Photo-induced synthesis of fluoroalkylated quinolinones via an iron-catalyzed LMCT decarboxylation process

Abstract

Herein, we report a practical synthetic method for the efficient preparation of fluoroalkylated quinoline-2,4-diones using N-(2-cyanophenyl)-N-methylacrylamides as substrates, fluoroalkyl carboxylic acids as reactants, and Fe(OH)(OAc)₂ as a catalyst. This reaction started with a photo-driven ligand-to-metal charge transfer (LMCT) process to decarboxylate the reactant and produce fluoroalkyl radicals, which then underwent radical cascade cyclization with the substrate. The target products were obtained in 55–91% yields. A gram scale experiment was also completed using a continuous-flow photocatalytic device.