Flash Communication: Transfer Hydrogenation of Formic Acid to Methanol

An alternative route for the reductive conversion of formic acid to methanol via transfer hydrogenation (FATH) reaction is demonstrated. The FATH reaction is catalyzed by “N-heterocyclic carbene–pyridine–benzimidazolato”-based CNN pincer ligand-bound Ru complexes employing easily available alkali metal hydroxides and a renewable (bio)alcohol, ethylene glycol as the hydrogen donor. Unlike formic acid disproportionation where only one molecule of methanol is obtained from three molecules of HCOOH, the reported transfer hydrogenation route offers one molecule of methanol from one molecule of HCOOH, thus maintaining a better formic acid economy.