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合成具有非常规吸电子取代基的强硼路易斯酸。强路易斯酸是许多重要的催化工业和实验室过程所必需的。目前，含氟的硼化合物被用于这些反应。然而，美国环境保护署（Environmental Protection Agency）将于2025年开始限制含氟试剂的使用。因此，替代目前的硼氟催化剂是必不可少的。该项目将开发用于键活化化学的硼基催化剂的氟替代品。这个项目还包括努力吸引无家可归的高中生，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，Martin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。目标是获得刘易斯酸度高于其氟芳基对应物的硼烷。这种增强反映了碳硼烷取代基的电子效应以及碳硼烷立体分布对新硼中心体系Lewis酸性质的影响。在受挫路易斯对化学中研究了三（正碳硼基）硼烷的体积和路易斯酸度。另一个目标，双（1-甲基-邻碳硼基）硼烷，具有高极性的B-H键。该键的反应性以及芳基变异体的稳定性将被研究。本文将研究新合成的硼烷刘易斯超酸的反应性和性质。如果研制成功，这类新型非氟基硼中心路易斯酸将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。