C–H bond functionalization reactions enabled by photobiocatalytic cascades

Light may participate in biocatalytic processes either by direct light-induced biocatalysis or by cascading light-induced chemical reactions with biocatalytic ones, which are acknowledged as photocatalysis. As it combines the strength of chemocatalysis and biocatalysis, photobiocatalysis provides attractive advantages towards green synthesis in terms of atom efficiency, selectivity and promiscuity. Particularly, photobiocatalysis has demonstrated its unique power in C–H bond functionalization. Versatile approaches, mostly via combining photocatalytic and biocatalytic processes in one pot, have been developed to synthesize a broad range of valuable compounds. The reactions include hydroxylation, halogenation, amination and ring-expansion of C–H bonds. In this mini-review, we critically summarize recent advances of photocatalytic C–H bond functionalization by combining photocatalysts and enzymes in cascade reactions, in hope that the advantages and potentials offered by photobiocatalysis will trigger further enthusiasm in the research field of light-induced cascade reactions.