A　facile　and　efficient　quinoline-fused　4H-benzo[b][1,4]oxazine　has　been　successfully　fabricated　through　an　oxidative　O-arylation,　Pd-catalyzed　double　N-arylation　of　4-hydroxyquinoline　derivatives　and　trivalent　aryl　iodides.　Diversified　fused　heterocycles　could　be　easily　constructed　in　overall　high　isolated　yields　with　great　substrate　scope.　The　afforded　heteroatom-＇doped＇phenoxazine　3　demonstrated　high　molar　absorptivities　and　excellent　stability　and　redox　reversibility.　These　phenoxazine　analogues　therefore　could　be　utilized　as　promising　catalysts　in　the　photoredox　catalyzed　perfluoroalkylation　of　heteroarenes　and　photopromoted　radical　polymerization　(OATRP).　©　2021　American　Chemical　Society.