9-Mesityl-10-methylacridinium: an efficient type II and electron-transfer photooxygenation catalyst.
The visible-light irradiation of 9-mesityl-10-methylacridinium perchlorate 1 in the presence of monoalkenes and molecular oxygen leads to typical products of singlet oxygen addition (type II photooxygenation). The molecular probes 1-methylcyclohexene and limonene, respectively, result in hydroperoxide mixtures with a characteristic product pattern. A switch in the oxidative mechanism (electron-transfer photooxygenation) is observed for naphthalene derivatives as electron-rich acceptor molecules, revealing that the 9-mesityl-10-methylacridinium cation serves as a dual sensitizer with the capacity of efficient singlet oxygen formation and electron-transfer reaction. [reaction: see text].
Griesbeck
Axel G
AG
Institute of Organic Chemistry, Greinstr. 4, D-50939 Köln, Germany. griesbeck@uni-koeln.de
Cho
Miyeon
M