Giese reaction constitutes one of the most widely used methods for the construction of C–C bonds. However, this strategy typically requires the utilization of prefunctionalized radical precursors, toxic reagents or transition-metal catalysts. Here we report a metal-free, atom and redox-economical approach for the assembly of C–C bonds between N,N-dimethyl-anilines and electron-deficient alkenes using oligofluorene-based hypercrosslinked polymers (HCPs) as the recoverable and reusable photocatalysts under visible-light irradiation.