Electrically Driven C-H Functionalization with CuII/CuIII Redox Catalysts

项目摘要 本建议旨在开发利用电能进行C-H官能化再合成的新方法。 行为。电驱动的C-H官能化意义重大，因为它消除了超化学计量的 强氧化剂，往往导致成本高和现场选择性差。拟议工作的创新之处 是CuIII/CuII-Nu氧化还原催化剂的开发，其中Nu代表各种碳和杂原子基催化剂 亲核主义者。这些CuIII-Nu络合物具有反转的配位场，其中LUMO驻留在配体上 铜中心的位置。因此，电化学生成的CuIII-Nu络合物可以作为Nu的驯化来源 能够实现氢原子转移和自由基拦截的自由基。我们的方法分离了两个电子的C-H基团。 量子化过程分为两个平行的单电子氧化事件，具有快速的电极动力学。结果, CuII/CuIII介导的C-H官能化发生在比传统C-H官能化更低的电位(0.5-2V 电化学C-H官能化方法，显著提高能源效率和选择性。初审- 初步结果表明，C(SP3)-H键与范围广泛的简单亲核试剂选择性官能化 在其他方面与常规C-H官能化反应中通常使用的化学氧化剂不兼容， 例如，可以直接使用氟化物，这种已知会导致多种氧化剂分解的物质 在我们的电化学条件下作为氟源。唯一的副产品是易于管理的金属盐， 大大降低了成本。此外，所有CuIII-Nu中间体都可以在较低的温度下分离和表征。 揭示基本性质和反应性的温度，例如，氧化还原电位、氢原子转移、自由基 捕获、烯烃加成和其他非生产性反应性。该信息用于选择合适的电子产品 化学/化学条件，如电压、电流、温度、配体，以合理地提高反应效率。 有效性和选择性。

Project Summary This proposal aims to develop new synthetic methods that utilize electrical energy for C-H functionalization re- actions. Electrically driven C-H functionalization is significant since it eliminates superstoichiometric amounts of strong oxidants that often contribute to high costs and poor site selectivity. The innovation of the proposed work is the development of CuIII/CuII-Nu redox catalysts, where Nu represents various carbon and heteroatom-based nucleophiles. These CuIII-Nu complexes feature inverted ligand fields, where LUMO resides on the ligand instead of the Cu center. Therefore, electrochemically generated CuIII-Nu complexes can serve as tamed sources of Nu radical to enable hydrogen atom transfer and radical interception. Our method separates two-electron C-H func- tionalization processes into two parallel, single-electron oxidation events with fast electrode kinetics. As a result, the CuII/CuIII mediated C-H functionalization occurs at much lower potentials (by 0.5-2 V) than those of traditional electrochemical C-H functionalization methods, significantly improving energy efficiency and selectivity. Prelim- inary result shows selective functionalization of C(sp3)-H bonds with a wide range of simple nucleophiles that are otherwise incompatible with chemical oxidants typically used in conventional C-H functionalization reactions, For example, fluoride, which is known to cause decomposition of a wide range of oxidants, can be directly used as F source under our electrochemical condition. The only side products are readily manageable metal salts, significantly reducing the cost. Moreover, all CuIII-Nu intermediate can be isolated and characterized at low tem- peratures to reveal fundamental properties and reactivity, e.g., redox potentials, hydrogen atom transfer, radical capture, alkene addition, and other unproductive reactivity. This information is used to select suitable electro- chemical/chemical conditions, e.g., voltage, current, temperature, ligand, to rationally improve the reaction effi- ciency and selectivity.