DFT calculations rationalize regioselectivity and chemodivergence in nickel-catalyzed couplings of aldehyde, alkyne, and dialkylsilane/trialkylsilane

• Mechanism of nickel-catalyzed couplings of aldehyde, alkyne, and dialkylsilane/trialkylsilane. • Rationalizing the regioselectivity and chemodivergence in nickel-catalyzed couplings. • Proposing a new and essentially different mechanism from that for the formation of silacyclopentenes in nickel-catalyzed couplings using dialkylsilane as reducing agent. DFT calculations were performed to understand the regioselectivity and chemodivergence in the nickel-catalyzed three-component coupling of aldehyde, alkyne, and dialkylsilane/trialkylsilane to synthesize silylated allylic alcohols and silacyclopentenes. The calculated results proposed a new mechanism for the formation of silacyclopentenes, rationalized the observed regioselectivity and chemodivergence, and identified the both the regioselectivity-determining step and the rate-determining step. DFT calculations provide new insights into the mechanism of Ni-catalyzed three-component couplings of aldehyde, alkyne, and dialkylsilane/trialkylsilane, and rationalize the experimentally observed regio- and chemo-selectivities.