The mechanistic aspects of iron(III) porphyrin catalyzed oxidation reactions in mixed solvents

摘要

In the iron(III) porphyrin catalyzed oxidation reactions, the formation of various reactive intermediates have been observed to depend upon the nature of the catalyst, the oxidant and the solvent used for the study. The various iron(III) porphyrin catalysts such as F_(20)TPPFeCl, F _(16)TPPFeCl, F_(12)TPPFeCl and F_8TPPFeCl have been used in the present study to understand the effect of solvent system in the activation of the catalysts. As the terminal oxidant t-BuOOH has been used. It has been observed that acetonitrile contaminated with water activates all the catalysts. It has been noted that ～9% of water in acetonitrile is the best solvent system for the activation of all the catalysts. The results obtained have been applied to successfully oxidize cyclohexene and cyclohexane by these oxidizing systems. It has also been observed that CH_3OH mixed with CH_2Cl_2 play a very important role in the activation of catalyst in hydroperoxide oxidizing system. The 33 ± 3% ratio of CH _3OH in CH_2Cl_2 acts as the most suitable solvent system to convert organopalladium compound 1a-c to 2a-c.