Visible-Light-Mediated Formal Carbene Insertion Reaction: Enantioselective Synthesis of 1,4-Dicarbonyl Compounds Containing All-Carbon Quaternary Stereocenter

We developed an efficient visible-light-mediated formal carbene insertion reaction of 1,3-diketones with diazoesters for the construction of enantioenriched 1,4-dicarbonyl compounds with a quaternary carbon center. Combining visible light and a Brønsted acid catalyst, chiral 1,4-dicarbonyl compounds were achieved in good yields with high enantioselectivities by a photochemical carbene transfer protocol.