Nickel-Catalyzed Asymmetric Ullmann Coupling for the Synthesis of Axially Chiral Tetra-ortho-Substituted Biaryl Dials
作者:Wen-Wen Chen、Qian Zhao、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ol1000632
日期:2010.3.5
asymmetric Ullmann coupling of bis-ortho-substituted arylhalides is described. With the chiral BINOL-based monodentate phosphoramidite ligand, the reaction allows atropoenantioselective synthesis of a series of axially chiral tetra-ortho-substitutedbiaryl dials. By taking advantage on this asymmetric Ullman coupling as a key stereogenic axis-forming reaction, the formal synthesis of (+)-isoschizandrin