Transition-metal-free radical fluoroalkylation of isocyanides for the synthesis of tri-/di-/monofluoromethylated phenanthridines

A mild and transition-metal-free protocol is herein presented for the preparation of 6-fluoroalkylphenan-thridines and this reaction can be readily scaled up to the gram level. The easy-handling sodium tri-, di-, and monofluoromethanesulfinates are used as efficient radical fluoroalkylation reagents under ambient conditions. In the presence of the organic photoredox catalyst N-methyl-9-mesityl acridinium, a range of desired products were afforded in satisfactory yields upon visible-light irradiation.