电化学促进的铱催化烯基 C-H 功能化。
Electrochemistry-Enabled Ir-Catalyzed Vinylic C-H Functionalization.
机构信息
State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 345 Lingling Lu , Shanghai 200032 , China.
Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang , Henan 453007 , China.
出版信息
J Am Chem Soc. 2019 Dec 4;141(48):18970-18976. doi: 10.1021/jacs.9b11915. Epub 2019 Nov 21.
Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.
电化学和有机金属催化的协同作用已成为选择性 C-H 功能化的有力工具，但这种类型的转化迄今为止主要限于芳基 C-H 功能化。在此，我们报告了电化学烯丙基 C-H 官能化与炔烃的丙烯酸。在该反应中，铱催化剂能够实现 C-H/O-H 官能化的炔烃环化，在未分馏的电池中以良好至优异的收率得到α-吡喃酮。初步的机理研究表明，阳极氧化对于从二烯-Ir(I)配合物中释放产物和再生 Ir(III)中间体至关重要，二烯-Ir(I)配合物是配位饱和的、18 电子配合物。重要的是，在没有电流的情况下，在相同的条件下，常见的化学氧化剂如 Ag(I)或 Cu(II)不会产生大量所需的产物。
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