Green synthesis of hydratropic aldehyde from α-methylstyrene catalyzed by Al2O3-supported metal phthalocyanines

Abstract

This report presents a study of synthesis of hydratropic aldehyde from α-methylstyrene employing Al2O3-supported metal phthalocyanines as catalyst, molecular oxygen as oxidant and isobutyraldehyde as co-oxidant. The catalytic system was applied in the synthesis of hydratropic aldehyde for the first time. Under optimal conditions, the conversion of α-methylstyrene reached 99%, whereas the selectivity of hydratropic aldehyde reached 85.14%. Possible reaction mechanism and the effects of different factors on oxidation reaction were investigated. Aluminum oxide-supported metal (M = Co, Ni, and Fe) phthalocyanine catalysts (MPc/Al2O3) were prepared using the “ship-in-a-bottle” method by synthesizing metallophthalocyanines in support holes. Obtained catalysts were characterized by N2 adsorption, Brunauer-Emmett-Teller surface area (BET), inductively-coupled plasma atomic emission spectrometry (ICP-AES), IR, UV-Visible (UV-Vis), and X-ray diffraction (XRD).

Keywords

• α-methylstyrene
• aluminum oxide-supported metal phthalocyanine
• catalytic oxidation
• hydratropic aldehyde
• molecular oxygen