Diastereoselective Access to Ester-Substituted cis-Phenanthridinones via Hydrogen Atom Transfer-Involved 1,7-Enyne Bicyclization

An organophotoredox-catalyzed 1,7-enyne bicyclization for the cis-diastereoselective synthesis of ester-substituted phenanthridinones has been achieved through radical cascade cyclization involving 1,6-hydrogen atom transfer. This transition-metal- and oxidant-free one-pot protocol generates three distinct C-C bonds and two quaternary carbon centers.