The synthesis of anticancer sulfonated indolo[2,1-<i>a</i>]isoquinoline and benzimidazo[2,1-<i>a</i>]isoquinolin-6(5<i>H</i>)-ones derivatives <i>via</i> a free radical cascade pathway

Abstract

A facile CuBr₂ induced radical relay addition/cyclization of activated alkenes with substituted-thiosulfonates has been achieved, leading to a broad range of sulfonated indolo[2,1-<i>a</i>]isoquinolines and benzimidazo[2,1-<i>a</i>]isoquinolin-6(5<i>H</i>)-ones in moderate to good yields. In particular, some compounds exhibit bioactivity against cancer cell lines. This protocol shows advantages of low-cost, base-free, simple operation, and broad functional group tolerance.