Photocatalytic Cycloadditions Enabled by a Lithium Perchlorate/Nitromethane Electrolyte Solution

Abstract

Photocatalytic cycloadditions involving carbon–carbon bond formation in the absence of an external sensitizer are described. The use of a lithium perchlorate/nitromethane electrolyte solution exhibiting remarkable Lewis acidity is the key for the successful transformations. According to the UV/Vis measurements, an electron donor–acceptor complex did not form and nitromethane was expected to function as the initial sensitizer for the reactions. Although the mechanisms are still under debate, both electron‐ and energy‐transfer processes could be involved, both of which are triggered by excited nitromethane in combination with molecular oxygen.

Probing Intramolecular Electron Transfer in Redox Tag Processes

“…We have been developing oxidative SET-triggered radical cation reactions by electrocatalysis and photocatalysis in lithium perchlorate (LiClO 4 )/nitromethane (CH 3 NO 2 ) solution . Carbon–carbon bond formation involving an alkenyl radical cation is facilitated by the LiClO 4 /CH 3 NO 2 solution, where the trapping thereof by unactivated alkenes is made possible.…”

Arene C–H Amination with N-Heteroarenes by Catalytic DDQ Photocatalysis

“…In the current DDQ photocatalytic system, we also obtained very similar UV–vis spectra, suggesting that DDQ was regenerated from DDQH 2 even in the absence of TBN (Figure S1). Although the terminal oxidant remains unclear, adventitious O 2 and/or CH 3 NO 2 may have the potential to reactivate DDQH 2 to DDQ under UV light irradiation conditions.…”