OXYGENATION OF 2,6-DI-TERT-BUTYLPHENOL CATALYZED BY A NEW COBALT(II) COMPLEX [CO(BABP)] - A SALEN ANALOG HAVING HIGHER CATALYTIC ACTIVITY, SELECTIVITY, AND DURABILITY

The deprontated form of the cobalt(II) complex of 6,6′- bis(benzoylamino)-2,2′-bipyridine [Co(babp)] shows excellent catalytic activity in the selective oxygenation of 2,6-di-t-butylphenol (DTBP) to 2,6-di-t-butyl-p-benzoquinone (DTBQ) in the presence of an appropriate base. The durability of [Co(babp)] as an oxygenation catalyst is much higher than that of [Co(salen)] and, furthermore, the reduced catalytic activity of the complex after repeated use can easily be improved to a certain extent by heating at 200°C under reduced pressure.