A series of novel C2-symmetric bis (thiazoline) ligands with a diphenylamine backbone as a linkage between two thiazoline rings were synthesized by the use of the simple reagent phosphorus pentasulfide. Their application in the catalytic asymmetric Henry reaction of α- keto esters was investigated with comparison to the corresponding bis (oxazoline) ligands. Cu (II)–bis (oxazoline) complexes furnished moderate enantioselectivities (up to 60% ee), ...
