부산대학교 도서관

The catalytic reactivity of an iron(ii) complex [(TPA)FeII(CH3CN)2]2+ (1) (TPA = tris(2-pyridylmethyl)amine) towards oxygenative aromatic C–C bond cleavage of catechol and 2-aminophenol is presented. Complex 1 exhibits catalytic and regioselective C–C bond cleavage of 3,5-di-tert-butylcatechol (H2DBC) to form intradiol products, whereas it catalyzes extradiol-type C–C bond cleavage of 2-amino-4,6-di-tert-butylphenol (H2AP). The catalytic reactions are found to be pH-dependent and the complex exhibits maximum turnovers at pH 5 in acetonitrile–phthalate buffer. An iron(iii)–catecholate complex [(TPA)FeIII(DBC)]+ (2) is formed in the ring cleavage of catechol. In the extradiol-type cleavage of H2AP, an iron(iii)–2-iminobenzosemiquinonate complex [(TPA)FeIII(ISQ)]2+ (3) (ISQ = 4,6-di-tert-butyl-2-iminobenzosemiquinonate radical anion) is observed in the reaction pathway. This work shows the importance of the nature of ‘redox non-innocent’ substrates in governing the mode of ring fission reactivity. [ABSTRACT FROM AUTHOR]