Zinc-Mediated Efficient and Selective Reduction of Carbonyl Compounds

Abstract

We herein describe for the first time that an optimized combination of Zn and NH4Cl can be used for the selective reduction of aldehydes and ketones to the corresponding alcohols. The aldehyde and keto groups are selectively reduced in the presence of azide, cyano, epoxy, ester, and carbon–carbon double-bond functional groups. A broad functional-group compatibility, chemoselective reduction of aldehydes in the presence of ketones, and selective reduction of isatins at the C3 carbonyl group are the highlights of the present method. Simple yet unknown! Aldehydes and ketones can be easily reduced to the corresponding alcohols with Zn/NH4Cl, which is used for pinacol coupling reactions. Chemoselective reduction of aldehydes in the presence of ketones is achieved. Isatins can be efficiently reduced at the C3 position.