Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States.
Department of Chemistry , Columbia University , New York , New York 10027 , United States.
J Am Chem Soc. 2020 Jan 29;142(4):1698-1703. doi: 10.1021/jacs.9b11472. Epub 2020 Jan 14.
The highly regioselective electrophotocatalytic C-H functionalization of ethers is described. These reactions are catalyzed by a trisaminocyclopropenium (TAC) ion at mild electrochemical potential with visible light irradiation. Ethers undergo oxidant-free coupling with isoquinolines, alkenes, alkynes, pyrazoles, and purines with typically high regioselectivity for the less-hindered α-position. The reaction is proposed to operate via hydrogen atom transfer (HAT) from the substrate to the photoexcited TAC radical dication, thus demonstrating a new reactivity mode for this electrophotocatalyst.
本文描述了醚的高区域选择性光电催化 C-H 官能化反应。这些反应在温和的电化学电势下,通过三氨基环丙烯鎓(TAC)离子催化,在可见光照射下进行。醚与异喹啉、烯烃、炔烃、吡唑和嘌呤在通常具有较高区域选择性的条件下发生无氧化剂偶联,生成的产物为位阻较小的α-位。该反应被认为是通过底物向光激发的 TAC 自由基二阳离子的氢原子转移(HAT)进行的,从而证明了这种光电催化剂的一种新反应模式。