In situ silane activation enables catalytic reduction of carboxylic acids.

We describe a catalytic system for the conversion of carboxylic acids into alcohols using substoichiometric zinc acetate and N -methyl morpholine, in combination with phenylsilane as the nominal terminal reductant. Reaction monitoring by 19 F NMR spectroscopy demonstrates that the reaction proceeds by mutual activation of the carboxylic acid and silane through the in situ generation of silyl ester intermediates.