 The enhanced reactivity is attributed to the polarization of the carbonyl substrate by complexation to the lithium cation.The use of lithium borohydride is particularly advantageous in some preparations due to its higher chemoselectivity relative to other popular reducing agents such as lithium aluminium hydride.For instance, unlike lithium aluminium hydride, lithium borohydride will reduce esters, nitriles, lactones, primary amides, and epoxides while sparing nitro groups, carbamic acids, alkyl halides, and secondary/tertiary amides.