A visible light promoted cascade cyclization reaction via a PCET process: easy access to indolinone-fused polycycles

Abstract

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