Increasing the Electrophilicity at Boron via Carborane Substituents

通过碳硼烷取代基增加硼的亲电性

• 批准号: 2349851
• 负责人: Caleb Martin
• 金额: $ 57.5万
• 依托单位: Baylor University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2349851&HistoricalAwards=false
• 关键词: Increasing; Electrophilicity; Boron; via; Carborane

With the support of the Chemical Synthesis program in the Division of Chemistry, Caleb Martin and his research team at Baylor University will study the synthesis of strong boron Lewis acids that feature non-conventional electron withdrawing substituents. Strong Lewis acids are essential to many important catalytic industrial and laboratory processes. Currently, boron compounds that contain fluorine are used in these reactions. However, there are pending Environmental Protection Agency mandates that will restrict the use of fluorine containing reagents that are set to begin 2025. Thus, replacements for the current boron-fluorine catalysts are essential. This project will develop an alternative to fluorine for boron-based catalysts for bond activation chemistry. This project also involves efforts to engage homeless high school students to stimulate their interest in science fields. Additionally, an annual advanced instrumentation workshop will host students and faculty from local small colleges.In this project, the Martin research team will synthesize boranes that feature icosahedral carborane clusters as electron withdrawing groups. A goal is to obtain boranes whose Lewis acidity is enhanced over that of their fluoroaryl counterparts. This enhancement will reflect electronic effects of the carborane substituent as well as the impact of carborane steric profiles upon the Lewis acid properties of these new boron-centered systems. The bulk and Lewis acidity of tris(ortho-carboranyl)borane will be investigated in frustrated Lewis pair chemistry. The other target, bis(1-methyl-ortho-carboranyl)borane, features a highly polar B-H bond. The reactivity of this bond as well as the stability of aryl variants will be studied. The proposed work will investigate the reactivity and properties of the newly synthesized borane Lewis super-acids. If successfully, the development of such new classes of non-fluorine-based boron-centered Lewis acids, could have a broad impact on synthetic and mechanistic chemistry, with implications for sustainable 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.

在化学系化学合成项目的支持下，贝勒大学的 Caleb Martin 和他的研究团队将研究具有非常规吸电子取代基的强硼路易斯酸的合成。强路易斯酸对于许多重要的催化工业和实验室过程至关重要。目前，这些反应中使用含氟硼化合物。然而，环境保护局尚未颁布指令，将从 2025 年开始限制含氟试剂的使用。因此，必须更换现有的硼氟催化剂。该项目将开发一种氟替代品，用于键活化化学的硼基催化剂。该项目还涉及吸引无家可归的高中生的努力，以激发他们对科学领域的兴趣。此外，一年一度的高级仪器研讨会将接待来自当地小型学院的学生和教师。在这个项目中，马丁研究团队将合成以二十面体碳硼烷簇为吸电子基团的硼烷。一个目标是获得路易斯酸度比氟代芳基对应物增强的硼烷。这种增强将反映碳硼烷取代基的电子效应以及碳硼烷空间分布对这些新的以硼为中心的系统的路易斯酸性质的影响。三（邻碳硼基）硼烷的本体酸度和路易斯酸度将在受阻路易斯对化学中进行研究。另一个目标双(1-甲基-邻碳硼基)硼烷具有高极性的 B-H 键。将研究该键的反应性以及芳基变体的稳定性。拟议的工作将研究新合成的硼烷路易斯超酸的反应性和性质。如果成功，此类新型非氟基硼中心路易斯酸的开发可能会对合成化学和机械化学产生广泛影响，并对可持续化学产生影响。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。