Metal-free oxygenation of cyclohexane with oxygen catalyzed by 9-mesityl-10-methylacridinium and hydrogen chloride under visible light irradiation.

Photooxygenation of cyclohexane by O(2) occurs efficiently under visible-light irradiation of an O(2)-saturated acetonitrile solution containing 9-mesityl-10-methylacridinium ions (Acr(+)-Mes) and HCl to yield cyclohexanone, cyclohexanol and hydrogen peroxide. The photocatalytic reaction is initiated by electron transfer from Cl(-) to the mesitylene radical cation moiety. This journal is © The Royal Society of Chemistry 2011