4,5,6-Tetrakis (3,6-di-tert- butyl-9H-carbazol-9-yl)-isophthalonitrile (4CzIPN-Bu-t) was developed as a photocatalyst for the phosphorus-radical-initiated cascade cyclization reaction of isocyanides. By using 4CzIPN-Bu-t as catalyst, we developed a visiblelight-induced proton-coupled electron transfer strategy for the generation of phosphorus-centered radicals, via which a wide range of phosphorylated phenanthridines, quinolines, and benzothiazoles were successfully constructed.