carbon, boron, and silicon contain a full octet, i.e. are surrounded by eight electrons when they form compounds with other atoms. This project seeks to isolate species that only possess 4 or 5 surrounding electrons. The isolation such compounds has been impeded by the belief that they are inherently unstable. However, by attaching groups that are specially designed to stabilize electron deficiencies stable compounds with these very low electron counts will be prepared. The availability of these stable versions provides a better understanding of chemical reaction mechanisms and opens the way for new applications. As an example, carbon compounds with six-valence electrons have become powerful tools in chemistry and have found medicinal and material science applications. This project will prepare carbon, silicon and boron with as few as four valence electrons. Although the work is fundamental in nature, the resulting species will certainly find a plethora of applications and benefit society at large. The laboratory of the PI is a joint venture between UCSD and the French CNRS. It serves to promote the exchange of undergraduates and graduates between UCSD and European Universities. The recent isolation of a monsubstituted carbene, namely an aminocarbene (R2NCH), demonstrates that an amino substituent can tame the intrinsic instability of a six-electron species. Therefore, the Bertrand team believes that using this principle compounds featuring a main-group element with only five- and even four-valence electrons can be isolated. Monocoordinated carbon compounds, namely amino carbynes (R2NC:●) and amino carbocations (R2NC:+), as well as the isoelectronic borylene radical anions (R2NB:●-) and borylenes (R2NB:) will be prepared. Apart from monocoordinate systems, dicoordinate carbon radical cations (R2C+●) and carbodications (R2C++), which also feature only five and four valence-electrons around the carbon atom and are the one and two electron oxidized forms of a carbene, respectively, are also being targeted. Once these electron-deficient species are in hand, their synthetic utility will be explored. As an illustration, carbodications R2C++ could find applications as strong Lewis acids, including in frustrated Lewis pair chemistry. This project which is at the nexus of physical, organic, inorganic and organometallic chemistry is well suited to the education of chemists at all levels.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.

在化学系化学合成项目的支持下，加州大学圣地亚哥分校化学与生物化学系的Guy Bertrand教授正在研究高度缺电子的碳、硼和硅化合物。通常，碳、硼和硅等原子包含一个完整的八隅体，即当它们与其他原子形成化合物时，被八个电子包围。该项目旨在分离出只拥有4或5个周围电子的物种。由于人们认为这些化合物本身不稳定，因此分离这些化合物受到了阻碍。然而，通过连接专门设计用于稳定电子缺陷的基团，将制备具有这些非常低的电子计数的稳定化合物。这些稳定版本的可用性提供了对化学反应机制的更好理解，并为新的应用开辟了道路。例如，具有六价电子的碳化合物已成为化学中的强大工具，并已发现医药和材料科学应用。该项目将制备碳、硅和硼，其价电子数少至4个。虽然这项工作在本质上是基础性的，但由此产生的物种肯定会找到大量的应用，并使整个社会受益。PI的实验室是UCSD和法国CNRS的合资企业。它有助于促进UCSD和欧洲大学之间的本科生和毕业生的交流。最近分离的单取代卡宾，即氨基卡宾（R2 NCH），表明氨基取代基可以驯服的六电子物种的固有不稳定性。因此，Bertrand团队认为，利用这一原理，可以分离出主族元素只有五价甚至四价电子的化合物。将制备单配位碳化合物，即氨基碳炔（R2 NC：●）和氨基碳阳离子（R2 NC：+），以及等电子亚硼基自由基阴离子（R2 NB：●-）和亚硼基（R2 NB：）。除了单配位系统之外，二配位碳自由基阳离子（R2 C +●）和碳二价阳离子（R2 C++）也是目标，它们也以碳原子周围仅5个和4个价电子为特征，并且分别是卡宾的一个和两个电子氧化形式。 一旦这些缺电子物种到手，它们的合成效用将被探索。举例来说，碳二价基团R2 C++可以用作强刘易斯酸，包括在受挫折的刘易斯对化学中。这个项目是在物理，有机，无机和有机金属化学的联系是非常适合在各级化学家的教育。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

An air-stable radical with a redox-chameleonic amide

具有氧化还原变色酰胺的空气稳定自由基

• DOI: 10.1039/d2cc05404c
• 发表时间: 2023
• 期刊: Chemical Communications
• 影响因子: 4.9
• 作者: Peltier, Jesse L.;Serrato, Melinda R.;Thery, Valentin;Pecaut, Jacques;Tomás-Mendivil, Eder;Bertrand, Guy;Jazzar, Rodolphe;Martin, David
• 通讯作者: Martin, David

A crystalline doubly oxidized carbene

结晶双氧化卡宾

• DOI: 10.1038/s41586-023-06539-x
• 发表时间: 2023
• 期刊: Nature
• 影响因子: 64.8
• 作者: Loh, Ying Kai;Melaimi, Mohand;Gembicky, Milan;Munz, Dominik;Bertrand, Guy
• 通讯作者: Bertrand, Guy

An Air-Stable “Masked” Bis(imino)carbene: A Carbon-Based Dual Ambiphile

空气稳定的“掩蔽”双（亚氨基）卡宾：碳基双亲两性化合物

• DOI: 10.1021/jacs.2c12847
• 发表时间: 2023
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Loh, Ying Kai;Melaimi, Mohand;Munz, Dominik;Bertrand, Guy
• 通讯作者: Bertrand, Guy