Synthetic studies on pyrrolophenanthridone skeleton from 1-benzoyl-7-iododihydroindole derivatives using palladium-assisted biaryl coupling reactions

The biaryl coupling reaction of 1-benzoyl-7-iododihydroindole derivatives using Pd reagent was examined. 1-[(1,3-Benzodioxol-5-yl)carbonyl]-7-iodo-2,3-dihydroindole gave 4,5-dihydro-7H-[1,3]dioxolo[4,5-k]pyrrolo[3,2,1-de] phenanthridin-7-one, which was formed by connection to a more hindered carbon, as a major product. 1-(3,4-Dimethoxybenzoyl)-7-iodo-2,3-dihydroindole gave oxoassoanine and 10,11-dimethoxy-4,5-dihydropyrrolo[3,2,1-de]-phenanthridin-7-one in an almost equal ratio.