| 초록 |
Photoredox catalysis exploits excited-state electron transfer to initiate one-electron redox chemistries. The excited-state catalysis provides thermicity much greater than that attainable by the thermal catalysis, enabling the facile radical generation. My group identified unique catalysis mechanisms of fine chemicals syntheses. Recent, notable achievements involve the photoredox catalytic borylation of aryl halides. Different from conventional methods relying on Pd catalysts, the borylation reaction can be performed at room temperature. The conversion is also tolerant to the presence of various functional groups. We found that an excited-state radical ion serves as the key catalytic species. This species can reductively cleave the robust C-X bond of haloarene to yield a benzene radical intermediate. Our spectroscopic and electrochemical experiments provided direct evidence that activation of the catalyst occurs through sequential absorption of two photons. |
