Photoelectrochemical Decarboxylative C–H Alkylation of Quinoxalin-2(1H)‑ones

Progress in photochemical and electrochemical decarboxylation has enabled the rapid construction of functionalized decarboxylated products under extremely mild conditions. The utility of these methods, however, is restricted by the energy of visible-light photons and the chemoselectivity of the electrodes, respectively. Herein, we report a protocol for the photoelectrochemical decarboxylative C–H alkylation of quinoxalin-2­(1H)-ones with good reactivity and selectivity. This protocol involves the use of iron, an earth-abundant metal, to catalyze decarboxylation via ligand-to-metal charge transfer. Furthermore, the reactions can be carried out with a 3 V battery as a power supply, revealing the remarkable simplicity and flexibility of this photoelectrochemical protocol. It offers a new paradigm for a convenient, green synthesis of valuable compounds from versatile carboxylic acid building blocks.