Synergistic Activation of Amides and Hydrocarbons for Direct C(sp )-H Acylation Enabled by Metallaphotoredox Catalysis.

The utilizations of omnipresent, thermodynamically stable amides and aliphatic C(sp )-H bonds for various functionalizations are ongoing challenges in catalysis. In particular, the direct coupling between the two functional groups has not been realized. Here, we report the synergistic activation of the two challenging bonds, the amide C-N and unactivated aliphatic C(sp )-H, via metallaphotoredox catalysis to directly acylate aliphatic C-H bonds utilizing amides as stable and readily accessible acyl surrogates.

Peroxocobalt(iii) species activates nitriles via a superoxocobalt(ii) diradical state.

The dioxygenation of nitriles by [CoIII(TBDAP)(O2)]+ (TBDAP = N,N-di-tert-butyl-2,11-diaza[3.3](2,6)-pyridinophane) is investigated using DFT-calculations. The mechanism proposed previously based on experimental observations, which invoked an outer-sphere cycloaddition, was found to be unreasonable.