Efficient catalytic systems based on cobalt for oxidation of ethylbenzene, cyclohexene and oximes in the presence of N-hydroxyphthalimide

• Co supported on SiO2-Al2O3 used as catalysts using N-hydroxyphthalimide.
• Co catalysts were studied in the oxidation of ethylbenzene to acetophenone.
• Co catalysts were studied in the oxidation of cyclohexene to 2-cyclohexene-1-one.
• Conversions reached to 83 and 75%, and selectivities of 99%.
• Co catalysts for the oxidative deprotection of oximes to carbonyl compounds.

The selective oxidation of ethylbenzene and cyclohexene to acetophenone and 2-cyclohexene-1-one using N-hydroxyphthalimide (NHPI) under oxygen atmosphere in the presence of an SiO2/Al2O3-supported cobalt catalyst occurs with conversions of 83 and 75% and selectivities of 99%. The supported cobalt is also a suitable and efficient catalyst for the oxidative deprotection of oximes to the corresponding carbonyl compounds. The reaction conditions have been optimized considering the effect of various parameters such as reaction time, amount of catalyst, temperature and reusability of the catalyst after several runs. Moreover, some possible mechanisms for the oxidation of ethylbenzene, cyclohexene and oximes have been proposed.

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