Of the porphyrin: porphyrin as a catalyst, By the porphyrin: porphyrin embedded with others catalytic system, For the porphyrin: use of a catalyst to synthesise porphyrin.
The role of a porphyrin-based catalytic reactivity have been established via utilizing the porphyrin or modified porphyrin to catalyse an organic chemical transformation; and due to the availability of metal-catalysed reactions to form a new porphyrin building block. In a natural system, cytochrome P-450 enzymes which is a mono-oxygenase family of heme enzyme containing porphyrin moiety catalysed a wide range of biological oxidation reactions. Consequently, synthetic metalloporphyrins were investigated to mimic Cytochrome P-450 which potentially can catalyse selective oxidation reactions. To overcome the limitations of homogeneous catalysis, metalloporphyrin was immobilized onto inorganic support of SBA-15. This heterogeneous catalytic system was further tested for epoxidation of limonene and oxidation of benzyl alcohol. Mimicking the natural existence also drives an extensive discovery of synthetic pathways. It is well-known that the naturally occurring porphyrins exist as a chlorophyll in a photosynthesis process. Therefore, various metal-catalysed synthetic strategies have been used to prepare the alike conjugated porphyrins assembly in monomer, dimer and trimer arrays which in-turn leading to replicate the photosynthetic system. These extended systems can be realized by employing the metal-catalysed Suzuki, Heck and Sonogashira cross-coupling reactions. Overall, catalysis studies have advanced the porphyrin molecular system which was accelerated by natural mimicking approaches.
