Developing Novel Triazole-Ruthenium Carbene Complexes (TA-Ru) for Challenging Olefin Metathesis Transformations

在化学系化学催化项目的支持下，马里兰大学帕克分校的施晓东教授正在开发一类新的催化剂，使具有挑战性的烯烃复分解转化能够发生。 烯烃复分解是一种重要的化学反应，它导致新的碳-碳双键的形成。虽然复分解转化被用于化学，材料和生物研究，但目前的催化剂受到更多需要高温的分子和反应的挑战。相比之下，史教授和他的团队正在开发的新催化剂在更高的温度下显示出显着改善的稳定性。 因此，这些新的催化剂能够合成使用目前的复分解催化剂套件无法获得的新型化学结构。 这些新的分子催化剂将应用于许多问题，不仅将推进基础化学研究，而且还将影响依赖于来自复分解的产品的其他科学领域和行业，例如生物技术和制药行业，化学和材料科学社区/行业。 除了推进复分解在多个科学领域的适用性外，这些研究还将通过为本科生和研究生提供化学合成方面的重要培训，并通过组织面向学生的会议，为下一代科学家的准备提供支持。钌-卡宾复分解催化剂广泛适用于合成化学。 虽然钌催化剂通常显示出良好的反应性和官能团耐受性，但它们随时间分解和/或它们具有热不稳定性。 施晓东教授和他的研究小组发现，容易获得的三唑配体赋予Ru-卡宾催化剂稳定性，从而在应用于烯烃复分解反应时提供新的反应性。这些新的催化剂将被优化用于使用先前报道的催化剂难以进行的转化。为了更好地理解三唑基序的作用，还将进行机理研究。此外，还将开展补充性合成研究，将最初的催化产品转化为对化学生物学、医药和材料化学有用的增值合成目标。该奖项反映了NSF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 Catalysis Program in the Division of Chemistry, Professor Xiaodong Shi of the University of Maryland-College Park is developing a new class of catalysts that enable challenging olefin metathesis transformations to occur. Olefin metathesis is an important chemical reaction that results in the formation of new carbon–carbon double bonds. While metathesis transformations are being employed in chemical, materials, and biological research, current catalysts are challenged by more those molecules and reactions that require high temperatures. In contrast, the new catalysts that are being developed by Professor Shi and his team show significantly improved stability at higher temperature. As a consequence, these new catalysts enable the synthesis of novel chemical structures that are not accessible using the current suite of metathesis catalysts. These new molecular catalysts will be applied to a number of problems and will not only advance fundamental chemical research but will also impact other scientific areas and industries that rely on the products that come from metathesis, e.g. biotech and pharmaceutical industries, the chemical and material science communities/industries. In addition to advancing the applicability of metathesis across several areas of science, these studies will support the preparation of the next generation of scientists by providing undergraduate and graduate students important training in chemical synthesis and through the organization of meetings that are student-oriented.Ruthenium-carbene metathesis catalysts are broadly applicable in synthetic chemistry. While ruthenium catalysts generally show good reactivity and functional group tolerance, they decompose over time and/or they suffer from thermal instability. Professor Xiaodong Shi and his research group have discovered that readily available triazole ligands impart stability on Ru-carbene catalysts and consequently provide novel reactivity when applied to olefin metathesis reactions. These new catalysts will be optimized for transformations that have been difficult to carry out using the previously reported catalysts. In efforts to better understand the role of the triazole motif, mechanistic studies will also be pursued. In addition, complementary synthetic studies will be pursued to convert the initial catalytic products to value-added synthetic targets that will be useful for chemical biology and medicinal and materials 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.