Fast Oxidation of Styrene by Oxygen Moleculewith Metal Porphyrin Mn(TPP)OAc Supportedon Alumina or Silica in the Presence of ElectronTransfer Agents in Various Solvents'
The protons on a silica or alu mina su rface can be replaced by manganese( III) porphyrin ca tions, Mn(TPP +). Manganesc(III) porphyrin supported on silica and alumina can activate dioxygen in the presence of additional NaBH4 o r [NBu41rBH41 as an electron source and styrene, affording I-phenyl ethanol and acetophenone in a 4:1 ratio. When oxidation was applied in a mixture of benzene/ethanol, Mn(TPP+) heterogeneous catalyst was desorpted from silica and alumina surface. The oxidation of styrene has also been studied in two phases systems H20/CH2CI2 in the presence of NaBH4 and tetra-n-hutyl amonium bromide as a phase transfer catalys t. Manganese(III) porphyrin remained stable and major product was I - phenyl ethanol, when dichloromethane used in the presence of catalyst supported on alumina, the only product was I - phenyl e thanol.