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The kinetic and thermodynamic parameters of the decomposition of isopropylbenzene hydroperoxide in chlorobenzene in the presence of dibenzo-18-crown-6 ether (DB18C6) complexes with CaCl2, SrCl2, and BaCl2 were experimentally obtained. The catalytic activity of the alkaline earth metal compounds decreased in the order SrCl2⋅DB18C6 > CaCl2⋅DB18C6 > BaCl2⋅DB18C6. The formation of intermediates in the metal complex–hydroperoxide system was established kinetically. SrCl2⋅DB18C6 formed the strongest and most ordered structures with isopropylbenzene hydroperoxide, which decomposed at the highest rates. Quantum-chemical modeling confirmed the formation of intermediates. [ABSTRACT FROM AUTHOR]

Highly efficient oxidation of isopropylbenzene mediated by the system of NHPI/Fe(acac)3/Phen has been carried out at temperature as low as 60 °C. Significant improvement of catalysis by NHPI was associated with an enhanced oxidizing ability of Fe(III) tandem with Phen, which caused the intense generation of PINO. Furthermore, NMR observations revealed formation of a hydrogen-bonded NHPI-Phen adduct soluble in acetonitrile and isopropylbenzene. Based on this phenomenon, the system was applicable for the oxidation of solvent-free isopropylbenzene. The promise of the system of NHPI/Fe(acac)3/Phen for the selective synthesis of isopropylbenzene hydroperoxide was demonstrated by oxidation at a low content of Fe(acac)3.