Alkane hydroxylation by m-CPBA catalyzed by Co(II)-complexes

• Exploring catalytic mechanism of alkane hydroxylation by m-chloroperbenzoic acid. • Cobalt(II) complexes of N4-tirpodal tetradentate ligands work as efficient catalyst. • Involvement of cobalt-oxyl type intermediate is demonstrated. • Co(II) complex is a better catalyst compare to Fe(II), Ni(II), and Cu(II) complexes. Catalytic activities of the cobalt(II) complexes supported by tripodal N 4 -tetradentate ligands have been examined in the alkane hydroxylation reaction by m -CPBA ( m -chloroperbenzoic acid). Detailed product analysis data have indicated that hydrogen atom abstraction (HAA) from the alkane substrates is a key step in the hydroxylation reaction, where not only the aroyloxy radical intermediate (ArC(O)O•; Ar = m -chlorophenyl)) derived from m -CPBA via O–O bond homolysis but also a Co–O• type intermediate is involved as a reactive oxidant. Significant effects of the supporting ligands and the metal ions (Fe II , Ni II , and Cu II ) support this mechanism.