Design, Synthesis, and Reactivity of Diboryl- and Aminoboryl Carbenes

正在合成在碳上缺乏电子的类碳化合物。虽然大多数化合物的特征是碳原子形成四个化学键，但也有少数碳原子形成三个或更少的化学键。人们认为这些新的碳物种本身就不稳定，这阻碍了它们的分离。这个项目将使用PI开发的方法来制备一种叫做碳烯的化合物，这种化合物只含有两个碳键。在这个项目中，这些方法将扩展到以前未知的碳原子与两个硼原子结合的碳烯。这些物种的可用性有可能增加我们对碳的化学反应如何发生的理解，允许控制含碳化合物的反应性。最终，从这些研究中得出的结果有望通过提供更多选择性的合成方法来推进精细化学品和材料的制造。Hudnall教授的实验室参与了当地与高中的外展活动，一个儿童博物馆将整个社区与本科生和研究生的研究联系起来。自20世纪60年代以来，单线态碳烯具有p2电子构型的想法已经理论化，但到目前为止，这些物种基本上没有在实验室中被分离出来。利用主要研究者开发的合成方法，二硼基碳烯（R2B-C-BR2）和相关的氨基碳烯（R2N-C-BR2）将被制备。由于一些目标物种可能是不可分离的，因此该研究项目被视为高风险/高回报的努力。预测目标二硼基碳烯具有p2电子构型，这一构型在其他碳烯中没有观察到。重要的是，这些碳化合物被预测在碳原子上具有相当的亲电性，并可能为新的碳化合物反应性流形提供机会。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。

is synthesizing compounds of the carbenoid class that formally are electron deficient at carbon. While most compounds feature carbon atoms that form four chemical bonds, there are a handful in which carbons form three or fewer bonds. The isolation of such new carbon species has been impeded by the belief that they are inherently unstable. This project will use methods developed by the PI to prepare compounds called carbenes, which contain only two bonds to carbon. In this project, these methods will be extended to previously unknown carbenes where the carbon atom is bonded to two boron atoms. The availability of these species has the potential to add to our understanding of how chemical reactions of carbon take place, permitting control of the reactivity of carbon-containing compounds. Ultimately, results derived from these studies are expected to advance the manufacturing of fine chemicals and materials by providing more selective approaches to synthesis. Professor Hudnall's laboratory participates in local outreach activities with high schools, a children’s museum to connect the community at large with undergraduate and graduate research.The idea that singlet carbenes feature a p2 electronic configuration has been theorized since the 1960s, but thus far these species have largely eluded isolation in the laboratory. Utilizing synthetic methodologies developed by the principal investigator, diborylcarbenes (R2B-C-BR2) and the related aminoboryl carbenes (R2N-C-BR2) will be prepared. As some of the targeted species may be non-isolable, this research project is seen as a high risk/high reward effort. The targeted diborylcarbenes are predicted to have the p2 electron configuration, a configuration not observed in other carbenes. Importantly, these carbenes are predicted to be quite electrophilic at the carbene carbon atom and may provide opportunities for new manifolds of carbene reactivity.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.