Hydrogenation of alkynes from decyne and dodecyne (C-10-C-12) with the triple bond at C3, C4, C5, and C6 led to the corresponding alkenes on a boron-nickel catalyst modified by 1-phenyl-2,3-dimethyl-4-amino-5-pyrazolone (4-aminoantipyrene). The stereospecificity for formation of the cis-alkenes was 95-98%.