The Zn-promoted direct reduction of various ketones, including alkyl aryl ketones, a-and bketo esters, a-and b-keto amides, into the corresponding alcohols with polymethylhydrosiloxane (PMHS) in protic conditions is reported. The reaction proceeds chemoselectively under smooth conditions, with simple catalyst combinations based on a zinc precursor [ZnEt 2 , Zn(OMe) 2 , Zn(OH) 2 ] and a 1,2-diamine ligand, e.g., N,N'-dibenzylethylenediamine (dbea). The reaction rates are significantly faster than under aprotic conditions. For b-keto esters and amides, the use of an excess of PMHS is required. Moderate enantioselectivities (ee up to 55%) have been obtained using a variety of enantiopure diamine ligands. Two mechanisms are proposed for the new catalytic reaction, on the basis of the synthesis of [(diamine)Zn(alkoxide) 2 ] complexes which are models of the possible reaction intermediates and a study of their activity.