Abstract A practical hydrogenation of aldehydes mediated by an inexpensive and easily available base metal, copper, is reported. A copper complex associated with 1, 4-bis (diphenylphosphino) butane (DPPB) hydrogenates α, β-unsaturated aldehydes in a highly chemoselective fashion to give allylic alcohols with improved catalytic productivities. The reaction system was also effective for the conversion of simple aldehydes to the ...