In this particular method, the substrate is treated with a hydrosilane and auxiliary reagent, often a strong acid, resulting in formal transfer of hydride from silicon to carbon.
Tertiary alcohols undergo facile reduction using boron trifluoride etherate as the Lewis acid.
[2] Primary alcohols require an excess of the silane, a stronger Lewis acid, and long reaction times.
[8] Polymeric hydrosilanes, such as polymethylhydrosiloxane (PHMS), may be employed to facilitate separation of the reduced products from silicon-containing byproducts.
[9][10] Enantioselective reductions of ketones may be accomplished through the use of catalytic amounts of chiral transition metal complexes.
[13] Esters may be reduced to alcohols under conditions of nucleophilic activation with caesium or potassium fluoride.
[18] Other functional groups that have been reduced with hydrosilanes include amides,[19] and α,β-unsaturated esters[20] enamines,[21] imines,[22] and azides.