Abstract :
The ligand-controlled Markovnikov and anti-Markovnikov hydrocarboxylation of styrenes with atmospheric pressure of CO2 at room temperature using dual visible-light-nickel catalysis is developed. In the presence of neocuproine as ligand, the Markovnikov product is obtained exclusively, while employing 1,4-bis(diphenylphosphino)butane (dppb) as the ligand favors the formation of the anti-Markovnikov product. Preliminary mechanistic investigations indicate the generation of a nickel hydride (H-NiII) intermediate, which subsequently adds irreversibly to styrenes.