Hydrogenation of alkynes in the presence of carbonyl compounds and imines using cationic rhodium(I) and iridium(I) precatalysts enables the formation of allylic alcohols and allylic amines, respectively. Through the use of hydrogenation catalysts modified by chiral ligands, allylic alcohols and allylic amines may be generated in highly optically enriched forms. Hydrogenative fragment couplings of this type circumvent the use of preformed organometallic reagents and avoid the generation of stoichiometric byproducts.