Photoinduced N‑Heterocyclic Nitrenium-Catalyzed Single Electron Reduction of α-Chloro Esters for Phenanthridine Synthesis

Abstract

Visible-light photoredox catalysis has revolutionized synthetic methodologies by enabling sustainable radical-mediated transformations under mild conditions. Herein, we report a catalytic protocol employing N-heterocyclic nitrenium (NHN) iodide salts to drive the photoreduction of α-chloro esters, generating alkyl radicals that participate in annulation with 2-isocyanobiaryls for the modular synthesis of phenanthridine derivatives. This approach is characterized by easily available NHNs and operational simplicity.