Modified Hydroborate Agent: (2,2-Bipyridyl)(tetrahydroborato)zinc Complex, [Zn(BH4)2(bpy)], as a New, Stable, Efficient Ligand-Metal Hydroborate and Chemoselective Reducing Agent

(2,2ʹ-Bipyridyl)(tetrahydroborato)zinc complex, [Zn(BH4)2(bpy)], is a new white stable compound which has been used for efficient reduction of variety of carbonyl compounds such as aldehydes, ketones, acyloins, (alpha)-diketones and (alpha),(beta)-unsaturated carbonyl compounds (1,2-reduction) to their corresponding alcohols in acetonitrile at room temperature. Excellent chemoselectivity was also observed for the reduction of aldehydes over ketones with this reducing agent.