Visible Light Promoted Cascade Cyclization Reaction via PCET Process: Easily Access Indoline-Fused Polycyclics

Abstract

An efficient protocol for the synthesis of indolinone-fused polycycles initiated by nitrogen-centered radicals (NCRs) has been developed. Amide radical was generated by proton-coupled electron transfer (PCET) under visible light. A series of lindole[1,2b] isoquinolinones were synthesized in up to 99% yield in "one-pot" construction of C-N/C-C bond through cascade cyclization. This protocol features with excellent step-and atom-economy, and obviating the use of transition metals and Brønsted bases, offering a mild and efficient photochemical pathway to synthesize polycyclic indolinones.