Catalytic autooxidation ofp-anisaldehyde and styrene by a cobaltbis-schiff base complex

Summary The Co^II complex derived from the unsymmetricalbis-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 ofp-anisaldehyde top-anisic acid in quantitative yield (250 turnovers). The presence of Co(dha, salen) also accelerates the co-oxidation ofp-anisaldehyde and styrene (88 turnovers). In the co-oxidation process, styrene is selectively converted to styrene oxide as the major product.