Transition Metal Catalysis of Electrocyclic Reactions

在化学系化学催化项目的支持下，加州大学圣地亚哥分校的Joseph奥康纳教授将研究新的方法，将容易获得的含有多个碳碳双键的无环有机化合物转化为高价值的环状化合物。这将通过设计新的有机金属催化剂来实现，该催化剂提供对产物分子的三维结构的高度控制。有机物催化剂是含碳和金属的物质，当以痕量添加到反应混合物中时，加速起始材料向产物的转化。催化剂允许较低的反应温度，从而最大限度地减少能源投入和相关的温室气体的产生。此外，催化剂防止形成不期望的副产物及其相关的负面环境影响。新的方法控制产生拟议的中间体将推进我们的理解相对未开发的，但重要的碳氢化合物化学领域。拟议的研究将有助于未来在生态友好的制备具有有用特性的有机分子的进展。学生，包括妇女，残疾人，以及来自少数民族的人，将接受跨学科的培训，涵盖机械，合成，有机金属和计算化学，从而定位他们未来在工业界和学术界的独立科学贡献。根据奖项，奥康纳研究小组将研究新的方法来催化共轭三烯的电环化。预计这些研究将为开发新的催化剂奠定基础，这些催化剂有助于涉及高度离域的非极性过渡态结构的具有挑战性的反应。催化剂设计创新包括具有三个可接近的金属配位位点的表面阵列的金属催化剂，用于金属与三个π键的同时相互作用。低温光谱，X射线晶体学和计算研究将被用来揭示如何hexadentate协调扰动多烯结构，并诱导对旋三烯环闭合。通过使用手性辅助配体，将靶向对映选择性电环化。对金属催化电环化的研究将为复杂的生物活性化合物、设计配体和新材料的合成开辟新的逆合成方法。该奖项反映了NSF的法定使命，并被认为值得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的支持。

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Joseph O’Connor of the University of California, San Diego will study new ways to convert readily available acyclic organic compounds that contain multiple carbon-carbon double bonds into high-value cyclic compounds. This will be achieved by the design of new organometallic catalysts that provide a high degree of control over the three-dimensional structure of the product molecules. Organometallic catalysts are carbon- and metal-containing substances that, when added in trace amounts to a reaction mixture, speed up the conversion of starting materials to products. Catalysts permit lower reaction temperatures, thereby minimizing energy input and the associated production of green-house gases. In addition, catalysts prevent the formation of undesired byproducts and their associated negative environmental impacts. Novel approaches for the controlled generation of proposed intermediates will advance our understanding of a relatively unexplored but important area of hydrocarbon chemistry. The proposed research will contribute to future advances in the eco-friendly preparation of organic molecules with useful properties. Students, including women, persons with disabilities, and persons from underrepresented minority groups, will receive will receive multidisciplinary training that spans mechanistic, synthetic, organometallic, and computational chemistry, thereby positioning them for future independent scientific contributions in both industry and academia.Under with award, the O’Connor research group will study new ways to catalyze the electrocyclization of conjugated trienes. It is anticipated that these studies will lay a foundation for the development of new catalysts that facilitate challenging reactions that involve highly delocalized, nonpolar transition-state structures. The catalyst design innovations include metal catalysts with a facial array of three accessible metal coordination sites for the simultaneous interaction of the metal with three pi-bonds. Low temperature spectroscopy, X-ray crystallography, and computational studies will be utilized to reveal how hexadentate coordination perturbs polyene structures and induces disrotatory triene ring closure. By employing a chiral ancillary ligand, enantioselective electrocyclization will be targeted. Studies into metal-catalyzed electrocyclization will unlock new retro-synthetic approaches for the synthesis of complex biologically active compounds, designer ligands, and new materials. The scope and limitations of these new electrocyclization reactions will be studied in detail.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.