Iridium-Catalyzed, Intramolecular Cyclization of Allylic Alcohols for Quaternary Center Synthesis

Melissa Ramirez被授予21财年数学和物理科学提升博士后研究奖学金(NSF MPS-Ascend)，以开展与加州理工大学化学专业代表不足的群体扩大参与相关的研究和活动。由Melissa Ramirez执行的题为Iridium催化的烯丙醇分子内环化用于四元中心合成的项目将在指导科学家Brian M.Stoltz的指导下进行。这个项目得到了多学科活动办公室和数学和物理科学化学司的支持。这个项目支持发展一种在Ir催化下，碘介导的烯丙醇分子内环化反应，它将作为烯醇合成子来生成含有环己酮和环庚烯酮的四元中心构建块。对反应机理和关键的对映体确定步骤的计算分析将指导手性铱催化剂的设计，以开发反应的对映选择性变体，并将在实验中进行测试和开发。这项工作将为未来新型配体的设计建立指导原则，使高通量实验筛选的效率成为可能，并通过使用Ir催化和高价碘化学对烯丙醇进行非极化官能化来解决长期存在的形成邻近立体中心的挑战。Ramirez博士将通过指导和参与加州理工学院研究生教育联盟和教授项目，继续努力扩大参与范围。该奖项反映了NSF的法定使命，并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，被认为值得支持。

Melissa Ramirez is awarded a FY21 Mathematical and Physical Sciences Ascending Postdoctoral Research (NSF MPS-Ascend) Fellowship to conduct a program of research and activities related to broadening participation by groups underrepresented in Chemistry at Cal Tech. The project being performed by Melissa Ramirez, entitled Iridium-Catalyzed, Intramolecular Cyclization of Allylic Alcohols for Quaternary Center Synthesis, is to be conducted under the guidance of mentoring scientist Brian M. Stoltz. This project is supported by the Office of Multidisciplinary Activities and the Chemistry Division in the Mathematical and Physical Sciences.This project supports the development of an iridium-catalyzed, iodine-mediated intramolecular cyclization of allylic alcohols, which would serve as enolate synthons to generate quaternary center-containing cyclohexenone and cycloheptenone building blocks. Computational analysis of the reaction mechanism and the key enantiodetermining step will guide the design of a chiral iridium catalyst for the development of an enantioselective variant of the reaction, which will be tested and developed experimentally. This work will establish guiding principles for the future design of novel ligands, enabling efficiency in high throughput experimental screening and providing a solution to the long-standing challenge of vicinal stereocenter formation via umpolung functionalization of allylic alcohols using iridium catalysis and hypervalent iodine chemistry. Dr. Ramirez will continue efforts in broadening participation through mentoring and by participating the Alliances for Graduate Education and the Professorate program at Caltech.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.