5,10,15,20-Tetrakisaryl- and 2,3,7,8,12,13,17, 18-octahalogeno-5,10,15,20-tetrakisarylporphyrins and their metal complexes as catalysts in hypochlorite epoxidations

Abstract

Improvements are described to the synthesis of the catalytically important 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin 1(R = H) and [2,3,7,8,12,13,17,18-octachloro-tetrakis(2,6-dichlorophenyl)porphyrinato]manganese(III)3(R = Cl) which enable large-scale preparation of such compounds to be carried out easily. A comparative study of the catalytic performance of the manganese complexes of these two porphyrins proved that, contrary to earlier expectations, the manganese complex of 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin is the most stable and efficient catalyst for epoxidation when using sodium hypochlorite as oxidant. With [2,3,7,8,12,13,17,18-octachloro-tetrakis(2,6-dichlorophenyl)porphyrinato]manganese(III)3, chlorinated products tend to be formed and these can be the dominant products for some substrates.