Stereoselectivity in Reactions of Metal Complexes. Part XVII. Synthesis of three new optically active triamines: 2,6‐Bis{[(2S)‐2‐(hydroxymethyl)pyrrolidin‐1‐yl]methyl}pyridine, 2,6‐bis{[(2S)‐2‐(methoxymethyl)pyrrolidin‐1‐yl]methyl}pyridine, and 2,6‐bis{{(2S)‐2‐[(benzyloxy)methyl]pyrrolidin‐1‐yl}methyl}pyridine. X‐ray structure and equilibrium behaviour of their copper(II) complexes

Abstract

AbstractThe three new optically active triamines derived from 2,6‐bis(aminomethyl)pyridine, i.e. 2,6‐bis{[(2S)‐2‐(hydroxymethyl)pyrrolidin‐1‐yl]methyl}pyridine (3a), 2,6‐bis{[(2S)‐2‐(methoxymethyl)pyrrolidin‐1‐yl]methyl}‐pyridine (3b), and 2,6‐bis{{(2S)‐2‐[(benzyloxy)methyl]pyrrolidin‐1‐yl}methyl}pyridine (3c), were synthesized. The equilibrium behaviour in solution and CuII complex formation were studied by acidimetric titration and by UV/VIS and CD measurements. It was found that in aqueous solution, 3a can coordinate one of the CH2OH groups to CuII upon deprotonation. X‐Ray crystal structures were determined for the complexes [Cu(3a)Cl]ClO4·H2O, [Cu(3b)Cl]ClO4, and [Cu(3c)Cl]ClO4. In the solid state, coordination of both the OH and the alkoxy groups was observed, and the three ligands are pentacoordinated.