Synthesis of Axially Chiral 2,2′-Bisphosphobiarenes via a Nickel-Catalyzed Asymmetric Ullmann Coupling: General Access to Privileged Chiral Ligands without Optical Resolution

• DOI: 10.1021/jacs.0c12843
• Publication Date: 2021-01-15T04:41:07Z
• Authors: Ziqing Zuo; Raphael S. Kim; Donald A. Watson
• Keywords: Axial symmetry; Axial Chirality

We report an asymmetric homocoupling of ortho-(iodo)arylphosphine oxides and ortho-(iodo)arylphosphonates resulting in highly enantioenriched axially chiral bisphosphine bisphosphonates. These products are readily converted to biaryl bisphosphines without need for auxiliaries or optical resolution. This provides a practical route the development previously uninvestigated atroposelective ligands. The conditions have also proven effective dimerization other, non-phosphorus-containing aryl halides.