Nickel-Catalyzed Atroposelective Cross-Electrophile Coupling of Aryl Halides: A General and Practical Route to Diverse MOP-Type Ligands

We
report a highly cross- and atroposelective coupling
between ortho-(chloro)­arylphosphine oxides and ortho-(bromo)­aryl ethers. This previously unknown asymmetric
nickel-catalyzed
reaction offers a direct route to highly enantioenriched axially chiral
biaryl monophosphine oxides that are difficult to access by other
means. These products can be readily reduced to generate chiral MOP-type
ligands bearing complex skeletal backbones. The utility of these chiral
ligands in asymmetric catalysis is also demonstrated.