Zr-Mediated Cyclization of Alkynes as a Transferable Protocol for Constructing C2-Symmetric and Other Chiral Multisubstituted Cyclopentadienyl Ligands

Abstract

The geometric configuration of the chiral Cp ligand and any alteration in its structure consequently influence the corresponding catalyst performance. This synergistic relationship drives the search for new chiral ligands, and with this work, we deliver a transferable methodology for constructing chiral C₂-symmetric and other Cp-ligands. The methodology utilizes Negishi’s reagent to induce the cyclization of internal diynes derived from different chiral materials: (R)-BINOL, L-(+)-tartaric acid, and chiral primary amine. The subsequent reaction of the formed zirconium intermediate with diiodomethane gave a series of aryl-substituted chiral Cp-ligands. This approach allows structural modification of known ligands as well as the construction of completely new ones.