The nickel-catalyzed coupling of enones or enals with alkynes in the presence of slime and titanium alkoxide reductants provides direct access to skipped diene products. The process involves a net four-electron reductive coupling and proceeds with deoxygenation of the starting enone or enal. A new class of well-defined nickel(0) precatalysts bearing an unhindered N-hetero-cyclic carbene ligand, which was developed in optimization of the process, is essential for the efficiency of the transformation. The strategy allows the high reactivity of alpha,beta-unsaturated carbonyl substrates to be utilized in couplings with simultaneous extrusion of the oxygen atom, thus enabling a traceless strategy for alkene installation.