A new protocol is herein described for the direct generation of alkylated indolo/benzoimidazo[2,1-a]isoquinolin-6(5H)-one derivatives by using Hantzsch esters as alkylation radical precursors using a photoredox/K2S2O8 system. This oxidative alkylation of active alkenes involves a radical cascade cyclization process and a sequence of Hantzsch ester single electron oxidation, C–C bond cleavage, alkylation, arylation and oxidative deprotonation.
![Graphical abstract: Visible-light-promoted radical cascade alkylation/cyclization: access to alkylated indolo/benzoimidazo[2,1-a]isoquinolin-6(5H)-ones](http://hg.y866.cn/compound/lib/scimg/usr/1/D2OB01732F.jpg)