Transition Metal Catalysis of Electrocyclic Reactions

在化学系化学催化计划的支持下，加州大学圣地亚哥分校的约瑟夫·奥康纳教授将研究将含有多个碳-碳双键的现成无环有机化合物转化为高价值环状化合物的新方法。这将通过设计新的有机金属催化剂来实现，这种催化剂可以高度控制产品分子的三维结构。有机金属催化剂是一种含碳和金属的物质，当加入微量的反应混合物时，可以加快原料向产品的转化。催化剂允许较低的反应温度，从而最大限度地减少能量输入和相关温室气体的产生。此外，催化剂还可防止不受欢迎的副产品的形成及其对环境的负面影响。控制拟议中间体生成的新方法将促进我们对碳氢化合物化学这一相对未被探索但重要的领域的理解。所提出的研究将有助于未来在生态友好型制备具有有用性质的有机分子方面的进展。学生，包括妇女、残疾人和代表不足的少数群体的人，将接受跨越机械、合成、有机金属和计算化学的多学科培训，从而为他们未来在工业和学术界的独立科学贡献做好准备。在获奖的情况下，奥康纳研究小组将研究催化共轭三烯电环化的新方法。预计这些研究将为开发新的催化剂奠定基础，这些催化剂可以促进具有挑战性的反应，这些反应涉及高度离域的非极性过渡态结构。催化剂设计的创新包括具有三个可访问的金属配位的表面阵列的金属催化剂，用于金属与三个pi键的同时相互作用。低温光谱学、X射线结晶学和计算研究将被用来揭示六齿配位如何扰乱多烯结构并诱导不旋转三烯环闭合。通过使用手性辅助配体，对映体选择性电环化将成为靶向。对金属催化的电环化反应的研究将开启合成复杂生物活性化合物、设计性配体和新材料的新的逆向合成方法。这些新的电环化反应的范围和局限性将被详细研究。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。

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.