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

使用 CuII/CuIII 氧化还原催化剂进行电驱动 C-H 官能化

• 批准号: 10629279
• 负责人: Shiyu Zhang
• 金额: $ 31.34万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629279
• 关键词: Address; Alcohols; Alkenes; Amides; Amines; Carbon; Cells; Chemicals; Chemistry; Complex; Coupled; Development; Diffuse; Electrochemistry; Electrodes; Electrolyses; Electron Transport; Electrons; Environment; Ethers; Event; Fluorides; Fluorine; Friends; Goals; Health; Human; Hydrogen; Hydrogen Bonding; Kinetics; Ligands; Liquid substance; Mediating; Mediator; Medicine; Metals; Methods; Organic Synthesis; Oxidants; Oxidation-Reduction; Positioning Attribute; Process; Property; Reaction; Reagent; Salts; Scientist; Side; Site; Source; Sulfhydryl Compounds; Surface; Temperature; Training; Work; catalyst; cold temperature; cost; energy efficiency; enol; enolate; improved; innovation; oxidation; programs; skills; success; voltage; wasting

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.

项目概要 该提案旨在开发利用电能进行 C-H 官能化重组的新合成方法。 行动。电驱动的 C-H 官能化非常重要，因为它消除了超化学计量的 强氧化剂通常导致高成本和差的位点选择性。拟议工作的创新点 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 亲核试剂。这些 CuIII-Nu 配合物具有反向配体场，其中 LUMO 位于配体上 Cu 中心。因此，电化学生成的 CuIII-Nu 络合物可以作为 Nu 的驯化来源。 自由基以实现氢原子转移和自由基拦截。我们的方法分离双电子 C-H 函数 化过程转化为两个具有快速电极动力学的并行单电子氧化事件。因此， CuII/CuIII 介导的 C-H 官能化发生在比传统的电势低得多的电位（0.5-2 V） 电化学C-H功能化方法，显着提高能量效率和选择性。预习- 初步结果表明，C(sp3)-H 键与多种简单亲核试剂发生选择性官能化， 否则与传统 C-H 官能化反应中通常使用的化学氧化剂不相容， 例如，已知氟化物会导致多种氧化剂分解，因此可以直接使用 作为我们电化学条件下的 F 源。唯一的副产物是易于管理的金属盐， 显着降低成本。此外，所有 CuIII-Nu 中间体都可以在低温下分离和表征。 性质揭示基本性质和反应性，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。该信息用于选择合适的电 化学/化学条件，如电压、电流、温度、配体，合理提高反应效率 效率和选择性。