A Ni-catalyzed 1,2-acyl migration triggered by C–C bond cleavage was developed. The process of 1,2-acyl migration followed by olefin isomerization provides a convenient access to α,β-unsaturatedketones, which are well-known building blocks in organic synthesis. Experimental and computational studies show that the selective β-hydride elimination and Ni-hydride reinsertion play an essential role in