The　external　oxidant-free　exploitation　of　abundant　alkane　feedstocks　as　alkyl　radical　precursors　remains　a　topic　of　high　interest　in　synthetic　communities.　Here,　we　report　a　Ce-catalyzed　electrophotoredox　radical　addition/cyclization　cascade　for　the　incorporation　of　unactivated　alkanes　to　produce　alkylated　benzimidazo-fused　isoquinolinones　and　other　N-containing　polycycles.　Compared　with　previous　works　employing　prefunctionalized　alkyl　radical　precursors,　this　electrophotocatalytic　protocol　features　high　step-economy.　The　external　oxidant-free　conditions　accompanied　by　the　generation　of　H2　as　the　only　byproduct　further　highlight　the　high　redox-　and　atom-economy　of　this　catalytic　protocol.　(c)　2022　Elsevier　Inc.　All　rights　reserved.