Chemoselective and ligand‐free aerobic oxidation of benzylic alcohols to carbonyl compounds using alumina‐supported mesoporous nickel nanoparticle as an efficient recyclable heterogeneous catalyst
Asit Kumar Das, Sneha Nandy, Sanjay Bhar
Abstract
An economically efficient and operationally simple ligand‐free protocol for the chemoselective oxidation of benzylic alcohols to carbonyl compounds has been developed using alumina‐supported nickel nanoparticles as a stable recyclable heterogeneous catalyst along with potassium tert ‐butoxide in the presence of aerial oxygen as an eco‐friendly oxidant. The aliphatic alcohols remained unaffected under the present condition. Excellent chemoselectivity has also been demonstrated through intermolecular and intramolecular competition experiments. This protocol accommodates a diverse range of substituents with the tolerance of various sensitive moieties during the reaction. The catalyst could be recovered by filtration and reused consecutively without any significant loss in the catalytic activity. Moreover, the heterogeneity of the catalyst has also been established by the “hot filtration method (Sheldon's test)”.