Synthesis of Axially Chiral 2,2′-Bisphosphobiarenes via a Nickel-Catalyzed Asymmetric Ullmann Coupling: General Access to Privileged Chiral Ligands without Optical Resolution
作者:Ziqing Zuo、Raphael S. Kim、Donald A. Watson
DOI:10.1021/jacs.0c12843
日期:2021.1.27
We report an asymmetric homocoupling of ortho-(iodo)arylphosphine oxides and ortho-(iodo)arylphosphonates resulting in highly enantioenriched axially chiral bisphosphine oxides and bisphosphonates. These products are readily converted to enantioenriched biaryl bisphosphines without need for chiralauxiliaries or optical resolution. This provides a practical route for the development of previously uninvestigated
Michaelis–Arbuzov reaction of carboxylicacids and triaryl phosphites for preparing arylphosphonates under anhydride-free conditions has been reported. In this context, triaryl phosphites serve as both reagents for activating the carboxylicacids and substrates for the reaction. There have been no reports to date of efficient and direct methods for the in situ activation of carboxylicacids using triaryl phosphites