Conjugate Chiral Carbon Dots for Scalable Asymmetric Photocatalysis in Flow

Abstract Carbon dots (CDs) have emerged as scalable, metal-free photocatalysts, but their use as conjugate organo-photocatalysts for enantioselective chemistry remains unexplored. Here, we covalently anchor a chiral imidazolidinone organocatalyst to amorphous, citric acid-derived CDs, giving a colloidal conjugate that acts as both photosensitizer and enantiodetermining component. This chiral CD material promotes the asymmetric radical α-alkylation of aldehydes in up to 84% yield and 93% e.e. Its semihomogeneous nature enables catalyst recovery by precipitation and reuse over five cycles with only minor loss in yield and e.e. The well-dispersed conjugate is also compatible with continuous photoflow, where Bayesian optimization in only 10 experiments enabled a gram-scale reaction in 80% yield and 91% e.e. This work establishes chiral conjugate CDs as a practical, recoverable platform for sustainable asymmetric photocatalysis.