A series of novel C 2 -symmetric chiral pyridine β-amino alcohol ligands have been synthesized from 2,6-pyridine dicarboxaldehyde, m-phthalaldehyde and chiral β-amino alcohols through a two-step reaction. All their structures were characterized by 1 H NMR, 13 C NMR and IR. Their enantioselective induction behaviors were examined under different conditions such as the structure of the ligands, reaction temperature, solvent, reaction time and catalytic amount. The results show that the corresponding chiral secondary alcohols can be obtained with high yields and moderate to good enantiomeric excess. The best result, up to 89% ee, was obtained when the ligand 3c (2S,2′R)-2,2′-((pyridine-2,6-diylbis(methylene)) bisazanediyl))bis(4-methyl-1,1-diphenylpentan-1-ol) was used in toluene at room temperature. The ligand 3g (2S,2′R)-2,2′-((1,3-phenylenebis(methylene))bis(azanediyl))bis(4-methyl-1,1-diphenylpentan-1-ol) was prepared in which the pyridine ring was replaced by the benzene ring compared to 3c in order to illustrate the unique role of the N atom in the pyridine ring in the inductive reaction. The results indicate that the coordination of the N atom of the pyridine ring is essential in the asymmetric induction reaction.

Chiral Pyridine -Amino Alcohols as Chiral Ligands. -(ZHANG, W.; TANG*, R.; YU, H.; GAO, S.; Appl. Organomet. Chem. 28 (2014) 7, 545-551, http://dx.

A novel polyamine polycarboxylic ligand (L) with imidazole and pyridyl moieties and its corresponding complexes Na 3 EuLCl 3 · 6H 2 O and Na 3 TbLCl 3 · 6H 2 O, on to which Eu(III) and Tb(III) were bound via coordination, were prepared and characterized by FT-IR, 1 HNMR, TG-DTA and CHN elemental analysis. The thermogravimetric analysis shows the Eu (III) and Tb(III) complexes have good thermal stabilities with decomposition temperatures 380 and 398 • C, respectively. The luminescence properties of the complexes show the ligand has excellent antenna effect to sensitize the lanthanide ions while using ethyl p-dimethylaminobenzoate in ethanol as reference sample, the quantum efficiency of the Eu(III) and Tb(III) complexes are 0.264 and 0.280 in the DMSO at room temperature, respectively. The interactions of the complexes with bovine serum albumin (BSA) were analyzed by fluorescence measurements under physiological conditions. The UV-vis absorbance and the Stern-Volmer analysis indicate that the main quenching mechanism of BSA by the complexes is a static quenching procedure. The binding constants, binding site number at different temperatures were calculated by Van't Hoff equation, which confirms that the Van der Waals and hydrogen bond interactions are mainly impulse to the formation of complexes BSA-L coordination compound. Furthermore, the effect of complex on the conformation of BSA was analyzed according to synchronous fluorescence and circular dichroism (CD) spectra.