Aldehyde Deformylation and Catalytic C–H Activation Resulting from a Shared Cobalt(II) Precursor

The tetradentate ligand N,N′-dibenzyl-N,N′-bis­(2-pyridylmethyl)-1,2-cyclohexanediamine (bbpc) was used to prepare cobalt­(II) diacetonitrilo and cobalt­(III) peroxo complexes, the latter of which was structurally characterized. The cobalt­(III) peroxo compound forms from reactions between the cobalt­(II) complex, hydrogen peroxide, and a base, and it stoichiometrically reacts with aldehydes to yield mixtures of alkenes and ketones. The cobalt­(II) precursor is capable of catalyzing the activation of weak C–H bonds by either iodosobenzene or m-chloroperbenzoic acid. This chemistry differs from most previously characterized cobalt-mediated C–H activation in that (1) it is catalytic, rather than stoichiometric, with respect to the cobalt and (2) it does not need a second Lewis acid metal ion in order to proceed.