Enantioselective, Catalytic Trichloromethylation through Visible-Light-Activated Photoredox Catalysis with a Chiral Iridium Complex

An enantioselective, catalytic trichloromethylation of 2-acyl imidazoles and 2-acylpyridines is reported. Several products are formed with enantiomeric excess of >= 99%. In this system, a chiral iridium complex serves a dual function, as a catalytically active chiral Lewis acid and simultaneously as a precursor for an in situ assembled visible-light-triggered photoredox catalyst.