Visible-Light-Induced Cascade Radical Trifluoromethylation/Cyclization/Dearomatization of Isocyanide-Containing Indoles: Synthesis of Trifluoromethylated 3-Spiroindolines

J Org Chem. 2024 Dec 20;89(24):18452-18463. doi: 10.1021/acs.joc.4c02349. Epub 2024 Dec 4.

Abstract

A visible-light-induced cascade radical trifluoromethylation/cyclization/dearomatization reaction between isocyanide-containing indoles and CF3Br has been developed to afford trifluoromethylated spiro[indole-3,3-quinoline] and spiro [indole-3,3-pyrrole] derivatives in good yields. The utility of the process is demonstrated by a scale-up experiment. The mechanism was proposed based on the control experiments. The protocol constitutes a novel and efficient route for the synthesis of trifluoromethylated 3-spiroindolenines with advantages of good generality and practical applicability, broad substrate scope, and green energy source.