Lewis Base Directed Intermolecular Hydrogen Atom Transfer

在化学系化学合成项目的支持下，约翰霍普金斯大学的Thomas Lectka教授正在研究一种新方法，可以选择性地修改一个复杂分子中的一个碳氢键，而这个分子具有许多碳氢键。这些类型的反应对于系统地改变生物活性分子来研究它们的反应性非常重要，而不必从头开始构建每个单独的分子。Lectka教授和他的研究小组正在确定复杂分子中的基因座是如何与碳氢键激活剂相互作用的，并利用这些信息来预测和提高选择单个碳氢键进行激活的能力。在这些研究中，碳氢键被转化为碳氟键、碳溴键、碳氧键和碳氮键，这是有机合成中有价值的碳氢活化转化。Lectka教授还与JHU女性科学与工程（WISE）项目和JHU- nsf STEM成就在巴尔的摩小学（SABES）项目合作，为当地高中生提供研究经验。由于希望能够研究和修饰天然产物和药物靶标，而无需从基本构建块单独制备每种类似物，复杂分子环境中的位点选择性C-H功能化是当前的一个巨大挑战。Lectka教授和他的研究小组正在研究一种解决这个问题的新方法，通过开发氢原子转移试剂，这种试剂可以特异性地与底物协调，并选择性地激活单个碳氢键以形成C-X键。同时，该团队也在探索酮和烯酮以外的功能基团类型，这些功能基团可以影响氢原子转移试剂的选择性，并确定底物配位对金属添加剂的影响。这些活动为研究生的专业发展和本科生的研究体验提供了强大的训练平台。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。

With support from the Chemical Synthesis Program in the Division of Chemistry, Professor Thomas Lectka of Johns Hopkins University is studying new ways to selectively modify one carbon-hydrogen bond in a complex molecule that features many carbon-hydrogen bonds. These types of reactions are important for systematically altering biologically active molecules to study their reactivity without having to build each individual molecule from scratch. Professor Lectka and his research team are determining how loci in a complex molecule interact with a carbon-hydrogen bond-activating agent and using this information to predict and improve the ability to choose a single carbon-hydrogen bond for activation. The carbon-hydrogen bonds in these studies are being converted to carbon-fluorine, carbon-bromine, carbon-oxygen, and carbon-nitrogen bonds, valuable C-H activation transformations in organic synthesis. Professor Lectka is also partnering with the JHU Women in Science and Engineering (WISE) program and the JHU-NSF STEM Achievement in Baltimore Elementary Schools (SABES) program to provide research experiences for local high school students.Site-selective C-H functionalization in complex molecular settings is a current grand challenge motivated by the desire to be able to study and modify natural products and pharmaceutical targets without having to individually prepare each analogue from basic building blocks. Professor Lectka and his research group are investigating a new approach to this problem through the development of hydrogen-atom transfer reagents that can specifically coordinate to a substrate and selectively activate a single carbon-hydrogen bond for C-X bond formation. Simultaneously, this team is also exploring the types of functional groups beyond ketones and enones that can influence the selectivity of the hydrogen-atom transfer reagents and determining the effect of substrate coordination to metal additives. These activities are providing a strong training platform for the professional development of graduate students and research experiences for undergraduate students.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.