(R)-3,5-diCF3-SYNPHOS and (R)-p-CF3-SYNPHOS, Electron-Poor Diphosphines for Efficient Room Temperature Rh-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids

Two new atropisomeric electron-poor chiral diphosphine ligand analogues of SYNPHOS were prepared, and their electronic properties are described. These two ligands afforded high performance for the Rh-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds at room temperature.