Polymer-bound schiff-base complex catalyst for effective oxidation of olefins with molecular oxygen

Abstract

Polymer-bound Schiff-base ligand (PS–SalPhe) was prepared from polystyrene-bound salicylaldehyde and phenylalanine, and its complex (PS–SalPhe–M) (M = Co, Mn) was also synthesized. The polymer ligand and its complex were characterized by infrared spectra, small area X-ray photoelectron spectroscopy, and ICP–AES. In the presence of the complex, cyclohexene can be effectively oxidized by molecular oxygen without a reductant. The major products of the reaction are 2-cyclohexen-1-ol (—OH), 2-cyclohexen-1-one (CO), and 2-cyclohexen-1-hydroperoxide (—OOH ), which is different from the typical oxidation of cyclohexene. The mechanism of cyclohexene oxidation is also discussed. Long-chain linear aliphatic olefins, such as 1-octene, 1-decene, 1-dodecene, and 1-tetradecene, can be directly oxidized by molecular oxygen catalyzed by PS–SalPhe–M (M = Mn, Co), which yields the 1,2-epoxy alkane. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1138–1143, 2000