Aldehydes compounds selective converted to 1,1-diacetates as protective reagent with SiO2@FeSO4 nano composite as effective nano catalyst at room temperature under solvent-free condition and acetic anhydride (Ac2O) as acetylation reagent. This method provides several advantages, such as low cost of the nano catalyst, high yields, short reaction time, chemoselective protection of aldehydes and operational simplicity. Aromatic and aliphatic, simple and conjugatedaldehydes were protected with excellent yields. In addition, chemoselective reductive acetylation of aldehydes over ketones was achieved perfectly with the reagent at room temperature.

As reduções de compostos carbonilados estruturalmente diferentes, como aldeídos, cetonas, enais alfa,beta-insaturados e enonas, alfa-dicetonas e acyloins foram realizadas eficientemente com borohidreto de sódio, na presença de SiO2 úmido (30% m/m), sem solvente. As reações ocorreram em temperatura ambiente ou a 75-80 ºC, tendo-se obtido excelentes rendimentos dos produtos correspondentes. A redução quimiosseletiva de aldeídos na presença de cetonas foi obtida com êxito, usando-se este sistema de redução.

Reduction of structurally different carbonyl compounds such as aldehydes, ketones, alpha,beta-unsaturated enals and enones, alpha-diketones and acyloins were accomplished efficiently by sodium borohydride in the presence of wet SiO2 (30% m/m) under solvent free condition. The reactions were performed at room temperature or 75-80 ºC with high to excellent yields of the corresponding products. The chemoselective reduction of aldehydes over ketones was achieved successfully with this reducing system.