Cobalt-Catalyzed C-H Functionalizations by Imidate Assistance with Aryl and Alkyl Chlorides

A catalytic system comprising the inexpensive cobalt(II) acetylacetonate [Co(acac)(2)] and an N-heterocyclic carbene (NHC) ligand enabled versatile C-H arylations by oxazoline assistance. The broadly applicable, low-valent cobalt catalyst displayed a wide substrate scope, and even proved applicable to challenging C-H alkylations with beta-hydrogen-containing primary and secondary alkyl chlorides. The power of the cobalt-catalyzed C-H arylation protocol was among others reflected by facile C-H activation at a room temperature of 23 degrees C, and efficient late-stage diversification, providing access to bioactive biaryls.