Enantioselective photooxygenation of β-dicarbonyl compounds in batch and flow photomicroreactors.

A series of C-2' modified cinchonine-derived phase-transfer catalysts were synthesized and used in the enantioselective photo-organocatalytic aerobic oxidation of β-dicarbonyl compounds with excellent yields (up to 97%) and high enantioselectivities (up to 90% ee). Furthermore, the reaction was carried out in a flow photomicroreactor, in which the heterogeneous gas-liquid-liquid asymmetric photocatalytic oxidation reaction was performed affording good yields (up to 97%) and enantioselectivities (up to 86% ee) within 0.89 min.