(1R,2R)-N,N'-Bis[3-oxo-2-(2,4,6-trimethylbenzoyl)butylidene]-1,2-diphenylethylenediaminato Cobalt (II) (CAS# 263260-24-8) is an optically active cobalt(II) catalyst, used in enantioselective CO2 fixaton by assisting in the carbonation of racemic epoxides in the presence of amine bases.