A novel, green 1-glycyl-3-methyl imidazolium chloride–copper(II) complex catalyzed CH oxidation of alkyl benzene and cyclohexane

Cu(ii) Schiff base complex intercalated into layered double hydroxide for selective oxidation of ethylbenzene under solvent-free conditions

A new heterogeneous catalyst was prepared by intercalation of NNOO donor Cu(ii) Schiff base complex derived from 2-hydroxy-1-naphthaldehyde and 4-amino benzoic acid into Zn–Al layered double hydroxide {LDH-[NAPABA–Cu(ii)]}. Synthesized catalyst was characterized by Inductively coupled plasma atomic emission spectroscopy, energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction, Transmission electron microscopy, BET surface area, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, electron paramagnetic resonance spectroscopy and diffuse reflectance UV-visible spectroscopy. The catalytic performance of LDH-[NAPABA–Cu(ii)] was studied for the liquid phase solvent-free oxidation of ethylbenzene at 393 K, using tert-butylhydroperoxide as an oxidant. In oxidation reaction ethylbenzene was oxidized to acetophenone, benzaldehyde and benzoic acid. The major product was acetophenone. A maximum, 80.54% conversion of ethylbenzene was observed after 7 hours. The catalyst was recycled seven times without significant loss of catalytic activity.

A heterogeneous catalytic system, LDH-[NAPABA–Cu(ii)]/TBHP gave maximum 80.54% conversion and 99.60% selectivity for acetophenone in oxidation of ethylbenzene and catalyst can be reused for seven cycles.

Catalytic Oxidation of Alkyl Benzene

Oxidation of benzylic C-H bonds of alkyl benzene for the synthesis of corresponding carbonyl compounds is a very important reaction for both commercial manufacturing and basic research. This paper reviews various kinds of catalysts involved in the oxidation of alkyl aromatic and their activity in various conditions and probable mechanism of action where applicable. The rate of conversion of alkyl aromatic and per cent of the yield of the corresponding products for each catalyst has been included.