Homogeneous m-CPBA-oxidation of anthracene by electron-withdrawing metalloporphyrins in different reaction conditions Original Research Article

Anthracene was oxidized to anthrone, oxanthrone and anthraquinone with metachloroperbenzoic acid (m-CPBA) as oxidant and iron and manganese porphyrins (FeF20TPPCl, MnF20TPPCl, FeCl8TPPCl and MnCl8TPPCl) as catalysts. The catalytic oxidation yields were dependent on the catalyst and solvent. In the presence of FeF20TPPCl, in an acetonitrile solution, anthraquinone was formed in 60% yield with 100% selectivity. In the presence of water, CH3CN:H2O (4:1) with FeF20TPPCl catalyst, anthrone, oxanthrone and anthraquinone were formed with respective yields of 8.4%, 84.4% and 37.6%, based on m-CPBA oxidant. When the CH3CN:H2O ratio changed from 4:1 to 49:1, the yields of anthrone and anthraquinone increased to 40.0% and 68.0%, respectively whereas the yield of oxanthrone decreased to 16.1%. Moreover, the effect of axial ligand and oxidant, as well as the effect of catalysts in the oxidation of anthracene, anthrone and oxanthrone were also investigated.