Trans-Dioxidomolybdenum(VI) Porphyrins and their Catalytic Activity Mimicking Oxidative Bromination

Synthesis of trans-dioxidomolybdenum(VI)-meso-tetraphenylporphyrin (trans-[(MoO2)-O-VI(TPP)], 1) and trans-dioxidomolybdenum(VI)-meso-tetra(p-chlorophenyl)porphyrin (trans-[(MoO2)-O-VI(TCPP)], 2) by reacting the corresponding free-base porphyrins with Mo(CO)(6) in 1,2,4-trichlorobenzene at 190 degrees C has been reported. These are the second examples in the literature where molybdenum-porphyrins have trans-[MoVIO2] group, identified by single crystal X-ray study. Both complexes have been utilized as functional model of haloperoxidases for the oxidative bromination of various phenol derivatives using KBr, H2O2 and HClO4 as green brominating reagents in aqueous medium. These complexes displayed very high TOF values (up to 16.2 s(-1 )for catalyst 2) representing excellent catalytic activity. To the best of our knowledge, this is the first report presenting trans-dioxidomolybdenum(VI) based porphyrin as haloperoxidases mimicking oxidative bromination of various phenol derivatives.