DFT Study of Mechanism and Stereochemistry of Nickel-Catalyzed <i>trans</i>-Arylative Desymmetrizing Cyclization of Alkyne-Tethered Malononitriles
Yu-Qing Zheng, Chen‐Long Li, Wen‐Bo Liu, Zhi‐Xiang Yu
Abstract
Present here is a density functional theory (DFT) study of the mechanism and origin of enantioselectivity of Ni-catalyzed desymmetric cyclization of alkyne-tethered malononitriles and aryl boronic acids. The reaction starts from transmetalation and arylnickel addition, followed by trans to cis isomerization to give cis-alkenyl nickel species. The stereodetermining step is the CN insertion, which prefers a transition state with the bystander CN group staying away from the ligand to reduce steric repulsion, and gives the final (R)-product.
Topics & Concepts
ChemistryAlkyneSteric effectsTransmetalationIsomerizationCatalysisNickelStereochemistryCycloisomerizationDensity functional theoryArylLigand (biochemistry)Medicinal chemistryComputational chemistryOrganic chemistryAlkylBiochemistryReceptorAsymmetric Synthesis and CatalysisAsymmetric Hydrogenation and CatalysisChemical synthesis and alkaloids