Heteroatom‐Engineered Linear Conjugated Polymers for Photocatalytic O 2 Reduction and Biocatalytic sp 3 C─H Oxyfunctionalization

ABSTRACT Visible light‐driven biocatalytic oxyfunctionalization using water and oxygen as feedstocks represents a key strategy for sustainable and environmentally friendly solar‐to‐chemical conversion. Here, we report an azine‐tailored linear conjugated polymer for in situ oxygen reduction reaction (ORR) for hydrogen peroxide (H 2 O 2 ) generation and biocatalytic oxyfunctionalization of inert C─H bonds. The in situ generated H 2 O 2 subsequently activates the unspecific peroxygenase from Agrocybe aegerita ( rAae UPO) that catalyzes the enantioselective sp 3 oxyfunctionalization. Experimental and theoretical investigation revealed that poly(1,4‐diethynylbenzene‐alt‐2,5‐pyrazine) (DEBPz) exhibits high selectivity toward H 2 O 2 formation over H 2 O and reactive oxygen species (ROS), thereby significantly enhancing the stability of both the photocatalyst and the enzyme. As a result, the DEBPz/ rAae UPO photobiocatalytic system achieved robust and effective oxyfunctionalization reaction over 60 h, reaching a total turnover number of 142,000. This work underscores strategic control over both catalytic selectivity and system durability as a decisive factor in enabling robust, solar‐powered biotransformation for sustainable chemical synthesis.