Catalytic autooxidation of p-anisaldehyde and styrene by a cobalt bis-schiff base complex

Abstract

The CoII complex derived from the unsymmetrical bis-Schiff base ligand, 3-[1-[[2-[[(2-hydroxyphenyl)methylene]-amino]ethyl]amino]ethylidene]-6-methyl-2H-pyran-2,4(3H) dione H2(dha, salen), is a catalyst for the autoxidation of aromatic aldehydes. Under ambient condition Co(dha, salen) catalyses the oxidation of p-anisaldehyde to p-anisic acid in quantitative yield (250 turnovers). The presence of Co(dha, salen) also accelerates the co-oxidation of p-anisaldehyde and styrene (88 turnovers). In the co-oxidation process, styrene is selectively converted to styrene oxide as the major product. © 1991 Chapman & Hall.