Photocatalytic [2+2+m] Cyclization of 2-Cyanoaryl Acrylamides with 2-Bromocarbonyls Involving C(sp³)-H Functionalization

An oxidant-free photocatalytic [2+2+m] cyclization of 2-cyanoaryl acrylamides with 2-bromocarbonyls is reported, enabling the assembly of biologically important N-heterocycle-fused quinolinones including benzo[1,6]naphthyridinones and pyrrolo[3,2-c]-quinolines. This photocatalytic protocol proceeds through a radical relay pathway including alkene difunctionalization along with an intramolecular cyano insertion and subsequent site-specific functionalization of inert C(sp(3))-H bond enabled by cyano-derived iminyl radical-mediated 1,n-hydrogen atom transfer. Notably, this transformation selectively formed two distinct C-C bonds, one C-N bond, and one quaternary carbon center in a one-pot procedure.