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: 10419770
• 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/10419770
• 关键词: Address; Alcohols; Alkenes; Amides; Amines; Anodes; Carbon; Cells; Chemicals; Chemistry; Complex; Coupled; Development; Diffuse; Electrochemistry; Electrodes; Electrolyses; Electron Transport; Electrons; Ethers; Event; Fluorides; Fluorine; Goals; Health; Human; Hydrogen; Hydrogen Bonding; Intercept; Kinetics; Ligands; Liquid substance; Mediating; Mediator of activation protein; Metals; Methods; Organic Synthesis; Oxidants; Oxidation-Reduction; Oxides; Positioning Attribute; Process; Property; Reaction; Reagent; Salts; Scientist; Side; Site; Source; Sulfhydryl Compounds; Surface; Temperature; Training; Work; base; catalyst; cold temperature; cost; 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.

项目摘要 该提案旨在开发新的合成方法，利用电能进行C-H官能化再合成， 行动电驱动的C-H官能化是重要的，因为它消除了超化学计量的C-H官能化。 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 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络合物的特征在于反转的配体场，其中LUMO反而驻留在配体上 在Cu中心。因此，电化学产生的CuIII-Nu络合物可以用作Nu的驯服来源 自由基，使氢原子转移和自由基拦截。我们的方法分离了双电子C-H功能， 在快速电极动力学下，电离过程分为两个平行的单电子氧化事件。因此，在本发明中， CuII/CuIII介导的C-H官能化发生在比传统的C-H官能化低得多的电位（0.5-2 V 电化学C-H官能化方法，显著提高能量效率和选择性。- 初步结果表明，C（sp3）-H键的选择性官能化与广泛的简单亲核试剂， 否则与通常用于常规C-H官能化反应的化学氧化剂不相容， 例如，可以直接使用已知会导致多种氧化剂分解的氟化物 在我们的电化学条件下作为F源。仅有的副产物是易于处理的金属盐， 大大降低了成本。此外，所有的CuIII-Nu中间体都可以在低温下分离和表征。 揭示基本性质和反应性的性质，例如，氧化还原电位，氢原子转移，自由基 捕获、烯烃加成和其它非生产性反应性。该信息用于选择合适的电- 化学/化学条件，例如，电压、电流、温度、配体等因素，合理提高反应效率。 科学性和选择性。