Unusual efficiency of a non-heme iron complex as catalyst for the hydroxylation of aromatic compounds by hydrogen peroxide: comparison with iron porphyrins

✍ Scribed by Jean-François Bartoli; François Lambert; Irène Morgenstern-Badarau; Pierrette Battioni; Daniel Mansuy

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 45 KB
• Volume: 5
• Category: Article
• ISSN: 1631-0748
• DOI: 10.1016/s1631-0748(02)01375-9

✦ Synopsis

The non-heme iron complex, Fe(TPAA = tris-[N-(2-pyridylmethyl)-2-aminoethyl]amine)(ClO 4 ) 2 , is a bad catalyst for the epoxidation of alkenes such as cyclooctene, cyclohexene and cis-stilbene and for the hydroxylation of alkanes such as adamantane by H 2 O 2 , when compared to the iron porphyrin Fe[TDCPN 5 P = meso-tetra-(2,6-dichlorophenyl)-βpentanitroporphyrin]Cl. At the opposite, Fe(TPAA)(ClO 4 ) 2 is a much better catalyst for the hydroxylation of arenes by H 2 O 2 ; in its presence, anisole, toluene, ethylbenzene, benzene and chlorobenzene are transformed into the corresponding phenols, with respective yields of 53, 17, 24, 22 and 13% based on H 2 O 2 . Interestingly, in Fe(TPAA)-catalysed oxidations of anisole, toluene and ethylbenzene by H 2 O 2 , hydroxylation of the aromatic ring is by far the major reaction, even when compared to usually favoured reactions such as benzylic oxidation and oxidative demethylation.