Photoinduced ligand to metal charge transfer enabling cerium mediated decarboxylative alkylation of quinoxalin-2(1<i>H</i>)-ones

Abstract

Here, we report the cerium-mediated decarboxylative alkylation of quinoxalin-2(1<i>H</i>)-ones utilizing feedstock carboxylic acids as a radical precursor <i>via</i> photoinduced-LMCT. This operationally simple protocol overcomes the limitation of the direct use of carboxylic acids to access alkyl radicals. Spectroscopic investigations reveal the photoinduced LMCT and CO₂ evolving events. We have utilized a broad range of alkyl carboxylic acids (1° to 3° acids), amino acids and pharmaceutically-important acids as a coupling partner to synthesise the desired alkylated heterocyclic product in good to excellent yields.