Abstract The biomimetic oxidation of caffeine with hydrogen peroxide using metalloporphyrins as catalysts, which are known to be good biomimetic models of cytochrome P450 enzymes, is investigated. The two manganese porphyrins tested, chloro [5, 10, 15, 20-tetrakis (2, 6-dichlorophenyl) porphyrinato] manganese (III),[Mn (TDCPP) Cl], and chloro [5, 10, 15, 20-tetrakis (pentafluorophenyl) porphyrinato] manganese (III),[Mn ( ...