SusChEM: Mechanism-based development of new nickel-catalyzed stereospecific ring-contraction and reductive coupling reactions

在这项由化学系化学催化计划资助的项目中，加州大学欧文分校的伊丽莎白·贾沃教授正在开发用于立体选择性合成的富含稀土的镍催化剂。这项研究的更广泛影响包括从地球上丰富的元素中开发出容易获得的催化剂，减少美国对贵金属催化剂的依赖，以及增加可持续性。研究生接受有机和有机金属实验室技术以及机械研究方面的培训。针对妇女和少数族裔研究生和教职员工的辅导和职业发展讲习班被纳入该方案。外展工作吸引了代表性不足的群体，并开发了适用于从中学生到研究生、博士后研究员和初级教员的广泛年龄段的留用技能集。通过与当地学校合作，服务不足的中学生参与加州大学欧文分校的STEM研究环境和机会。由贾沃教授联合创立的LEAPS推广项目，为服务不足、代表性不足的中学生提供了一天的大学体验，包括将他们的课堂作业与化学和物理领域的尖端研究联系起来的动手实验。这个项目的重点是完善对有机镍络合物的两电子反应的机理理解，这是开发用于一系列转化的镍催化剂的关键一步。镍催化剂除了为贵金属钯催化剂提供了一种更可持续的替代品外，还提供了独特的反应模式和优势，特别是在反应通常迟缓的底物和合成新的三元立体中心方面。活性催化剂的特性是通过动力学和结构分析来确定的，包括核磁共振、EPR光谱和X射线结晶学。包括卤代四氢呋喃的还原缩环反应在内的多种新的反应活性正在被开发，以挑战机械假说，并在药物化学中提供取代环丙烷和药效团的实用合成。

AbstractIn this project funded by the Chemical Catalysis program of the Chemistry Division, Professor Elizabeth Jarvo of the University of California, Irvine is developing earth abundant nickel catalysts for stereoselective synthesis. The broader impacts of this research include development of readily available catalysts from earth abundant elements, reducing the US dependence on precious metal catalysts, and increasing sustainability. Graduate students are trained in organic and organometallic laboratory techniques and in mechanistic investigation. Mentoring and career-development workshops that target women and minority graduate students and faculty are integrated into the program. Outreach efforts engage underrepresented groups and develop skills sets for retention across a wide range of ages, from middle school students to graduate students, postdoctoral fellows, and junior faculty. Through partnering with local schools, underserved middle school students participate in STEM research environment and opportunities at UC Irvine. The LEAPS outreach program co-founded by Professor Jarvo provides underserved and underrepresented middle school students with a day at college experience, including hands on experiments that connect their classwork with cutting-edge research in chemistry and physics. This project focuses on refining the mechanistic understanding of two-electron reactions of organonickel complexes, a critical step forward in the development of nickel catalysts for a range of transformations. In addition to providing a more sustainable alternative for precious palladium catalysts, nickel catalysts provide unique reactivity patterns and advantages, particularly in reactions of typically sluggish substrates and for the synthesis of new tertiary stereogenic centers. The identities of active catalysts are being defined using kinetic and structural analysis, including NMR and EPR spectroscopy and X-ray crystallography. New reactivity manifolds, including reductive ring-contractions of halotetrahydrofurans, are being developed to challenge the mechanistic hypotheses and provide practical syntheses of substituted cyclopropanes, pharmacophores in medicinal chemistry.