Phenylphenothiazine-Based Porous Organic Polymers as Visible-Light Heterogeneous Photocatalysts for Switchable Bromoalkylation and Cyclopropanation of Unactivated Terminal Alkenes

We report the design and synthesis of porous organic polymers (POPs) based onN-phenylphenothiazine (PTH),which typically requires ultraviolet-light irradiation, as a class of purely organic, stable, and reusable visible-light heterogeneousphotocatalysts. The extended pi-conjugation and polymeric networks not only enhance visible-light absorption but also accelerate thereaction rates. More intriguingly, the switchable bromoalkylation and cyclopropanation of unactivated terminal alkenes could beachieved by simply tuning the solvents under PTH-POP catalysis. Theflexible manipulation of the resultant products furtherdemonstrates its synthetic utility