C2-chiral dinucleating ligands with a 3,6-disubstituted pyridazine core

Reaction of the 3,6-bis(tosyloxymethyl)pyridazine (1) with two equivalents of (1R-2S)-norephedrine or (1S-2R)-1-amino-2-indanol leads to the formation of C2-chiral dinucleating ligands containing a 3,6-disubstituted pyridazine core flanked by aminoalcohol pendant arms, namely 3,6-bis((1R-2S)-(2-hydroxy-1-methyl-2-phenyl-ethyl)aminomethyl)pyridazine (2) and 3,6-bis((1S-2R)-(2-hydroxy-indan-1-yl)aminomethyl)pyridazine (3). As shown by spectrometric titration experiments as well as ESI/MS, ligands 2 and 3 bind copper(II) cations to form dinuclear complexes.