Thioxanthone‐Based Hyper‐Crosslinked Polymers for Visible‐Light‐Driven Asymmetric α‐Hydroxylation With O ₂

Herein, a series of hyper‐crosslinked polymers (HCPs) photocatalysts are synthesized based on thioxanthone via a typical Friedel–Crafts alkylation reaction. Through the synergistic catalysis of these HCP photocatalysts and chiral metal complexes, a visible‐light‐induced asymmetric α‐hydroxylation of β‐keto esters is developed employing environmentally benign molecular oxygen as the oxygen source with good to excellent yields and enantioselectivities. The heterogeneous HCPs photocatalyst offers high efficiency, broad functional group tolerance, easy recyclability, robust stability, and consistent reusable activity. The promising potential for industrial application is demonstrated by successful gram‐scale catalytic cycles.