Mechanistic insights into the visible-light-driven -arylation of carboxylic acids catalyzed by xanthine-based nickel complexes.

We present a photocatalytic protocol for the -arylation of carboxylic acids using nickel complexes bearing C8-pyridyl xanthines. Our studies suggest that the underlying mechanism operates independently of external photosensitizers. Stoichiometric experiments and crystallographic studies characterize the catalytically relevant Ni complexes.