Aqueous room-temperature gold-catalyzed chemoselective transfer hydrogenation of aldehydes

A highly efficient, aqueous, room temperature, formate-mediated TH of aldehydes catalyzed by supported gold nanoclusters was reported. A mixture of aldehyde, metal catalysts, and formate salts, water was put into a flask fitted with a magnetic stirring bar and a reflux condenser. After the mixture was stirred at 25°C for a given reaction time, the product mixtures were extracted with Et₂O for 3 times and analyzed. The identification of the products was performed by using a GC-MS spectrometer comparing with commercially pure products. For isolation, the combined organic layer was dried over anhydrous Na₂SO₄, concentrated, and purified by silica gel column chromatography to give the product. A good linear correlation for the rate as a function of CeO₂ surface area was observed.