An Improved Synthesis of Chiral 2,2′-Bipyridine Ligand C3-ACBP Without Column Chromatography.

Keywords: 2,2'-bipyridine ligand; C3-ACBP; column chromatography free; zinc chloride; gram scale EN 2,2'-bipyridine ligand C3-ACBP column chromatography free zinc chloride gram scale 2483 2486 4 07/31/23 20230817 NES 230817 Graph The chiral bidentate I N i , I N i -ligands play an essential role in asymmetric catalysis and great progress has been achieved in their synthesis and applications in recent decades. For both steps, column chromatography for the purification of the target products was conducted, which is impractical and unsustainable for the synthesis of chiral intermediate ( I S i , I S i )- B 3 b and the final bipyridine ligand at a large scale. To obtain the ligand, an excess amount of sodium hydroxide was added to precipitate the copper ion and neutralize the hydrochloride salt to release the free chiral bipyridine ligand. Comparing the mass of precipitate before and after dissociating zinc chloride, the ratio of ( I S i , I S i )- B 3 b to zinc chloride was calculated to be 1:1. [Extracted from the article]