One-pot synthesis of benzo[a]phenanthridin-5-ones by photoinduced cycloaddition of 3-chloroisoquinolin-1-ones with styrenes

One-pot synthesis of benzo[a]phenanthridin-5-ones and benzo[k]phenanthridin-6-ones in fairly good yields was achieved by the photocycloaddition reactions of 3-chloroisoquinolin-1-ones and 3-chloroquinolin-2-ones with styrenes. The reactions were proceeded via photoinduced dechlorinative coupling of 3-chloroisoquinolin-1-ones and 3-chloroquinolin-2-ones with styrenes and subsequent photocyclization, oxidative aromatization.