Asymmetric coupling reactions of aryl electrophiles towards atropisomeric biaryls employing chiral Co and Ni-catalysts

The synthesis of axially chiral biaryls, an important structural motif in different areas, via atroposelective coupling reactions usually requires the application of Pd catalysts. To avoid precious metals, alternative methods employing earth-abundant, 3d transition metal catalysts have been developed. This review summarizes the progress on these Ni-catalyzed cross-coupling reactions and Ni and Co-catalyzed reductive coupling reactions towards axially chiral biaryls. The synthesis of axially chiral biaryls, an important structural motif in different areas, via atroposelective coupling reactions usually requires the application of Pd catalysts. To avoid precious metals, alternative methods employing earth-abundant, 3d transition metal catalysts have been developed. This review summarizes the progress on these Ni-catalyzed cross-coupling reactions and Ni and Co-catalyzed reductive coupling reactions towards axially chiral biaryls.