Development of 1,4-Azaborine-Derived Biaryl Phosphine Ligands with P-central and Axial Chirality

Abstract

New P-central and axially chiral 1,4-azaborine-derived biaryl phosphine Senphos ligand were designed and synthesized. The separation of diastereomers and enantiomers of those ligands was achieved through preparative recycling HPLC, and the separation efficiency was increased via the use of a borane protecting group. The effect of solvents and diamine ligands in enantioselective ligand synthesis was examined. The absolute configuration of the key enantiomer was confirmed via X-ray crystallography analysis. The catalytic performance of these newly synthesized ligands was evaluated through several benchmark reactions, demonstrating their potential in enantioselective catalysis.