Chiral HPLC Separation, Absolute Structural Elucidation, and Determination of Stereochemical Stability of trans-Bis[2-(2-pyridinyl)aminophenolato] Cyclotriphosphazene.

Chiral high-performance liquid chromatography (HPLC) separation of trans-bis[2-(2-pyridyl)aminophenolato] dichlorocyclotriphosphazene was achieved and the absolute configuration of was assigned to be S,S by single-crystal X-ray structural analysis. The optically pure 1,2-diphenyl-1,2-ethanediolate derivatives (+)- and (-)- were synthesized by the reactions of and with (R,R)-hydrobenzoin, respectively, in refluxing toluene in the presence of an excess amount of triethylamine and a catalytic amount of 4-(dimethylamino)pyridine. The racemization of the enantiomers of and the epimerization of diastereomers of 2 were not observed in refluxing toluene neither under acidic nor basic conditions. The stereochemistry of was confirmed by the crystal structure of (+)- and bis[(4-methyl-2-pyridyl)oxy]cyclotriphosphazene derived from . Chirality 28:556-561, 2016.